So I am going to be moving into a 90 year farm house that is moderately insulated here and there. It is currently being heated by an extremely inefficient owb. Current wood consumption is roughly a pickup truck load per week in winter. My questions revolve around finding the correct boiler, and whether I should heat with the current forced air setup or take the dive and attempt to install radiant heat in the floors(two story house). My initial choice was the garn junior but after reading multiple threads on it I don't believe it would work very well with forced air as that requires a higher water temp to adequately heat a home when compared to radiant. Lots more questions but I'm trying to keep my head from spinning any more than it already is. Thanks in advance.
greenhorn with too many questions about wood boilers
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cityboy172
Feeling the Heat
The garn can do it, the coil in the furnace just needs to be sized for your btus at the lower temp, not the higher temp.
Coal Reaper
Minister of Fire
The garn seems to be a much simpler, more robust design than most other boilers. I've read quite a few reviews about having to replace or repair the refractory cement in the second burn chamber on most upside down boilers. On top of that having to split wood down to the size of a playing card does not sound appealing. But I could be wrong, if so please enlighten me!
A good first step would be to try and get at least a rough estimate of heat load. Was this house heated with oil, gas, or propane at any point in the past? Records of fuel consumption can be used to get a reasonable estimate, which is important in helping to decide how big a boiler you need and how much wood you can expect to burn.
Unfortunately, the delivered BTU output per cord of wood in an OWB varies widely depending on wood type and condition, burn patterns, heat loss to underground lines, OWB model, and many other variables. It's difficult to get a good estimate of heat load from OWB wood consumption, even if you were able to measure the wood consumption accurately.
Unfortunately, the delivered BTU output per cord of wood in an OWB varies widely depending on wood type and condition, burn patterns, heat loss to underground lines, OWB model, and many other variables. It's difficult to get a good estimate of heat load from OWB wood consumption, even if you were able to measure the wood consumption accurately.
I second the idea above about a good coil enabling units such as the Garn Jr to operate more effectively at lower temps. That being said, depending on how you use the Garn and what your actual load is you may not need to worry about the coil as much.
I wouldn't give up on the Garn based on the perception of higher output requirements in forced air setups. Like Nofossil said, try to get an idea of current load. This is step 1.
I wouldn't give up on the Garn based on the perception of higher output requirements in forced air setups. Like Nofossil said, try to get an idea of current load. This is step 1.
Our old house grew as the family and income grew without ever imagining electricity, plumbing or central heat. Consequently the root cellar where the furnace/blower lives is a long way from the sun room and kitchen where we spend most of our time. In our case that puts the farthest vent (kitchen) roughly 60-70' from the HX of our forced air system. Because of the long duct runs once the water temp going into the HX gets much below ~mid-140's F the temps in the house vary significantly as you move closer to or away from the root cellar. I would love to have radiant but it would be a massive job and we need the ductwork for AC anyway. Which means for us to keep the first floor a reasonable uniform temp with forced air, we choke the vents near the HX and keep the water temp high enough to provide acceptable temps in the far rooms, which is ~70F near the HX and ~64-66F (or lower on very cold days) in the far rooms. We don't have a long heating season and it's part of the "charm" of living in a house like this. So obviously if your HX/blower is more central you'll be way better off with forced air than we are. If our heating season was longer and colder like Michigan I'd probably bite the bullet and do radiant if it was possible in our home. Garn has one of the highest customer satisfaction rating here and really isn't way more expensive than what we've done with separate boiler, underground, and storage systems. There's been several good threads where Heaterman (a Garn installer) chimed in providing good insight on using the Garn in forced air applications. The best post I recall discussing this was about 2 years ago, but it's out there.
Thanks for the responses, there's a real wealth of knowledge here.
No, the home has never had any gas/oil heat at all. Always been a wood stove in the basement. That is part of my confusion. I understand that you can pay to get a btu assessment done but how would that possibly work with the unknown variables involved with an old second hand owb as stated above?
I also have not ruled out any boiler other than a garn so if anyone has a boiler that they feel could work better in my situation then by all means, fire away! I plan on installing the boiler in an outbuildings roughly 100 feet from the home and have plans on eventually heating a 24by 32 garage.
No, the home has never had any gas/oil heat at all. Always been a wood stove in the basement. That is part of my confusion. I understand that you can pay to get a btu assessment done but how would that possibly work with the unknown variables involved with an old second hand owb as stated above?
I also have not ruled out any boiler other than a garn so if anyone has a boiler that they feel could work better in my situation then by all means, fire away! I plan on installing the boiler in an outbuildings roughly 100 feet from the home and have plans on eventually heating a 24by 32 garage.
If you have a full basement then you're way ahead of my situation. There are ways and programs the guys here mention that can provide estimates for the heat load of your home given a bunch of assumptions. Other's more experienced than me will hopefully chime in and point in a direction, website, or professional to help you. Sizing the boiler for these systems is a big deal, especially if you really don' t have a working system as a starting point. Our boiler barn is somewhat farther away than you're planning but plenty of us here have working systems like you're planning. Including a bunch of Garn owners.
BTW, a crude but pretty reliable indicator of the better boilers can be identified by the number of messages in a poster's personal data. Two very experienced guys are above with thousands of posts and happy EKO users. Guys who aren't pleased with their systems disappear or swap their boilers (several of those here). Not a perfect indicator, but it's a useful trend for the quality systems. Pick any post, look for the guys with big message numbers then look which boiler they own. With better than 90% probability it'll point you to happy operators and good systems.
Best wishes.
BTW, a crude but pretty reliable indicator of the better boilers can be identified by the number of messages in a poster's personal data. Two very experienced guys are above with thousands of posts and happy EKO users. Guys who aren't pleased with their systems disappear or swap their boilers (several of those here). Not a perfect indicator, but it's a useful trend for the quality systems. Pick any post, look for the guys with big message numbers then look which boiler they own. With better than 90% probability it'll point you to happy operators and good systems.
Best wishes.
Just checked out the price on the eko line of boilers. Very attractive price I gotta tell you but what does storage cost and is that unit designed to run a pressurized system which, I understand, is more efficient and less of a maintenance issue with water testing.
alaskawild
New Member
I agree with Nofossil. You really do need to know what your heat load is. I am a hydronics fan. If you can access the bottom of your floors staple up radiant works very well. Of course there are some caveats to that statement. It can only perform so well if it is put in a barn! With adequate insulation, staple up works great and IMO you do not need all of these reflectors being sold by various manufacturers. Another route that I've used in the past involves using Euro style wall panel radiators. Biasi and Pensotti make excellent units. I've used these in the past with water temps of 140 degrees and they perform very well. You can use their water temp correction tables to appropriately size the radiators at reduced water temps for your btu requirements. They work great for retro work! IMO a lot can be said for not having an air handler.
That was actually what I was going to do in the basement. Figured a pex run every 8 inches and then foil covered foamboard underneath that to push the heat up. The only problem would be heating the second floor. I don't really want to rely on gravity to heat the bedrooms. Maybe run a water line up through the wall to each room and install a radiator of sorts? Questions, questions.
Coal Reaper
Minister of Fire
Radiant is the best delivery for use with a garn IMO. There are low temp emitters similar to baseboard.
Eko is typically pressurized. Used propane tanks run $1/gal. Then insulate. Need a way to know what storage temps are (x-300!) $500 on expansion tank for every 500 gallons of storage. Plumbing and fittings. Double the cost of whatever you think your fitting estimate should be. $80-200 on circulator. Dont forget the $600 loading unit! These are all ballpark.
Consider how easy/difficult different units are to clean.
Eko is typically pressurized. Used propane tanks run $1/gal. Then insulate. Need a way to know what storage temps are (x-300!) $500 on expansion tank for every 500 gallons of storage. Plumbing and fittings. Double the cost of whatever you think your fitting estimate should be. $80-200 on circulator. Dont forget the $600 loading unit! These are all ballpark.
Consider how easy/difficult different units are to clean.
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Google "heat loss calculator" and you will find some good tools. SlantFin used to provide one of the more popular tools but I'm not sure they still do outside of a iPhone app.
These calculators will let you input data about each of your rooms, number of windows, doors,etc and it will give a pretty good estimate of your design load. It will not be perfect but should be higher than actual if anything. This would be a great place to start.
And last, if you don't go with storage right off the bat don't worry too much. Plenty of folks run these boilers without storage and are quite happy.
These calculators will let you input data about each of your rooms, number of windows, doors,etc and it will give a pretty good estimate of your design load. It will not be perfect but should be higher than actual if anything. This would be a great place to start.
And last, if you don't go with storage right off the bat don't worry too much. Plenty of folks run these boilers without storage and are quite happy.
I have a two story house also here in MI that was all electric baseboard heat. I figured I was looking at $600 per month in January for heat alone. I was replacing the carpet in the second story, so I also cut access holes in the drywall in the first floor, cut holes in the subfloor in the second floor, and ran half inch pex to Buderus panel radiators, one in each room in the second floor. I put in Thermofin panels with pex in the joists under the first floor. Design temperature is a -20F day, and heating load can be met with 145 degree water.
Components were much more expensive than installing ductwork and a furnace, but we don't need AC in the UP, I don't like hearing a furnace run, and I didn't want to hack the walls up even further or install odd looking chases to get the ductwork to the second story. Having floors that aren't cold in January is a tremendous bonus.
Ran last year on an LP boiler, hooking up the wood boiler now.
All that said, If I had functional forced air heat I would have installed a wood stove in the living room and been over in a different part of the site.
The builditsolar website had a ballpark heat loss estimator. If you are willing to put your pencil to paper and get a better estimate (a necessity if you are going to drop the coin on radiators and under floor heat and expect it to work) download the Uponor Complete Design Assistance Manual, and the Zurn Radiant Design Manual, both free PDFs available from each company. They both walk you through simple examples which you can use to determine exactly what you need.
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alaskawild
New Member
Checkout these 3 pages concerning emission plates. I agree 100%. My experience has shown this info to be true.
http://www.radiantdesigninstitute.com/page11.html
http://www.radiantdesigninstitute.com/page12.html
http://www.radiantdesigninstitute.com/page13.html
http://www.radiantdesigninstitute.com/page11.html
http://www.radiantdesigninstitute.com/page12.html
http://www.radiantdesigninstitute.com/page13.html
Thank you for that information. It was just what I was looking for as well as the answer I was hoping for! Those aluminum transfer plates are expensive!
alaskawild
New Member
One last thing about staple up. You can use something like the Peter Magone nail clips or talons to attach your tubing to the underside of your floor but it will be noisy with the tubing's expansion and contraction. If you want a completely silent floor use these pex clips http://www.supplyhouse.com/Wirsbo-Uponor-F7051258-1-2-PEX-Clip-100-box-2208000-p . You will not be disappointed! Also just a FYI, the Rifeng grade B PEX with ox barrier from Supply House is GREAT tubing and you will not beat their price. I use it all the time. Great quality product! Good luck!
http://www.aluminum-solar-absorbers.com/
If you need absorber plates, check out this site. Tom Sullivan rolls out absorber plates with really good fit and they are priced right. Thicker material than most I think. If you are in UP -he is in your part of the woods. I used these for wall radiant and homemade solar collector. They are better than others I have seen that are not extruded alum.
If you need absorber plates, check out this site. Tom Sullivan rolls out absorber plates with really good fit and they are priced right. Thicker material than most I think. If you are in UP -he is in your part of the woods. I used these for wall radiant and homemade solar collector. They are better than others I have seen that are not extruded alum.
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