Massive uninsulated old house in need of heating system

[brenndatomu]

In that case why would you recommend an indoor furnace apart from not having to go outside once a day?

The radiant heat of the furnace is "wasted" to the house, not outdoors...keeps the basement fairly warm without even "actively" heating it.

 

[maple1]

Question though: it seems like there are EPA outdoor boilers that are 90% efficient, meaning they would burn the wood gas just like the indoor ones. In that case why would you recommend an indoor furnace apart from not having to go outside once a day?

There is no way an OWB is 90% efficient. The best indoor gasifiers with storage aren't (quite) that efficient. Having said that, the right one may be a reasonable solution for your situation.

 

[brenndatomu]

There is no way an OWB is 90% efficient.

Exactly

 

[Highbeam]

You can always build a small detached shed for an indoor boiler. Folks have done that. After all, what is the difference between an indoor boiler and an outside boiler?

 

[E Yoder]

I think the differences between the indoor and outdoor boilers are being increasingly blurred. If a boiler has passed the EPA 2020 standard and has efficiency testing done by a real independent lab the actual lab numbers are pretty accurate. The test method required by the EPA is very precise and requires burning at various burn rates on the non-storage boilers.
Some of the "outdoor boilers" are indoor rated also, so again, the terms are confusing.
A look at the EPA's list of 2020 compliant models (Google it) is a good place to start. You won't find any of the old style smoke dragone on there. Keep in mind the list is about 4-6 months behind so some models aren't on there that got tested this winter/spring.

 

[maple1]

You can always build a small detached shed for an indoor boiler. Folks have done that. After all, what is the difference between an indoor boiler and an outside boiler?

That's also an option. Actually, if I wanted a boiler but didn't want it in or couldn't put it in my house, I would put it in an outbuilding big enough for it, storage, the whole winters wood, and some extra (heated in the winter) shop space. That makes heating with no power a lot more challenging, but there are ways around it. Likely involving a UPS/generator setup. Or just a stove in the house to get by until it comes back on.

All kinds of variables & possibilities here - not an easy decision with the $$ involved.

 

[Bad LP]

You could not pay me to run any outdoor wood boiler. No way.
I'm no more afraid of my boiler in the basement than I am of my wood stove in the LR. Both are well maintained and I burn nothing but dry wood in them. I'm well aware that if the house catches fire for any reason it will not be saved by the FD due to my location so I don't skimp on my homeowners policy.
Now as far as the costs for equipment and install it ain't cheap nor is the equipment to harvest the wood. To date I've bought my wood cut not split from my local guy because I don't have the free time. That will change when I live there full time. God knows I could use the work out.
As for putting it into an out building that's an option however that also comes with a price tag. All the stuff I've bought and most of it used in very good condition could have bought one hellofa lot of propane.

 

[brenndatomu]

All the stuff I've bought and most of it used in very good condition could have bought one hellofa lot of propane.

All that stuff is still worth something...but used propane is worth even less than used oats...

 

[salecker]

The highest rated EPA cordwood boiler is a central boiler model at 84%. I would expect that this level of efficiency is conditional, like it only gets that when running flat out with no idle.

That's okay though because wood btus are cheap. Electric baseboard heaters are 100% efficient but those electric btus cost a lot.

There are the Econoburn outside boilers.I have one and would be willing to bet that it is more efficient then the C.B. lineup
I have mine in a building with storage.The outdoor Econoburns are the same unit as the indoor ones.There is a bigger shell around them and sprayfoam insulation as apposed to bat insulation.
I have to reload it every 3 hours depending on the amount of time i have to burn to max out my storage.
Going on 10 years of burning in a different building and a 125ft walk each way.
I would not change a thing.I have a warm workshop 24/7 that i can go escape into and enjoy my favorite legal relaxant.Then i can work on any dirty stinky project i want.
Zero dirt,bugs,smoke,ash,or smells to worry about.
Plus the biggest bonus here is the threat of my home burning down is drastically reduced,and zero chance of carbon monoxide poisoning.
I look forward to the walk even when it's -40,it gets me out of the house and a good chance that i will work on one of my projects while i am there.

 

[Highbeam]

There are the Econoburn outside boilers.I have one and would be willing to bet that it is more efficient then the C.B. lineup
I have mine in a building with storage.The outdoor Econoburns are the same unit as the indoor ones.There is a bigger shell around them and sprayfoam insulation as apposed to bat insulation.
I have to reload it every 3 hours depending on the amount of time i have to burn to max out my storage.
Going on 10 years of burning in a different building and a 125ft walk each way.
I would not change a thing.I have a warm workshop 24/7 that i can go escape into and enjoy my favorite legal relaxant.Then i can work on any dirty stinky project i want.
Zero dirt,bugs,smoke,ash,or smells to worry about.
Plus the biggest bonus here is the threat of my home burning down is drastically reduced,and zero chance of carbon monoxide poisoning.
I look forward to the walk even when it's -40,it gets me out of the house and a good chance that i will work on one of my projects while i am there.

Fortunately we don't have to guess anymore or be tricked by misleading marketing. The EPA now publishes the list with efficiencies. The kuma furnace for example, makes a respectable 79% heating air. Only a few % below a good cat stove!

I really envy your workshop boiler. Glad it's working for you. The only EPA listed econoburn model is the EBW 200-170 which was not clean enough to be 2020 compliant and only makes 60% efficiency. That central boiler is much more efficient but maybe lacks something else?

 

[woodey]

The kuma furnace for example, makes a respectable 79% heating air. Only a few % below a good cat stove!

And I like that the Kuuma furnace is cat free.

 

[brenndatomu]

And I like that the Kuuma furnace is cat free.

More of a dog guy huh?

 

[salecker]

Fortunately we don't have to guess anymore or be tricked by misleading marketing. The EPA now publishes the list with efficiencies. The kuma furnace for example, makes a respectable 79% heating air. Only a few % below a good cat stove!

I really envy your workshop boiler. Glad it's working for you. The only EPA listed econoburn model is the EBW 200-170 which was not clean enough to be 2020 compliant and only makes 60% efficiency. That central boiler is much more efficient but maybe lacks something else?

Too bad there isn't a test that is actually the same for each boiler...
i have read on Hearth that the testing is done in house instead of an independent tester.
If that is actually the case then i see why you can't rely on the EPA numbers or list
kinda like comparing apples and cars

 

[maple1]

Then you have combustion vs. delivered.

I would be very interested to see accurately measured numbers, on the same 'EPA' (gasifying) boiler (capable of either indoor or outdoor use), installed & operated each way, showing % of BTU potential that actually makes it into the living space in either situation.

Don't think I've seen numbers on that aspect anywhere.

 

[brenndatomu]

i have read on Hearth that the testing is done in house instead of an independent tester.

Not anymore...for EPA 2020 certified stuff, the numbers come from certain approved independant labs now...not to say that most didn't do their own in house testing before going for the EPA cert. test...that would only make sense. And those very likely were the numbers that were posted prior to 2020.
From what I have read of what some manufacturers have posted about the testing process, even though the current emission limited require a well designed burner to pass, the test still can be skewed a bit by the operators skill, and some luck, or lack of skill, and bad luck.
And it is cordwood after all, so...

 

[Highbeam]

Too bad there isn't a test that is actually the same for each boiler...
i have read on Hearth that the testing is done in house instead of an independent tester.
If that is actually the case then i see why you can't rely on the EPA numbers or list
kinda like comparing apples and cars

I believe you read wrong. The epa listed efficiency for 2020 compliant models comes from independent laboratory testing. The whole purpose is to be able to compare apples to apples. It’s an expensive test and I’m sure there’s a backlog so any manufacturer would be smart to pretest but those pretest numbers don’t make it to the epa list.

It’s not combustion efficiency only. It’s the efficiency of the whole appliance at converting fuel to hot water. What you do with that hot water is your problem and I bet a lot more of that heat is lost to the atmosphere when the boiler is outside.

 

[Seasoned Oak]

I heat a lot of old uninsulated homes while under construction with a good old hot air indoor wood stove ,but you need a big one, 3 Cu ft at least.

 

[Polomago]

Yes running flat out the boiler may be that efficient so if you size the OWB for the coldest day of the year you may hit that level but any other time you dont need the heat, the boiler is going to idle at a far lower efficiency. You could install storage on an OWB but there is lot of mass in the system to heat up and cool down. Of course you could go with Garn but I think you are too small of a load. An indoor wood boiler is relatively small so it runs full out to heat u the storage and then cools down with far less mass.

The US states didnt ban OWBs for the heck of it, they were a long running problem designed as a loophole. There were plenty of lawsuits and studies. In most states. they finally put an outright ban or severe limits on them. States that offer incentives for energy efficiency do not pay them on OWBs. Feel free to go cheap but you are just going to learn it the hard way.

So here is update: i just got the inspection done. The house has some kind of modern/recent insulation to it in the walls and in the attic floor. So i m going to leave it as is in terms of insulation. I have to put in some money on redoing the roof and the rest of my renovation money will go into a better heating system the the existing electric baseboards. I was talking to the inspector about doing hot water radiators, with a hot water tank heated by a wool boiler. But there is no existing piping in the house, and he says the piping cannot be pex, it has to be steel piping which is crazy expensive. So as we were discussing how to heat the house, it sounded like the best option would be a wood furnace for the bottom floor. With ducts system in the crawl space were the furnace would be installed (6 to 7 feet clearance). And a thermo pomp for the top floor with ducts going from the attic, blowing hot air from the ceiling of the rooms. Blower would be in the attic.
Does anyone have thoughts about this?
And what about not being to use pex for radiators and a wood boiler?
Thanks to everyone for your input!

 

[andym]

So here is update: i just got the inspection done. The house has some kind of modern/recent insulation to it in the walls and in the attic floor. So i m going to leave it as is in terms of insulation. I have to put in some money on redoing the roof and the rest of my renovation money will go into a better heating system the the existing electric baseboards. I was talking to the inspector about doing hot water radiators, with a hot water tank heated by a wool boiler. But there is no existing piping in the house, and he says the piping cannot be pex, it has to be steel piping which is crazy expensive. So as we were discussing how to heat the house, it sounded like the best option would be a wood furnace for the bottom floor. With ducts system in the crawl space were the furnace would be installed (6 to 7 feet clearance). And a thermo pomp for the top floor with ducts going from the attic, blowing hot air from the ceiling of the rooms. Blower would be in the attic.
Does anyone have thoughts about this?
And what about not being to use pex for radiators and a wood boiler?
Thanks to everyone for your input!

The boiler guys will chime in, but you can indeed use pex lines on the distribution side. Where you need steel or copper is between the boiler and storage tank. An ideal setup would be to install radiant floor heat on the main level and a couple panel rads on the second.

7 feet is bare minimum for installing a wood furnace in my book. Don't underestimate the cost of installing metal ductwork either. It's not cheap. A stand alone wood furnace can be very simple to install tho.

Im not a big fan of ductwork in the attic. If you can get a heat pump that does not require ductwork above the ceiling, you'll save some efficiency for sure.

 

[brenndatomu]

But there is no existing piping in the house, and he says the piping cannot be pex, it has to be steel piping which is crazy expensive.

Is that a Canadian rule?
I wonder if the term "boiler" threw him off...he was thinking steam? Technically it would be a wood fired hydronic heater. (wood fired water heater)

So as we were discussing how to heat the house, it sounded like the best option would be a wood furnace for the bottom floor. With ducts system in the crawl space were the furnace would be installed (6 to 7 feet clearance). And a thermo pomp for the top floor with ducts going from the attic, blowing hot air from the ceiling of the rooms. Blower would be in the attic.
Does anyone have thoughts about this?

No ducts in the attic...that just doesn't work well with a modern forced air wood furnace...not the best plan with any furnace really.
I don't think 6' would be enough headroom to pull off a wood furnace...my basement is 6' 10"-ish and that was plenty tight enough to pull off! Guess it somewhat depends on how much headroom you want/need though too...

 

[E Yoder]

I don't get the "no pex" idea, it's been done many thousands of times and works great using a wood boiler, propane, etc. It's just a hot water heating system, I ran a bunch of pex yesterday in a house, lol.
On the whole efficiency discussion, manufacturers are required to provide the EPA qualifying test info to anyone that wants it. It has dates, location, pictures, burn rates, and numbers on every test run. Independent lab testing is a requirement using a specific test method, so it's a pretty level playing field.
That said, there's nothing stopping a manufacturer from posting "combustion efficiency" etc. So I'd go by the EPA database.

 

[peakbagger]

Someone familiar with Quebec codes will need to chime in.I seriously doubt Quebec would ban PEX.

 

[maple1]

First I have heard of 'no pex'. It is universally used. He must have been thinking steam? Maybe the word 'boiler' did throw him off, but hydronic heaters are commonly called boilers so not sure what's going on there. But PQ is like another country all together sometimes, so ?.

There is no way I would put any part of any heating system in an unheated space. Especially an attic. Especially in cold Quebec. I know some do it (likely in warmer climates), but no thanks here.

Also, anything burning wood inside will need a good chimney. Don't think we've heard about that situation yet? I would only do an insulated stainless one.

In a situation like this, some of the deciding factors come down to personal preference also. Which we can't likely help with. But I am kind of thinking right now that an OWB (Heatmaster G series?) together with an electric boiler inside for backup (for when you will be away, and assuming cheap Quebec hydro rates) might be your way to go. (Maybe add a wood stove inside somewhere for power outage backup?). I think I would approach it from the distribution side first. And go hot water, zoned, and plumbed to a rad in each room (with pex). That will give the most & best overall heating comfort. Which should be the main factor thinking long term, and add value to the house. Then you can heat the water different ways. Wood (outside?), electric boiler, even an oil boiler or natural gas if available. Or maybe even an Air-Water heat pump in the future, if that tech keeps progressing. The heating part can be changed over time if a need to do that arises. The distribution part, that's long term & should be gotten right the first time & do the life of the house. But short term vs. long term, and etc.? That gets you into those personal decision factors stuff.

 

[Bad LP]

No PEX allowed doesn't sound right.

 

[salecker]

I have pex in my system.
The underground is pex and all the runs in the house to recycled CI rads are pex.
Everything in my boiler building is copper,recycled.