Heating with Wood and Propane

[Stabu]

First I have to apologize for not knowing much about boilers. I ended up here after educating myself for roughly 3 weeks on the matter and calling virtually all boiler manufacturers that I could find.

My situation is this: I live in a 1600 sq feet house in New Hampshire that I am going to expand to roughly 2200 sq feet within the next three years or so. I currently have a 300 gallon oil tank that leaks and a Slant/Fin Liberty II oil boiler from 2004 (the house has baseboard heat). Because the house is very poorly insulated, I currently consume roughly 900-1200 gallons of oil per year, even if I keep the heat down at 60 degrees. The boiler itself works fine, but it needs a tune up and I've heard that the boiler isn't of the best possible quality (is this correct?).

I've decided to go with a wood boiler for primary heat with a propane backup. The only two options I've found that can provide this in a single multi-unit are HS Tarm Excel (11-13k) and the Atmos Combined Boiler (4-6k?) (Newmac stopped providing these units even if their website says so and Alternate Heating Systems has so far been unresponsive). Do you guys know of any other manufacturers that have these capabilities?

Another option I recently heard about is to buy a separate wood boiler and gas boiler, and combine them. Apparently it is possible to line these up in a way that would automatically kick on the gas boiler when the temperature of the wood boiler sinks below a certain level - is this correct? In case it is, does anyone know of good and cheap wood boilers and gas boilers (could be of different brands, doesn't matter)?

A third option I'm iffy against would be to by a multi-unit for wood and pellets. So far I know only of two manufacturers that provide this: Atmos and Eko - are there others?

Please be so kind and help me figuring this out...

 

[willworkforwood]

Welcome to the forum - you have come to a good place. 900 gallons oil for 1600 SF (at 60* ) is off the charts. Let me be the first (of many) to suggest that you choose option #4 and put every spare $$ into insulating, weatherstripping, and any other possible energy efficiency improvements to your existing structure. In addition, bring in a qualified HVAC person whom you can trust (ask around), to assess your current oil system. Depending on the cost of a new tank and a tuneup, it may make sense to hold on to what you have now and (maybe) do a fossil boiler upgrade later. If you want information on wood/pellet boilers, you can spend around 6 months reading the archives on this forum. Eventually you can even learn enough to become a tech yourself ;-) But, IMHO, you need to first make a (big?) dent in your current heat loss. If your heat loss/air infiltration issues are complex and difficult; there are some EXPERTS on this forum who can give you top-notch, professional advice on how to fix whatever problems you have. Just describe in detail what your current construction and insulation is, and with some luck one or two of the construction gurus will pick up the thread and give you the answers you need.

 

[Willman]

infiltration and the resultant exfiltration is resposible for roughly 40 ish % of heat loss. It is the easiest (sometimes) way to cut btu use. You would be wise to consider 2 seperate units as a dual fuel has to fall in between of 2 sweet spots.
You should be cutting and splittin your wood for the next year asap as properly seasoned wood works best. 2 year seasoned wood is better as long as it isn't oak.

Will

 

[Frozen Canuck]

As one of the const. folks you have been warned about, I have to agree that your problem likely has little to do with your boiler. I did a fast seat of the pants calc. based on the numbers you provided & the only way I can match it is to leave out the insulation altogether in both the exterior walls & attic space (assuming you have a traditional stick built) home.
It cant hurt to get a service on the boiler from a qualified tech just to be sure, however my guess is that your new summer job (all summer) is going to be opening up the walls & finding out what is really there AFA insulation/vapor barrier/air barrier goes.
Once you have more info you can ask on how to remedy the problem(s), plenty of good folks here willing to help.
Sorry for the bad news but unless the boiler is in the 20% eff. range instead of 80% or above, or that leak you spoke of in the tank is more like a running tap....well I think your problem & therefore the solution to same is elsewhere.
As others have said, provide as much info as possible & folks will chime in to help out.

 

[henfruit]

Hey will, At 2 years old wont oak be ready to burn?

 

[afblue]

Hey will, At 2 years old wont oak be ready to burn?

Oak sometimes takes 3-4 years to dry, it has to do with the grain structure, and is sometimes acidic. Fortunately, my dad's land is Cherry, Maple, and Ash.

 

[Willman]

Oak sometimes takes 3-4 years to dry

+1
Split and stack in wind, single row of splits, properly seasoned it is awesome fuel. A moisture meter is your friend.

Will

 

[Stabu]

Thank you all for responding to my inquiries.
My insulation situation is the following:
Basement (roughly 90-95% underground): The underground part is partially insulated with a quarter inch styrofoam panels. The aboveground part is partially insulated with some poor insulation, partially wide exposed to the cold New England air.
Main floor: I don't know about the insulation at all. I do know that the previous owner redid the siding in 1997 and put tyvec wrap underneath (the house was built in the 60's).
Side attic: R-11 insulation, but it has a couple of loose sections and a piece missing in one corner.
Upper attic: R-9 insulation, with the same problems as noted above.
I'm well aware of this problem and my original plan was to fix the attic and the basement during this summer by putting some R-30 (or more) to properly insulate these parts of the house. Due to your unanimous consent, I'll have a contractor come over to see if we could redo the siding for two walls of the house as well before the winter comes.
The chimney is also a problem, since it lacks a flue and is thus always exposed to open air. My windows are thermopane from 1998, but they were poorly self-installed with gaps between windows and walls.
Overall I believe that these issues are more or less under my control (this is my first winter in this house). My main concern is the leaky oil tank. Right now it leaks a few drops per hour that can be easily caught with two tiny buckets and disposed properly. The problem is that if the leaks get bigger I will have an environmental disaster at hand with EPA after me. Furthermore, I am screwed if this happens in mid winter. The only viable solutions would be to replace the tank, which would cost around $1500 or alternatively get a new boiler system installed. I'm heavily leaning towards the second, because I don't plan on heating with oil much longer anyway since 1) it is smelly, 2) it takes space, 3) and you can't cook with it. What would you guys do in my situation?

 

[willworkforwood]

Well, you're off to a good start by recognizing that the attic is a top priority and have a plan for that. Are your interior walls in good shape? If not, and you have plans to redo them, you will have more options for insulation choices there. If the inside is good, then I believe there are some newer blow-in options that I'm not familiar with (but others on the forum are). Assuming that the windows are at least structurally solid, then you have a relatively simple DYI solution to the infiltration that would probably have a very big payback. Just remove all of the window trim, and use a foam fill to plug all of the gaps (I've had good luck with Great Stuff Window & Door). Tack the trim back in place, and you have nice tight windows. And the bonus for doing all of this stuff is that you would no longer need a 300 gallon tank - another chance to save more $$. But, you said your oil boiler is "smelly". A modern oil burner in good shape shouldn't have an oil smell - it could be a sign of a safety issue. If you're certain the smell is not just being caused by the leak, you should get a tech in ASAP to see what's going on. Personally, I would try to keep the existing system, with an eye on wood as the primary source of heat in the future - that's just me. But you need a pro opinion of the system before you make any decision. Keep going - you're on the right road!

 

[Frozen Canuck]

A few thoughts:
Built in the 60's code was R12 walls & R20 attics. So you will need to upgrade for sure. You mention R9 - R12 in your attics.
That below code install brings into question all your insulation (walls too) as to whether it was done right or even at all. If you can rent an infra red camera, I think you will see a lot of blue/white (cool/cold) areas when viewed from the inside or red/yellow (hot/warm) areas when viewed from the outside. Either of these is evidence of heatloss.
You mentioned replacing the siding, that's when you can add more insulation in the form of high density foam before applying new siding. Aim for R10 min. R20 would be better. You will need to purchase longer fasteners for your siding. Tape all seams in the foam while your at it to reduce air infiltration.
When you get to the attics think R80 min., more if you can of blown in cellulose. You will likely need to install insulation stops as well prior to the blown in as I doubt with an R12 if anyone bothered with installing them.
Get the inspection of the boiler done, as others have said the odor is out of place & may indicate a problem. Don't know what you have for fossil fuel in your area but your choices are in order, 1 nat gas. 2 propane. 3 oil.
In your situation I would insulate as much as possible at every opportunity, make the house as tight as possible (air & vapor barrier), solve the fossil boiler issue(s) either through repair or replacement.
When all of that is done then you can consider a wood boiler if you wish as you will then have a stable heat load.

 

[woodsmaster]

After R - 60 in your attick the payback time greatly increasses. Be sure to seal any open walls to the attick or holes around wires etc. with foam before adding insulation. I would use cellulose rather than fiberglass batts, much easier to install properly with no gaps.

 

[Rory]

Another option I recently heard about is to buy a separate wood boiler and gas boiler, and combine them. Apparently it is possible to line these up in a way that would automatically kick on the gas boiler when the temperature of the wood boiler sinks below a certain level - is this correct?

Yes, my system uses an oil furnace for backup. My wood system employs what is referred to around here as "passive storage". It amounts to a 4x4x8' rubber lined box filled with water that goes nowhere, but absorbs and releases heat as needed. This is accomplished via a heat exchanger made of two 120' copper coils plumbed in parallel to act as one coil - putting heat in when necessary and pulling back out as needed. In addition, I have a 180' copper coil in there that my domestic hot water goes through on its way to the tap, and that's the only thing that heats my DHW. My oil furnace is also plumbed to this system and has a probe that monitors the tank temperature. When it falls below the "setpoint" I set it at, the oil furnace kicks on and heats it up. It works really well, and my wife has never touched the wood furnace. If I'm not around and she uses up the heat from the last wood fire, the oil will simply take over with no intervention.

 

[Willman]

replace the tank, which would cost around $1500

I saw 275 gal. tanks at HD the other day for around $400. Add in the legs and whistle and new filter and possible fill pipe and you should be well under $600 if you DIY. I would have the existing boiler checked out. A few $ spent on it could yield a nice back up to your wood unit without breaking the bank, Put you money in the walls and ceilings for continual payback.


Will

 

[Stabu]

My contractor was over today and found out that the walls have R13 insulation. Is this good enough, or is there a good reason to make it thicker (how thick)? The contractor said that the only way to really increase it, is to redo the sidings - there's no point in redoing the walls from the inside of the house.

 

[Stabu]

I saw 275 gal. tanks at HD the other day for around $400. Add in the legs and whistle and new filter and possible fill pipe and you should be well under $600 if you DIY.

Thanks for the info! I was previously quoted that removing the old tank would be $400, buying a new tank would be $500 and the installation costs would be roughly $600 (hence the roughly $1,500 figure).

 

[woodsmaster]

My contractor was over today and found out that the walls have R13 insulation. Is this good enough, or is there a good reason to make it thicker (how thick)? The contractor said that the only way to really increase it, is to redo the sidings - there's no point in redoing the walls from the inside of the house.

If you need new siding add insulation when you do it, otherwise fix the attick and seal any air leaks.

 

[willworkforwood]

My contractor was over today and found out that the walls have R13 insulation. Is this good enough, or is there a good reason to make it thicker (how thick)? The contractor said that the only way to really increase it, is to redo the sidings - there's no point in redoing the walls from the inside of the house.

If you need new siding add insulation when you do it, otherwise fix the attick and seal any air leaks.

+1
R13 isn’t great by current standards, but it’s also a lot better than having nothing in the walls, assuming fiberglass bats, and not blow-in that has compacted down the walls. Before investing in what would be a fairly expensive contracting job, you should attack the easy, inexpensive things first. There are many ways that air can infiltrate - here are some common ones. Worn door thresholds; worn side/top door weatherstripping; old and cracked window bottom/top seal (usually plastic covered foam); receptacle/switch boxes (not well-surrounded with insulation, and/or missing foam air blocker); gaps behind floor mouldings; loose door knob screws. We already reviewed the known window gap issue, so that one is first on the list. You can probably do a visual on most of these things, but you can also slowly walk the rooms of the house, holding a candle (on a windy day). Some things may show up from that which can’t be easily seen by eye. Your attic is, of course, a huge heat loss factor, but if you have infiltration from a number of these other things, that might be collectively as much, or even more than the attic.