# EPA wood furnace - Caddy



## Beno

Hi there,

I'd like to know the opinion of this forum about Caddy - E.P.A. wood or wood-electric/oil combination furnace:
http://www.psg-distribution.com/product.aspx?CategoId=16&Id=335
http://www.psg-distribution.com/product.aspx?CategoId=17&Id=377

The Caddy has a 3.5 cu.ft. firebox and you can buy it with oil/electric backup. I saw few posts here, but it seems that no one has actually used it.
The house is a 2 storey 3600 sq.ft. located near Ottawa, Canada. This looks attractive because is cost effective, I'll have the ductwork that I can use for A/C, I can solve also the ventilation problem w/o ducts for HRV/ERV, I'll not have to create complex plumbing installations for hydronic radiant heating.
Also, should I go with oil or electric combo? Another advantage, is built in Canada.

Thanks,
Beno


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## Todd

I was looking at those last night. It's nice to see an EPA rated wood furnace with a fire viewing glass door. I like the mini caddy. Any idea what they cost?


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## BrotherBart

U.S. Stove Company is selling the exact same furnace as their Hotblast 1950 model. Hopefully it will make it to Tractor Supply like their non-EPA furnace did.


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## laynes69

There were some on ebay not too long ago for 1,500.00 which is cheap. They are close to 3000 through us stove. If I ever replace my wood furnace I will buy one of these. I have my current wood furnace ducted in like one of these and its a sweet setup. I could see these things heating 3500 square feet, if the ductwork is sized correctly.


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## stoveguy2esw

shows 73 % efficiency , but does not show particulate matter results , is this an exempt unit? it should be due to being a furnace , but they show it on the website as an "epa" unit to be certified it must have an epa "GPH" rating, if it has one i didnt find it on the website , nice looking furnace though , i wonder who is building them.


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## BrotherBart

6.56 GPH.


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## karl

Yukon-eagle.com has one that runs on wood/coal  and natural gas/ heating oil.   So if you forget to fill it with wood it will switch automatically to gas or oil.  Plus it will automatically light the wood fire too.  It's expensive though.


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## KeithO

Because it is exempt, one has to be cautions that it actually meets "regular" EPA specifications.   Vogelzang, which makes some of the worst junk on the face of the earth, also claims to meet "EPA requirements for exempt woodstoves" which is of course completely meaningless.

The design features one needs for a good design are easy to look for:  Lots of refractory, heated secondary air, good sealing around all openings and joints to avoid excessive leakage etc.  The firebrick is certainly there.


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## Beno

From EPA site:
Caddy (duct furnacea0
Noncatalytic
6.6 (Emmisions)
63 % (Efficiency)
12000-52900 (Heat BTU)
3/19/2008

I'd like to know if this/a wood furnace can work during a power outage? My guess is not, that means I'll have to have a generator?


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## webbie

I'm very familiar with Yukon - decent unit, but virtually the same model they designed and sold since 1978....way before EPA standards came into effect......what we need now if the 70+% efficient furnace using the downdraft system that Harman, VC, Travis and others are starting to use - word on the street says this offers a fairly even burn cycle - and LONG burns....

But at a good price ($3000 seems high), the caddy is one of the only units out there with decent clean burning built-in.


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## laynes69

The caddy is around 2500 or 2700 for the list price. Its more for US Stove. I do believe that US Stove bought into the design of the caddy, cause for a while the caddy was the only epa wood furnace. They have 3 tubes above the firebox where I think the high combustion occurs. You just open a door and run a small brush through them to clear the soot. They don't require electricity for the high combustion, just to push the heat. We still keep our wood furnace going during a power outage. We turn the draft down and it acts as a gravity heater. When the power comes back on we get the blower back. I really like the idea where the ducting can be installed from either side of the furnace. Just use the main furnaces blower, and you wouldn't need one on the unit. I know the caddy can be ordered with or without a blower, but don't know about usstoves.


http://www.usstove.com/proddetail.php?prod=1950


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## Gibbonboy

The Caddy is $2,349 from here: http://www.barbecues.com/web/catalog/product_detail.aspx?pid=187795

Not sure what the shipping would set you back. Barring the introduction of a better and less-expensive EPA wood furnace, I'll be getting one of these in a couple more years. I currently have a US Stove wood furnace, I certainly wouldn't spend MORE than the Caddy costs to get US Stove's crap quality. My current furnace is perfectly functional, and I am happy with the way it performs, it's just made sloppily and from shoddy materials. Their smaller furnaces (Hotblast, 1557, etc.) are worse- the doors are made from sheet metal, no firebrick, just basically guaranteed to last 5-10 years and be scrapped. The Caddy will cost less than a thousand dollars more, and if they last 10 years, they're completely worth it to me. 

There was also rumor about a bunch of OWB's that meet EPA standards, but I don't think that particular market is open to such ideas yet. Hard to burn skidder tires and bale wrap in an EPA stove!


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## coppermouse

I am looking into one of these stoves, The USSC 1950 is exactly the same if you look at the manual it is exactly the same, except for one picture the shows the company name when cleaning the heat exchanger. I checked at Tractor Supply yesterday and they can order in the US Stove for $1795 + $175 shipping (quite a bit less than the website list it for (3K)
But I was also looking at the woodchuck, it is 73% efficient. How does that stove compare? How aout the Kuuma Vaporair ?


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## Beno

Few questions regarding the installation of the Caddy.
1. From the Caddy I'll need 4 elbows (45 degrees each) to connect to the 7" flue pipe. Is this number of 45* elbows acceptable? They will all be in the utility room on first floor (no basement in the house).
2. The manual recommends 2 feet clearance on the sides of the furnace and also at the back, and 4 feet in the front. Are these mandatory? What if I have only one foot clearance (sides and back) ?
3. Since there is no basement, I plan to use 5" insulated ducts that will go through the open web floor trusses, and will come out on the first floor with vents placed on the ceiling (first floor only). Is this location of the vents (on the ceiling) OK? The rooms are 9 ft height.

Thanks,
Beno


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## laynes69

Well the caddy is best used as a add-on. Do you currently have a furnace? The elbows sounds okay, but also depends on your draft. With it being an epa stove, draft would need to be up to par. As far as clearance, if its in the manual, then yes you need those clearances. I would assume thats for combustables. So if the manual calls for 2 feet to combustables, then 1 foot is not enough. The ceiling is the worse place to install ducts, only because heat rises. It will make it much harder to heat the home this way. If it would be your only option, then use ceiling fans to help push the air down. Are the insulated ducts flexable? If so you can't use them with the furnace. With a wood furnace you need to follow the plenum and duct clearances because of the high temps. If you have a power outage, then your ducts could get too hot. With a furnace that can push close to 140,000 btus, its very important to follow clearances.


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## Beno

Would you recommend to buy the Caddy with the oil backup? This is a new construction.


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## Gooserider

Beno said:
			
		

> Would you recommend to buy the Caddy with the oil backup? This is a new construction.



If it's new construction, are you choosing between the Caddy w/ oil backup, or using a second furnace for backup? (or not having a backup?)

I'm not an expert, but I would say that it is essential to have a "conventional" heat backup, no matter how dedicated you are to burning.  Most mortgage places will require it, and I think it's smart just because you won't always want to be home to feed the fire.

That said, it comes down to a question of tradeoffs...

Which would cost more?  The Caddy w/ backup, or two seperate furnaces?

Which would take up more floor real estate for both the unit(s) and the associated plumbing?

How do the oil burning efficiencies compare?  My understanding is that the Caddy oil side is less efficient than a modern standalone unit, but I could easily be wrong.  If there is a difference, how big of an issue is it?  If the oil only burns a little bit each year, then efficiency shouldn't be a big concern.  If the oil sees heavy use, then it is...

What would the stack requirements be for each approach.  I know for seperate units you'd be required to have separate flues (though the oil burner could be power vented) - what about the Caddy?

Etc.

I don't know that the Caddy type boiler would be my first choice in heating systems, but if it was, and there were no reason not to, I would probably be inclined towards the combo approach, but I don't feel like I know enough to make a strong recomendation either way.

Gooserider


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## elkimmeg

Beano I got to run back to work but there are some serious flaws in your planning  clearances  issues no discussions of combustion air ceiling feeds no mention of returns  the plentum conditions no flexible duct work can be used with a wood fire furnace  I would have to read that manual and apply code and then common sense of installation. before anyone can advise of how you plan to use that system.. I  don't know if reduced neclosures apply to furnaces plus code also requires distances for servicing lots of issues to resolve here


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## webbie

Beno said:
			
		

> Would you recommend to buy the Caddy with the oil backup? This is a new construction.



I would have to look carefully at the oil setup - some multi-fuels are not set up well on the "old" fuel.

Please keep in mind what others have said - you must use metal ducts only with wood furnaces, and the clearances are strict - usually 6" or more from the plenum, then reducing to 2" and then 1" depending on how far from the furnace. As Elk said, check the manual - it MUST specify this.


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## Beno

Hi there,

A couple more questions:
1. During a power outage, can you use somehow the wood furnace to cook/heat some food?
2. I spoke with a builder who said that for a 3600 sq.ft. the ductwork will be about $9000. Is this a reasonable price? (Seems high to me)

Thanks!


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## Gooserider

Beno said:
			
		

> Hi there,
> 
> A couple more questions:
> 1. During a power outage, can you use somehow the wood furnace to cook/heat some food?
> 2. I spoke with a builder who said that for a 3600 sq.ft. the ductwork will be about $9000. Is this a reasonable price? (Seems high to me)
> 
> Thanks!



First off, I've moved this thread to the "Boiler Room" which is more appropriate for "whole house" type heating appliances.

As to your questions...

#1.  I don't know but I would consider it a less than optimal approach.  Presumably you could stick some things into the firebox and heat them that way, but I don't know how feasible that is.  I would hope that the unit would be well enough insulated that it wasn't useful to put something on top of it, since you'd be wanting all the heat to go into the air ducting.  I suspect that you would be far better off to get one of those Coleman "suitcase" stoves.

A more important question is what the system will do for HEATING during a power failure...  I am not an expert, but from reading some of the other BR threads, I know there is concern about overheating in the event of a power failure as your heat distribution system will quit, but unlike an oil or gas burner, a wood fire doesn't go out when the power does...  This is definitely an issue for the boiler people, I don't know if it is for the hot air folks, although you'd still have to worry about heating the house.

2. Never priced ducting, haven't the foggiest.  Hopefully some of the others here will have a better idea of how to spec the job and what to pay for it.

Gooserider


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## laynes69

Some units have removal side panels incase of a power outage. This way it helps keep the furnace a little cooler. We have had the power go out here and our furnace will heat somewhat, but I really damper it down during an outage. The caddy has insulated sides, so the only place for the heat to go is out the top. I have heard of people who have added a relay that when the power goes out a door in the plenum opens up. I've never done it myself though. The clearances on ducting are important due to power outages and potential heat. Last year, or maybe 2 years ago I got a quote for ductwork in our house. It was 3200 low and 3700 high. I did it for 1,200 dollars. Its important when installing ductwork to have little static pressure in the ducts. If its undersized it will kill the blowers and furnaces, Very important to be sized right. Another thing is I would have a main furnace and use the caddy as a backup. I wouldn't get the elements in it. What if the elements went out in the caddy? I know by experience that the setup of the caddy is made to be installed in series. Also very important for the ducting to be sized correctly for the caddy. If you are serious about getting a caddy and ducting, then have them install the woodfurnace when they do the ductwork. Not every HVAC person will know how to install something like that. I'm 25 and I had to explain how my woodfurnace works with main furnace because they couldn't figure it out. When they seen my ductwork I installed, they offered me a job. It will be an excellent setup, but plan carefully and follow all manuals and you will be okay. Now I think the caddy comes from Canada???   But on page 25 of the installation manual it shows that the oil backup and the woodfurnace share the same flue. The oil flue is above the woodfurnace flue. I'm not sure about this setup, But thats what it shows. If thats the case then its 1 flue.


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## Beno

It looks that the equivalent of the Caddy is the Hotblast EPA model 1950. Yes, Caddy is produced in Canada (Quebec) and that means plenty of dealers in my area.
I will buy the Caddy with oil or electric backup, to have only one furnace. We plan to heat mainly with wood, so I am not sure if it's worth to go with oil (one flue). Now, I have a few questions:
1. What is special/different when you design the ductwork for a wood furnace? Just to respect the clearances, right?
2. I'd like to have a crawl space (5 ft height), where the furnace sits. Will be possible to take the hot air plenum through the crawl space ceiling and go from there with the ducts to the first and second floor?
3. What is the sq.ft. that you heat with the Hotblast ?
4. For how many years do you have the Hotblast and if you had any special problems?

Many thanks!


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## Gooserider

Beno, you need to download the Caddy manual, or the manual for whatever furnace you are planning to use and see what they say about using a single flue - that is the ruling document.   It may also have the answers to your questions about clearances and plenum design.

Also it may be worth considering some other points that  I've seen - I don't claim to be an expert, but I've seen multiple seperate mentions of these issues.
1. Many comments suggest that multi-fuel units often sacrifice performance with one (of both) fuels as it isn't really possible to design a firebox that is optimal for both.
2. I've also seen things suggesting that the oil burner "guns" in wood / oil units are very susceptible to damage when burning wood, unless they are removed, but removing the oil gun sacrifices the use of oil as backup when one unexpectedly looses the wood heat...
3. With a multi-fuel unit, you have a "single point of failure" heating system - if anything goes wrong, your entire heating system is out of commission.  W/ seperate units you have more redundancy.

This would all incline me more towards a dual unit setup (which would require dual flues)

Either way, if doing new construction, I'd consider it good "future proofing" to include two flues, or at least the space for them, in your design, as that would allow you or a future owner more options for changing things in the future without major hassles.

Gooserider


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## laynes69

I have an older model. They are still being produced today, they heat well but if you don't know how to burn them correctly can be a dirty burner. You cannot have any restrictions in pressure when you duct an add-on like this in. Everything that goose has concerns with is legit. I wouldn't want a single thing to go bad on me and lose my heat. And the thing with the clearance, the units are 4 feet tall. The unit will not fit in a crawl space. Have you personally seen them? They are large units. If you want to get the best setup get a oil furnace thats high efficiency and duct in the caddy. Dual flue and less problems for things to go wrong. I heat 2400 square feet with my furnace. That furnace is designed for 3000 square feet. Now if you install it correctly and have good tight construction then if planned wisely it should do okay. Heres the thing. The unit is designed for 3000 square feet. If you get the wood/oil combo, What if it couldn't keep you home warm? If it was me I would get a oil furnace sized correctly for the home and if you can install with full clearances then duct in the caddy. I'm afraid that installing something like this in a crawlspace could be a disaster. At a potential for 140,000 btus, do it right. If it wouldn't work for the home, then I wouldn't make it work.


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## Beno

I will install the Caddy on slab on grade, there will be no basement/crawl space. With correct design I hope the Caddy will do the job for an ICF passive solar house of 3600 sq.ft., with good insulation and windows. Instead of oil backup and/or additional oil furnace I prefer to go with the electric backup. I guess this is a safer approach for the Caddy, there will be one flue for the wood only. This will also save the space and the potential problems related to burning oil. 
If there will be not enogh heat I prefer to add a wood stove (I am serious about heating with wood ).
Now, I undertsand that the key of success in using a wood furnace (or a furnace in general) is a good ductwork design. I'll have to learn this area also.
Many thanks!


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## Gooserider

One of our former members, Elkimmeg, has made several posts in different areas of the board where he talks about ductwork and how it should be designed and built.  I would say that his posts on the subject are well worth reading, and I highly reccomend them as a starting point.

Gooserider


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## Beno

I am very sorry to hear that Elk is a former member of this forum. He gave lots of great advice.


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## eernest4

hi beno,

          You have 3000 sq ft so I think you should be buying the caddy model psg 4000
in hot air wood/oil.  You will find that electric will be equal to or greater in cost than oil.

Another reason to go with oil is that you can run both your duct blower motor and your oil burner 
frpm a 4000 or 5ooo watt 5 or 6 hp generator which usually costs around $500.oo

I bought one for myself back in 2000, never had to use it,but if i ever loose power, I will still have heat & a refrigerator & tv.

With the electric heater coil, loose power,, and well, your not going to run that off any generator with a engine smaller that 150 hp & 25,000 watt generator costing thousands of dollars.

         The model 4000 is designed to heat 4000 sq ft ,so you will have 400 sq ft extra capacity
to see you through the coldest nights.

         The becket oil burner is rated 84 % efficient and located beneth the wood furnace
ash box so that you dont have to worry about the wood fire damaging the oil burner.

         By the way, that becket oil burner is the same one i installed myself(DIY) in my hot water furnace back in 1985. 22 years later & it is still running like the day it was new.
It is one honney of a oil burner & very easy to service, as oil burners go.

Also, you can buy the caddy 4000 wood / oil hot air furnace with the acceptance hole for the becket oil burner without buying the becket oil burner & add the oil burner on at any time later.

      In a power outage, you run the oil burner or wood blower off the gasoline generator.
You can not cook on the hot air furnace ,it is not a wood cooking stove & I would not run the wood furnace during a power outage without hooking up the duct blower to the generator.

If all you are going to run is just the duck bkower & not the oil burner,you can get away with using the 1000 watt or 500 wt 1 hp 2 cycle chineese two cycle (mix oil in gasoline)generator that you see selling for $100.oo to $200.oo at www.harborfrieght.com, but this is a baby generator and can only power one thing at a time.

The duck work clearances are 6 inch for the first 6 ft and 2 inch thereafter.
29 inch clearances are needed around the furnace to leave room for the service man to crawl in and service stuff.

All this info(except about the generators) is on the link you provided. 
 I guess you were so excited that you just forgot to read it there.

Please do download the owners manuel and read it.It is there on that bottom link in your first post of this thread.

The duct fan can be wired either with a relay or with a 2 way hall way switch so that in one position the fan gets household power & in the other position,it is disconnected from household power and is fed from the generator feed wires.


I would not worry about the two chimney thing because they don't want two seperate heating appliances sharing the same chimney  AT THE SAME TIME BECAUSE IT DIVIDES THE DRAFT
IN TWO AND EACH UNIT ONLY GETS HALF THE DRAFT IT NEEDS.

THAT IS NOT THE CASE HERE. You either fire the wood side or the oil side but never both sides at once, so you never have two heating appliances sharing the same draft at the same time and cutting the draft in half.

The unit is designed to opperate from one chimney, either  designed into  a common firebox or with a cut out plate/baffle, that cuts off the firebox not in use from the draft, in the case of two fireboxes.

It is sure one sweet setup & if it were me, I wouldn't hesitate for one second in buying one.


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## Beno

Thanks for the feedback and explanations about the dual wood/oil. Very usefull. 
Do you know if I can use the same oil tank for both oil furnace and an oil water boiler for DHW?
Would you recommend upgrading from Becket to a Riello burner?
Would you recommend using an oil water boiler with direct vent, like Kerr Comet? (To save the money for the flue/chimney).
Sorry for so many questions but it's a complex problem with multiple solutions. 

Option1: oil water boiler and wood/oil Caddy furnace
Option2: solar/electric (DHW) and wood/electric (Caddy). 

These are my 2 main options I need to choose from, for heating and DHW.

Thanks again,
Beno


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## BrownianHeatingTech

Beno said:
			
		

> Do you know if I can use the same oil tank for both oil furnace and an oil water boiler for DHW?



Yes.  In fact, you would not want two tanks, as the oil in the "furnace only" tank would sit unused for long periods, developing sludge.



			
				Beno said:
			
		

> Would you recommend upgrading from Becket to a Riello burner?



Riello is the best oil burner available in the US, right now.  Some folks complain about the repair parts being more expensive, but there's a very good reason for that - suppliers and service companies have to invest in those parts, which sit on shelves for long periods, rather than being used and bringing in profit.

Do yourself a favor, and make sure that the oil burner has an outside air intake (eg, Riello BF-series), so you aren't burning indoor air that you paid to heat, and creating draft problems by sucking air out of the room.

Also, make sure that the oil tank has a spin-on filter, rather than the "felt" cartridge filter that some installers still use.  The felt filters can actually release fine fibers which will damage the oil pump (particularly the oil valve).



			
				Beno said:
			
		

> Would you recommend using an oil water boiler with direct vent, like Kerr Comet? (To save the money for the flue/chimney).



A second flue would be preferred, as natural-draft appliances are more reliable.  However, a proper sidewall-venting boiler would certainly save money.  Just be aware that not all sidewall venting systems are created equal.  I can't say that I'm the biggest fan of Kerr, personally, but that's in-part because no one around here really keeps parts in stock for them, so when something does break it's not a quick fix.

If you are going to have an oil boiler (ie, not a water heater), it probably makes the most sense to skip having a second oil burner in the furnace, and use a water/air heat exchanger on top of the furnace.  It works essentially the same as an automotive radiator - the oil boiler circulates hot water through the finned pipes, and the furnace fan blows the air over it.

If you don't have a need for an oil boiler, because you will be using the oil burner option in a wood/oil furnace, then you may want to look into a tankless (on-demand) water heater.  There are a lot of gas ones, and some oil ones as well.

Joe Brown
Brownian Heating Technology
www.brownianheating.com


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## Beno

Joe, I noticed on your web site that you supply/install also solar systems for DHW.
What do you recommend?
Option1: oil water boiler and wood/oil Caddy furnace 
Option2: solar/electric (DHW) and wood/electric (Caddy). 

Thanks!


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## BrownianHeatingTech

Beno said:
			
		

> Joe, I noticed on your web site that you supply/install also solar systems for DHW.
> What do you recommend?
> Option1: oil water boiler and wood/oil Caddy furnace
> Option2: solar/electric (DHW) and wood/electric (Caddy).



I wouldn't use either of those options, honestly.  A boiler just for hot water is excessive.  And I don't install electric water heaters - the operation cost is just way too high.

I would suggest a wood/oil furnace, and a solar storage tank that is used to pre-heat water which supplies a tankless water heater.

Joe


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## Beno

Are also the electric tankless water heater expensive to operate? (We will have only oil and electricity in the new location)
It seems that most tankless water heater are either electric or gas. I managed to find this one, oil fired:
Toyotomi OM-180 Oil-Fired Tankless Water Heater
Doesn't come cheap, the price is about the same as a tankless oil boiler.


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## BrownianHeatingTech

Beno said:
			
		

> Are also the electric tankless water heater expensive to operate? (We will have only oil and electricity in the new location)



They are not my preference, but they are certainly less expensive than keeping a tank hot with electricity.



			
				Beno said:
			
		

> It seems that most tankless water heater are either electric or gas. I managed to find this one, oil fired:
> Toyotomi OM-180 Oil-Fired Tankless Water Heater
> Doesn't come cheap, the price is about the same as a tankless oil boiler.



A tankless oil boiler works by keeping the boiler hot all year long.  So, that's ~500 pounds of cast iron and water that you need to heat, even during the summer.  The efficiency of doing that is very low.

Joe


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## Stove Geek

Just to bring some light into this:

SBI is the maker of the Caddy EPA CERTIFIED furnace. The first in the world. It is not Exempt. It is a non-catalytic firebox. It can be used with the combination with Oil or Electricity. It can also be used as an Add-on to oil, LP and GAS. 
US Stove does not stock this furnace. They had one made under private label in 2005 but they have discontinued it.
The Caddy is not the regular wood furnace. It is a High-Efficiency appliance that needs t be installed by a professional. The Dusctwork needs to be pressurized properly and the venting needs to be regulated.
The Caddy has been on the market in Canada since 2002. It is now the best-selling combination furnace in Canada. Great product! Heavy built, all pannels are zinc-coated...there's nothing like it!


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## Eric Johnson

Thanks for the clarification, Stove Geek. I like the idea of a clean-burning furnace (don't know why more aren't) and especially the glass door.


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## laynes69

Usstove does produce furnaces just like these. I have seen them personally and they are well built units. We have a local place that I can drive to and buy the Usstove 1950 model. Either way they seem like they would produce alot of clean heat for larger homes.


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## Stove Geek

US Stove had the Hot Blast 1950 built by SBI in 2005. They have since discontinued the unit. They may have some in stock still.


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## derbygreg

Finally found the homepage for the caddy furnaces.  

http://www.psg-distribution.com/products.aspx?CategoId=16


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## Beno

There is also the mini Caddy, which is said to be also EPA, but In House Tested. I wonder how reliable is this EPA In House Tested and what does it mean? The mini Caddy is not on the EPA list as Caddy: Caddy (duct furnace) Noncatalytic 6.6 63 % 12000-52900 3/19/2008.
For me, the Caddy would've been perfect with a coil for DHW, to heat water.


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## Stove Geek

The Mini-Caddy is EPA approved by Warnock Hersey since the fall of 2006...


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## Beno

What I wonder now is what will be a good system for DHW, aside by Caddy wood/oil?
I like the Tarm - Excel2000, the wood boiler with oil backup that can supply hot water for both heating and DHW, including during the Summer. One of the major issues I have with the Tarm is that it requires a large water tank, for heat storage. My question is: how do you enter the huge tank in the house, through the door? Or is it assembled in the house?


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## Eric Johnson

The tanks come unassembled, so they're relatively easy to ship and move into your house. My understanding is that they're pretty easy to set up. It's really just some sheets of aluminum, a rubber pond liner and some foam insulation.

Heat storage is not required, but it is a nice feature. You can install the boiler and see how it works in your situation without storage, and then add the tank later.


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## Beno

Thanks Eric. If there is no tank, where does all the heat goes when is not needed? How much could the tank cost, and its size? Why did you go with EKO and not Tarm? How reliable are these systems? 
Ideally, when the heat is not needed the wood boiler will send the heat in the house instead of chimney.


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## Eric Johnson

I can't comment on the Tarm because I've never seen one operate. What the EKO does is go into "idle" mode, where the blower (or blowers) shuts off  and gasification basically stops. The heat doesn't go up the chimney. You can get a little bit of smoke out of the chimney when this happens, but the boiler doesn't overheat. The EKO's controller starts up the blower every 10 minutes or so for a few seconds to keep the coals alive. When the call for heat gets the boiler temp back down below the setpoint, the blower comes back on and gasification resumes.

You can get different size tanks. They're not cheap. Many people build their own. The heat exchangers, usually copper coils, are also very expensive with today's high copper prices.

I went with the EKO mainly because it will take wood over 24 inches long, and all my wood is about that length. The Tarm 60, as I recall, takes a maximum length of 20 inches. I didn't want to spend my first winter cutting down my firewood, and my whole setup is pretty much geared to the 24-inch wood anyway. I've been running my boiler 24/7 for a couple of months and it's been very reliable so far. There aren't many moving parts, so that ain't that much that can go wrong. I believe the Tarm has a 20-year warranty. The EKO's is 5 years. Both look like they're going to be around for awhile.

I'm talking here about gasification boilers. Tarm also sells some conventional wood boilers, and very little that I've said applies to them. Generally, however, a conventional wood boiler is easier to use than a gasifier, and hot water storage is even less of a priority. The trade-off is that they burn more wood and produce smoke. A properly-operating gasifier works with no visible smoke.


----------



## Stove Geek

PSG is putting a new Extra Large Caddy on the market in 2009 and it will have the hot water coil option. That furnace will meet the canadian EPA standard, CSA B-415. It will not be a boiler, but it will heat up water for the hot water tank. That furnace will have the optional combinations to oil and electric and will be available as an add-on as well...should be on the market in the fall of 2008.


----------



## Beno

That's great news! Was there any public announcement about this plan? How do you know about it? If I buy the Caddy today, will I be able to add the coil later?

Eric, how much did you pay for the EKO and how much for the tank? I am concerned also with the complex plumbing that heating with water requires. Water is corrosive + sediments of minerals ...


----------



## Stove Geek

I know, I work there....

Today's Caddy cannot accept the water coil...it will be introduced after the Caddy XL is on the market. Sorry...


----------



## Beno

Will the Caddy XL be EPA approved too? Will the Caddy XL be able to provide hot water also in the summer? Will this require a water tank for heat storage? How much hot water will this supply? Can we see a beta/draft specification of the Caddy XL spec?


----------



## Eric Johnson

Beno said:
			
		

> That's great news! Was there any public announcement about this plan? How do you know about it? If I buy the Caddy today, will I be able to add the coil later?
> 
> Eric, how much did you pay for the EKO and how much for the tank? I am concerned also with the complex plumbing that heating with water requires. Water is corrosive + sediments of minerals ...



You can get the current pricing for the EKO line at http://www.cozyheat.net. I'm only providing that link because it's the only place I know of that posts the prices. There are other dealers selling EKOs around the country.

I cobbled my tank up from an old concrete cistern in my basement. And I'm about finished building my heat exchanger, which is made of rigid copper. If you bought them retail, a 1,000 gallon tank and heat exchanger would probably set you back around $5,000. Maybe more. I have a lot of hours, but only about $1,000 in mine.

And yes, getting everything piped up involves extra expense and time.


----------



## Stove Geek

For the Caddy XL, it will meet the Canadian EPA standard, because it has a clause for large furnaces. The way the US EPA method is setup, it makes it impossible for very large fireboxes to pass EPA. The US method has a calculation for burn time that would require the Caddy XL to burn one load of wood for over 20 hours...without a single trace of smoke...we all know that's impossible. But I can tell you it will have very low emissions, no smoke. It will require a hot water tank for storage, no option there....for the specs, the draft will be available to the public in the summer of 2008. It will be th very best furnace produced by PSG to date.


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## Beno

Stove Geek, I feel so lucky I am able to get this info. Thanks!
The Caddy has a firebox of about 3.5 cu.ft. What will be the firebox cu.ft. of the newer Caddy XL?
Caddy *did *pass the US EPA tests, correct?

I might not be able to wait for the Caddy XL, we will build in spring - summer, and also we may not have the room for a large water tank (we have no basement because of high water table). I am sure though that other people will find this info very valuable.

Stove Geek and Eric, if I go with Caddy wood/oil furnace, what will be a smart solution for DHW?


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## Stove Geek

The Caddy did pass US EPA - the first in the world!

For the hot water, go tankless...that is the most efficient way - to my opinion.


----------



## Eric Johnson

If you can put a coil in the furnace, then you would be ahead, in my opinion, to circulate water between the coil and a conventional water heater. You'll have free hot water. But I would only do that with a coil designed for that furnace and preferably factory installed. It can be dangerous if not set up right.


----------



## Beno

This will probably make me loose the warranty on Caddy, and maybe even house insurance problems. What do you think about Eric's idea, Stove Geek?


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## Stove Geek

To keep your warranty, you should put your water coil over top the furnace, inside the warm air plenum...keep it outside the furnace cabinet...


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## micah

I have a concern about the one with the oil backup. I have been told NEVER to vent 2 things in the same flue. So does this require a second flue, one for each? Or is it that you cant RUN 2 things at the same time that are vented through the same flue?


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## Beno

They don't run at the same time.


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## Eric Johnson

The only time you are allowed to vent two different appliances into the same flue is if they are a combined unit. In some cases, you have no other choice, since both sides sometimes use the same exhaust outlet. It's not the smartest thing you can do, but it's within code. You can even run them at the same time. When it comes to two separate appliances, however, you are correct.


----------



## Stove Geek

The code says to run one appliance per chimney - The Caddy is one appliance that is approved as a combination furnace...it works great.


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## micah

[DELETED] You guys post to fast.


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## Eric Johnson

No. Like I said, separate appliances require a separate flue. You might get away with venting a gas hot water heater into the same flue as a gas boiler or furnace. That's how mine was hooked up before I switched to electric HW.


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## micah

Thats how mine is to Water heater and furnace use the same flue. Ill be switching to electric water in the spring.


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## Beno

Stove Geek, can I use the same flue used by Caddy wood/oil also for an oil hot water heater? The oil hot water heater can go with either direct vent or a flue. If possible I'd use one flue for the Caddy and the oil hot water heater.


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## Stove Geek

For new installs, it is one appliance per flue...so the hot water tank cannot be vented in the same flue as the Caddy...


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## BrownianHeatingTech

Okay, two things...

A lot of this is determined by code, and not all locations use the same code, so _caveat emptor_, and check with your local code enforcement.  Do _not_ ask them if you can do it.  Many local code officers are helplessly ignorant (not all, or even most, but far too many).  Ask, "can you get me a photocopy of the code that describes when multiple appliances can and cannot be vented in the same flue, so I have it for my records."  That makes them actually look up the code, rather than just giving you whatever answer comes to mind first.

Second thing.  Typical codes allow multiple appliances per flue, even on new construction, if they are oil or gas appliances.  What they do not allow is solid-fuel and liquid/gas-fuel appliances to share a flue.  They are separate critters, and shouldn't.  The typical rule for oil/gas appliances is that they may not enter the same flue at the same height, unless they are pre-connected in the flue pipe, before it meets the chimney (in which case there are rules about how that is done).

Exceptions are made for combination appliances.  But a separate oil-fired appliance cannot share a flue with a wood/oil combination unit.

The reasons are possible flue gas spillage (CO poisoning), and getting cinders into a oil or gas appliance.  I replaced a boiler a while back, which shared a flue with a woodstove.  The woodstove was on the first floor, and the boiler in the basement.  The boiler was half-plugged with cinders from the woodstove.

Incidentally, the woodstove hadn't been run in three years, and they'd been paying for yearly boiler cleanings, which kind of proved that the company they'd been paying to clean the boiler had been slacking severely.  And it was a separate tech each year, so it wasn't just one guy who was a slacker.

By the way, I'm not giving anyone legal advice here.  As I said, check your local codes.  Local codes can be more restrictive than state-level codes, and some are downright wacky.  The above information is simply what I've dealt with most commonly, as best I can phrase it.

Joe


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## Stove Geek

We're on the same page...
The Combination furnaces are considered as being one appliance although have two fireboxes...


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## mtnxtreme

Im also building a new home in the spring, but with a lot of sweat equity, so heat won't be needed till spring 09 probably. I was first considering Tarm or AHS wood/oil unit, to be used with a  hot water radiant floor system, they are priced rather high $6-8000. I see you guys talking abt. this Caddy unit for $2500, do they have a comparable unit to the Tarm or AHS. Whats the pros/cons. How long will it take me to see a return on my investment, I can buy a comparable sized oil only unit for like $1500. Looking for ideas.


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## Gooserider

mtnxtreme said:
			
		

> Im also building a new home in the spring, but with a lot of sweat equity, so heat won't be needed till spring 09 probably. I was first considering Tarm or AHS wood/oil unit, to be used with a  hot water radiant floor system, they are priced rather high $6-8000. I see you guys talking abt. this Caddy unit for $2500, do they have a comparable unit to the Tarm or AHS. Whats the pros/cons. How long will it take me to see a return on my investment, I can buy a comparable sized oil only unit for like $1500. Looking for ideas.



Could be wrong, but I believe the Caddy unit is a forced hot air furnace, while the Tarms, EKO, etc. are forced hot WATER boilers.  So you are looking at totally different heating methods.  In general, HVAC setups are less expensive, boilers much more expensive, but do a better job of heating / more comfortable / quieter / cleaner...  Also boilers seem to last longer if properly taken care of.

Gooserider


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## Eric Johnson

Goose is right.


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## BrownianHeatingTech

Furnaces typically have 30-50% shorter lives than boilers (depending on the particular boiler and particular furnace, obviously).  They also consume dramatically more electrical power, which can be a concern in terms of cost, or in terms of running on backup (batteries/solar/generator) power.

Joe


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## Beno

I think we need to compare here the systems and not the elements.
Around the boiler you have lots of plumbing, and things may break there. The air ducts will not make problems (if you keep changing filters on time). Also, with hydronic heating you need to supply ventilation (ERV/HRV, some smaller air ducts), and you don't have air conditioning in the summer. Also, it is recommended to have large/expensive water tanks for heat storage.
If you don't have a boiler, the DHW may be supplied with an oil heater and eventually solar.


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## BrownianHeatingTech

Beno said:
			
		

> I think we need to compare here the systems and not the elements.
> Around the boiler you have lots of plumbing, and things may break there. The air ducts will not make problems (if you keep changing filters on time). Also, with hydronic heating you need to supply ventilation (ERV/HRV, some smaller air ducts), and you don't have air conditioning in the summer. Also, it is recommended to have large/expensive water tanks for heat storage.
> If you don't have a boiler, the DHW may be supplied with an oil heater and eventually solar.



If you would need ventilation with your hydronic system, you would need it with a forced-air system.  The need for ventilation relates to the tightness of the structure, not the heat-delivery system.

Air ducts are a breeding ground for all manner of nasties.  Open up an older air system, and you won't like what it looks like inside there.  Not that it will necessarily be bad, but it can get there way too easily if the conditions are right.

You only need heat storage tanks with gasifiers.  A "disadvantage," to be sure, but since the furnaces don't have the option of being gasifiers, let's compare conventional (non-gasification) wood boilers to the non-gasification furnaces...

The lack of air conditioning is about the only drawback, and that can be remedied with ductless mini-splits (Fujitsu happens to be my favorite), while using a lot less energy than most central A/C systems.

Joe


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## Beno

1. Based on the code in my area, I need ventilation to each room if I don't have a furnace with air ducts. If I have a furnace, the ventilation will be done by the furnace fan to the rooms, and I'll have to supply outside air to the furnace. So, even with hydronic heating I need to install ducts (smaller) for ventilation. Cleaning them may be harder than with the furnace ducts.

2. I thought that the wood boiler comparing in efficiency with a Caddy EPA wood furnace has to be a gasification boiler. Can you please recommend a very efficient (non-gasification) wood boiler?


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## Jim Post

I'm happy to report that gasifiers don't NEED storage....it's nice, but c'mon you can achieve a clean burn w/o storage...it just requires you to think a little bit when loading....similar to how you would tend a wood stove.  It works for us anyway.


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## Eric Johnson

The Caddy specs on the combination unit are 73 percent efficient with wood and 82 percent with oil. That's not bad for the wood side and while 82% is pretty average for an oil burner, it's a good number for a combination unit.

Gasifiers tend to claim high 80s to very low 90s in overall efficiency.

Tarm's Excel 2000 is a combination oil/conventional wood-fired boiler. They claim 80% on the wood side and 85-87 with the oil. New Horizon also has a selection of conventional boilers, as does Marathon.


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## Beno

How can you supply DHW w/o storage?


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## Eric Johnson

That's true about clean burning without storage and the firing strategy being similar to a wood stove or furnace. I think what you sacrifice without storage is efficiency, because if you produce heat at the wrong time, it tends to get wasted. A good firing strategy helps keep that to a minimum. Gasifiers with storage are also supposed to last longer, though I'm not completely clear on why.

If you put a heat exchanger on a conventional hot water heater and pump hot water from the wood boiler through it, Beno, it will fill your water heater tank with hot water and keep it that way. That's what I've done for the past 15 years, and we never run out of hot water.

Where the tank comes in handy for DHW is in the summer because you can fire your boiler up once a week, heat the tank, and live off that.


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## Jim Post

I have a sidearm heat exchanger on my electric water heater....provides an endless supply of hot water.


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## BrownianHeatingTech

Beno said:
			
		

> 1. Based on the code in my area, I need ventilation to each room if I don't have a furnace with air ducts. If I have a furnace, the ventilation will be done by the furnace fan to the rooms, and I'll have to supply outside air to the furnace. So, even with hydronic heating I need to install ducts (smaller) for ventilation. Cleaning them may be harder than with the furnace ducts.



I'd like to read the actual code on that.



			
				Beno said:
			
		

> 2. I thought that the wood boiler comparing in efficiency with a Caddy EPA wood furnace has to be a gasification boiler. Can you please recommend a very efficient (non-gasification) wood boiler?



Biasi.

I expect there are plenty more that can meet the Caddy's efficiency, with ease.

Joe


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## Jim Post

In the summer,  I revert to electric....but I am thinking with a little scheduling we could fire the tarm for our hot water needs.  :bug:


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## Eric Johnson

I have a sidearm, too, JP. They're easy to build and pretty much bullet proof.

I don't know if yours feeds through gravity but if it does, you might want to consider putting a circulator on it for summertime heat stashing. I doubt the gravity feed (which is the way mine is set up) can transfer heat fast enough to keep up with the boiler. Maybe add another/bigger tank or an indirect. That way you could probably stash enough HW for a couple of days with one firing.


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## Beno

9.32.3.7.  Ventilation Systems Not Coupled with Forced Air Heating Systems
    (1)  This Article applies to a mechanical ventilation system in a dwelling unit that,
    (a)    does not contains a forced air heating system, or
    (b)    contains a forced air heating system and the forced air heating system is not used for circulation of the ventilation air.
    (2)  The mechanical ventilation system shall introduce air to and circulate air throughout the dwelling unit in compliance with this Article.
    (3)  The mechanical system in this Article shall include a heat recovery ventilator installed in accordance with Article 9.32.3.11.
    (4)  Outdoor air shall be distributed by a ductwork system from the heat recovery ventilator required in Sentence (3) to each bedroom, to any storey without a bedroom and, if there is no storey without a bedroom, to the principal living area.

This is for Ontario, Canada.


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## Jim Post

Ok....I have to consider that...I've never fired the tarm in the summer so that would present a whole new set of operating issues.


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## Beno

1. Can you please recommend an efficient wood boiler for my location: Ontario, Canada ?

2. Can I use instead of the large water tank an indirect like this?
http://www.heatexchangersonline.com/indirectwaterheater.htm
http://www.thermomax.com/tkindex.htm


----------



## BrownianHeatingTech

Beno said:
			
		

> 9.32.3.7.  Ventilation Systems Not Coupled with Forced Air Heating Systems
> (1)  This Article applies to a mechanical ventilation system in a dwelling unit that,
> (a)    does not contains a forced air heating system, or
> (b)    contains a forced air heating system and the forced air heating system is not used for circulation of the ventilation air.
> (2)  The mechanical ventilation system shall introduce air to and circulate air throughout the dwelling unit in compliance with this Article.
> (3)  The mechanical system in this Article shall include a heat recovery ventilator installed in accordance with Article 9.32.3.11.
> (4)  Outdoor air shall be distributed by a ductwork system from the heat recovery ventilator required in Sentence (3) to each bedroom, to any storey without a bedroom and, if there is no storey without a bedroom, to the principal living area.
> 
> This is for Ontario, Canada.



That's not every room.



			
				Beno said:
			
		

> 1. Can you please recommend an efficient wood boiler for my location: Ontario, Canada ?



Need a lot more information than a geographical location.  What will it be heating?



			
				Beno said:
			
		

> 2. Can I use instead of the large water tank an indirect like this?
> http://www.heatexchangersonline.com/indirectwaterheater.htm
> http://www.thermomax.com/tkindex.htm



Yup.  The larger the storage, the better, but there's no particular minimum.

Joe


----------



## mtnxtreme

Thanks, so the basis for the extra cost of a boiler versus a Caddy HVAC is the greater efficiency and longer life. I definetely wanted HW, I have ducts now, and the HVAC drived my allergies crazy. So for boilers, are Tarms the ticket compared to AHS etc, who's got the best deal for the money?


----------



## Eric Johnson

When I bought my boiler, about six months ago, the EKO had the best price. But like the Tarm, it's an import, so the weakening dollar has driven up prices recently. For regular gasifiers (Tarm, EKO, Wood Gun, Econoburn), I'd be willing to bet that Wood Gun is still at the high end and EKO at the low end, with Tarm and Econoburn probably pretty close to each other in the center. Just a guess. As to true value, everybody's got an opinion, many of which are regularly expressed in threads on this forum.

EDIT: I forgot the BioMax, another import. I believe they're a bit cheaper than EKOs, possibly with more features.


----------



## Beno

We are in the design phase, so we consider different options. I'd like to have a wood based solution with oil backup. I chose the Caddy wood/oil because there are many dealers for Caddy in my area. This will be a 2 storey house, ICF walls, energy efficient, passive solar, 3600 sq.ft. Here are the options I see now:
1. Caddy wood/oil for heating + oil heater for DHW.
2. Caddy wood/oil for heating + smaller wood/oil boiler for DHW.
3. Wood/oil boiler for heating and DHW

The house will have no basement, so not much storage room. Your advice is greatly appreciated.


----------



## Eric Johnson

You seem committed to the Caddy, but personally, I'd go with hydronic heat in a heartbeat. It's such a superior way to heat your house and hot water than forced air, and it has virtually unlimited potential for expansion and modification down the line. You can mate solar up to hydronic heat easily, and probably geothermal for all I know. Pumps are a lot more efficient than blowers, and your options with water are so much more plentiful. You can go with infloor radiant, cast iron radiators, hot water baseboards (copper fin tube and cast iron), etc. The list goes on and on. Looking forward into an uncertain energy supply and price scenario, I think you're way ahead with the efficiency, convenience and economy of hydronic heat.

I'd get a bare-bones oil burner and a good gasifier and be done with it. Design a place for a tank, whether you put one in right away or not. The big problem with combination boilers, in my opinion, is that if they spring a leak, you're suddenly out of options. Plus, no matter what the mfg claims, you're always going to make compromises on one side or the other--or both--with a combo.

This would all cost more, obviously, but if you think of it like choosing the insulation for your new house, it's basically the same decision: Pay more up front for longterm savings and comfort.


----------



## Beno

I agree with you Eric, in fact this was my original plan. The only thing that made me change my mind from wood boiler was the lack of dealers/support for indoor efficient wood boilers in the area where I live, Ottawa, Canada. I have no explanation for this. The Caddy is made in Quebec, not far from us.


----------



## Eric Johnson

I'm sure there are plenty of competent heating contractors in Ottawa who could fix 95% of anything that could possibly need attention. As far as maintenance on a gasifier, there's really not much to them. No moving parts other than the blower, which can be replaced with about four screws and a couple of wire nuts. Any reasonably handy person can do all the maintenance and repairs that don't require welding. So I wouldn't let that weigh too heavily in your decision.

But it sounds like fun. Good luck with whatever you decide to do and let us know how it works out.


----------



## mtnxtreme

Eric Johnson said:
			
		

> When I bought my boiler, about six months ago, the EKO had the best price. But like the Tarm, it's an import, so the weakening dollar has driven up prices recently. For regular gasifiers (Tarm, EKO, Wood Gun, Econoburn), I'd be willing to bet that Wood Gun is still at the high end and EKO at the low end, with Tarm and Econoburn probably pretty close to each other in the center. Just a guess. As to true value, everybody's got an opinion, many of which are regularly expressed in threads on this forum.
> 
> EDIT: I forgot the BioMax, another import. I believe they're a bit cheaper than EKOs, possibly with more features.



      I can't find a dealer or pricing , for the biomax, got a link?


----------



## Eric Johnson

This is the only place I know of:

http://www.newhorizoncorp.com


----------



## Beno

Eric, great support work, I really appreciate it. I'll start to look seriously into the Tarm.


----------



## mtnxtreme

So the Biomax and EKO are wood only. I'm interested in wood/oil combo units. So I'm limited to Tarm and AHS?


----------



## Eric Johnson

For gasifiers, it looks that way. There are plenty of non-gasifying wood/oil/gas combos on the market. I'm not sure if Econoburn offers a combo model.


----------



## Beno

Will one indirect be enough for the TARM to supply both DHW and hydronic heating? The DHW and hydronic heating must have different loops, will I need 2 indirect water heaters for that? I try to figure out how the piping will go. Or maybe the water heated by TARM directly in its jacket will be used for hydronic heating and the indirect is used only for DHW? Thanks!


----------



## Eric Johnson

I'm a little confused. Typically, the indirect is one zone (or loop) on the system, among others. But it doesn't have to be. You could run everything through the indirect's heat exchanger before sending it into the house zones if you like, or put in a three-way zone valve to direct the flow of water where it's needed. For DHW, all you would need is one indirect. If you are planning to install another one to serve as hot water storage, it's not going to be much of a benefit, because there isn't that much capacity in most indirects. But just for the sake of discussion, if you did that, there are a number of different piping strategies that you could use, depending on your needs.

That's one great thing about hydronic heat--you can do a lot of different things with it--often simultaneously.


----------



## BrownianHeatingTech

Beno said:
			
		

> Will one indirect be enough for the TARM to supply both DHW and hydronic heating? The DHW and hydronic heating must have different loops, will I need 2 indirect water heaters for that? I try to figure out how the piping will go. Or maybe the water heated by TARM directly in its jacket will be used for hydronic heating and the indirect is used only for DHW? Thanks!



If you're using an indirect for a "buffer" on the heating system, you can use it for both.  The heat exchanger can put heat into it, but it can also take heat out of it.

You can also add a small amount of pressurized storage by using an electric hot water tank, and just not connecting the power to it.  Instant pressure-capable tank.

Joe


----------



## mtnxtreme

Eric Johnson said:
			
		

> For gasifiers, it looks that way. There are plenty of non-gasifying wood/oil/gas combos on the market. I'm not sure if Econoburn offers a combo model.



     Eric, Are gasifiers worth the extra expense over non gasifying, I see Tarm and AHS offer both ways. I also see ou are a fan of separste units versus combo?


----------



## Eric Johnson

Since I bought one, I obviously think they're worth the extra expense. In my idea of a perfect world, everyone would buy a gasifier. However, the world ain't perfect and your circumstances might call for something different. The advantages of gasifiers are as follows:

Half the wood consumption
Little to no smoke

The disadvantages:

Higher cost
Require dry wood

I'd say that if you have a large amount of cheap or free wood at your disposal (into the foreseeable future) and you don't care about smoke (and don't plan to), then an OWB might not be a bad choice. 

As to separate vs. combination oil/gas and wood, my main complaint is that you're putting all your eggs in one basket. A leaky boiler means no heat until you replace it. If you have a dedicated boiler for each fuel, then you can easily switch back and forth as needed, and be sure that each one is burning its fuel efficiently. A combination arrangement always involves a compromise. And, if you were able to find a wood/oil combination that manages to burn both efficiently without compromise, then it's probably going to cost more than having one of each. And you're still in the same (sinking) boat if the thing springs a leak.

If it happens during the heating season (when else?), you don't have the luxury of shopping around and thinking about your options. About your only option is to replace immediately--either with more of the same or a dedicated unit of some sort.


----------



## BrownianHeatingTech

mtnxtreme said:
			
		

> I also see ou are a fan of separste units versus combo?



As Eric said, redundancy is a good thing.  Two boilers are better than one.  It doesn't even have to be as big an issue as a leak.  There are simple problems which might render one boiler inoperative until repair parts are installed.  Do you want to call a service company on a weekend, paying a premium for emergency service, or just schedule the repair at a convenient time?

Wood heat exchangers are different than oil/gas heat exchangers.  The solid fuel heat exchanger sacrifices a certain level of efficiency for wider passages that are less likely to plug up... the oil or gas heat exchanger can be designed for better efficiency.

Also, you don't want to know what happens when a decent-sized cinder wedges itself into an oil burner's end cone...  You really don't want solid fuel and oil/gas venting up the same flue, on general principle.

Put up a second flue and sit an HB Smith or a Crown (or other decent quality oil boiler - doesn't need to be fancy) next to the wood boiler.  It costs a bit more, now, but it is more efficient, more reliable, and safer.

Joe


----------



## Beno

This thread became something very interesting and useful, more like Caddy EPA wood furnace vs Gasification wood boilers.
I have 2 questions:
1. With separate wood oil boilers, can you keep the oil boiler off and start it whenever you want or it must work in parallel with the wood boiler, as a backup whenever the water temparature is lower than a threshold? I'd like to have the full control of when the oil boiler kicks in (w/o damaging the oil boiler).

2. I agree that hydronic heating provides a better comfort, and is healthier. What I need to find out is at what price. Let's take a 2 storey house having 3600 sq.ft.
With Caddy wood/oil + Oil heater + Solar panels DHW + Air ducts = $5000 + $2000 + $5000 + $4000 = $16000.
With TARM wood + Oil boiler + HRV/ERV ventilation + Radiant heating (in floor or panels) = $8000 + $2000 + $2000 + $10000 = $22000.

I didn't add here the indirect water heater, which I assume is needed for either solar or wood boiler. I am not sure if the numbers are correct, so please feel free to correct me. Will the hydronic heating be at least 30-40% more expensive ?

Thanks!


----------



## Eric Johnson

I can only comment on the boiler question. I have a gas boiler as a backup, and I shut it down when the wood is running, which is to say October through May. There's no reason to leave it on, and I don't ever want to be burning gas, so the best solution is just to flip the switch. For me, "backup" means it operates at my discretion. And that's without the benefit of a storage tank, at the moment.


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## BrownianHeatingTech

Beno said:
			
		

> 1. With separate wood oil boilers, can you keep the oil boiler off and start it whenever you want or it must work in parallel with the wood boiler, as a backup whenever the water temparature is lower than a threshold? I'd like to have the full control of when the oil boiler kicks in (w/o damaging the oil boiler).



Yes.  A simple switch will do it.  If you want to get fancy, you can install a second thermostat (they even have non-adjustable ones) set to 50F or whatever, and use it to over-ride that switch.  So, with the switch "on," the oil operates whenever the wood isn't running, based on water temp.  With the switch "off," the oil won't operate, unless the house gets down to 50F, thereby protecting your house if you left in a hurry and forgot to switch the oil back on (eg, emergency trip to hospital).



			
				Beno said:
			
		

> 2. I agree that hydronic heating provides a better comfort, and is healthier. What I need to find out is at what price. Let's take a 2 storey house having 3600 sq.ft.
> With Caddy wood/oil + Oil heater + Solar panels DHW + Air ducts = $5000 + $2000 + $5000 + $4000 = $16000.
> With TARM wood + Oil boiler + HRV/ERV ventilation + Radiant heating (in floor or panels) = $8000 + $2000 + $2000 + $10000 = $22000.
> 
> I didn't add here the indirect water heater, which I assume is needed for either solar or wood boiler. I am not sure if the numbers are correct, so please feel free to correct me. Will the hydronic heating be at least 30-40% more expensive ?



The numbers will depend on your local market in some cases.  I think the 30-40% is a fair general estimate.

Joe


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## bbb123

I have a Tarm solo 45, this is my 3rd winter.  I suggest hot water (I have baseboard) if you can go radiant you will never be unhappy with it.  I've never felt warm in any hot air heated homes.  I also have the Mitsubishi slim line series heat pumps for air conditioning, they work very nice also.


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## Beno

Are you using the Tarm also for DHW ? I'll go to the expense of hydronic heating only if it can also assure year round hot water. Do you use the same 800 gal storage tank to supply hot water or you have an indirect for this?


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## bbb123

I get my DHW from storage tank.  It takes 5-7 days in summer between fires I wait till tank goes to 120 then reheat to around 160.


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## Beno

I wonder if I can use the Caddy to preheat DHW with an air to water heat exchanger, like this one for example: http://www.heatexchangersonline.com/airtowater.htm .
Maybe using a special duct connected to the hot air plenum that I manually open for air to water heat exchanger when is warm enough in the house.


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## laynes69

It wouldn't work. Those are for boilers.


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## Beno

I have a question about air conditioning. If I have the Caddy with electric backup, do I need anything else to connect to the Caddy, except of course the outdoor central air conditioning system? I've seen some systems that require an indoor coil/element to be connected to the furnace, and I wonder how will this work with Caddy? Many thanks, Beno.


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## BrownianHeatingTech

Beno said:
			
		

> I have a question about air conditioning. If I have the Caddy with electric backup, do I need anything else to connect to the Caddy, except of course the outdoor central air conditioning system? I've seen some systems that require an indoor coil/element to be connected to the furnace, and I wonder how will this work with Caddy? Many thanks, Beno.



A standard split system will always have an outdoor condensing unit, and an indoor evaporator coil.  The evaporator coil absorbs heat from the air, boiling the liquid refrigerant.  The refrigerant vapor goes outside to the condensing unit where it is compressed back to liquid and dumps the heat to the outdoors.  The liquid then travels back to the evaporator coil, in a continuous cycle.

"Packaged" units put both coils in one box, meaning you run ductwork outside the house to the evaporator coil, then back in.  It's a bad idea in most climates.

If you're looking at central A/C, look for a two-stage or variable-speed system, and for one using R410A refrigerant.

Joe


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## Beno

I think of using an all year around ERV, like Venmar AVS DUO, which performs well enough during heating and cooling season. This may be enough, if not I can add later a split A/C, having 14 SEER or more.

I have an additional question. Do I have to add in the utility room where the Caddy will be located a window? The Caddy will have its own OAK for air intake, and I rather not add a window, unless from your experience is a must (for safety?). Thanks again!


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## BrownianHeatingTech

Beno said:
			
		

> I have an additional question. Do I have to add in the utility room where the Caddy will be located a window? The Caddy will have its own OAK for air intake, and I rather not add a window, unless from your experience is a must (for safety?). Thanks again!



You'd have to check local codes on that.

Joe


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## mtnxtreme

On the oil/wood combo units, can you run the flue  on the interior safely, or should you duct it outside and up an exterior wall.? Also how high, my house will be a 2 story farmhouse, am I limited in chimney height?


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## Gooserider

mtnxtreme said:
			
		

> On the oil/wood combo units, can you run the flue  on the interior safely, or should you duct it outside and up an exterior wall.? Also how high, my house will be a 2 story farmhouse, am I limited in chimney height?



AFAIK, it is the case with ALL chimneys that you are best off going up through the interior as much as possible, so long as you use the proper construction techniques, clearances, materials and all that.  The temperature difference between the flue gasses and the outside is part of what drives a chimney and keeping it inside will make it draw better.  The "outside and up"installs are generally a compromise (usually on a retrofit) when the installer can't figure out a way to route the chimney inside. - exterior chimneys are sometimes known as "evil chimneys" because of their tendency to have draft problems (particularly on startup) and increased creosote buildup.

In terms of height limits, it depends on the unit, the location, etc. but a two story house shouldn't be a problem, as most stoves will give optimal draw around 20-25', and be fine until well over 30'.  Even if you do have an  overdraft issue, there are ways to solve it, such as using a butterfly damper to slow things down a bit.

Gooserider


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## showmemike

i would seriously advise anyone thinking of buying a u s stove product to reconsider. i recently tried to establish my environmental products business as a dealer for their furnaces. they had my money for about a week and did not ship my furnaces. i had to file a complaint with the better business bureau and the tennessee office of consumer affairs before they returned my funds.


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