Infloor radiant wood fired slab?

[Enzocann]

First Off, I am new to this forum having just discovered it. What a wealth of info for the first time yurt erector ! My wife & I are soon to put up our new 30' Pacific yurt on our parcel here in southern Oregon. The driveway has been developed to the homesite and the well is hooked up. My choice of site is based on a need for summer shade balanced with fire safety and being able to work with the grade of the slope. My next task is to-
A) Build a deck platform-Pier blocks,pressure treated lumber, SIP floor & outside TREX decking and heat with interior woodstove(less time,work & $ ?)
OR
B) Pour a reinforced slab with pex for an outside wood fired boiler & hot water radiant floor heat(more time,work & $ ?)
Either option is not cheap- Even if I build the deck with a friend who is a master carpenter( I also know my way around tools and construction)AND has all the tools AND has built 4 different yurt decks, It will be around $6-8000. I already have a stove. My concrete pouring friend says he can make me a 30' reinforced slab with pex for heat and chases for water, sewer, propane & eletricity for probably much less. I would have to sell my stove and get a more expensive boiler. Who does not like the idea of a warm floor in the cold wet Oregon winter, never bringing wood into the house & the interior space freed up by the stove being outside, no smoke or ashes inside ever. BUT- will it keep the space warm enough? Will the cover and walls radiate heat out faster than the slab can warm the interior space when it is 30 or 40 degrees outside for four months straight? I like it warm in my home during the winter months as I work and play outdoors. I love my Vermont Castings Encore stove a lot. Any one have any experience or ideas regarding this scenario? I like to keep things fairly simple and I think that even though the deck option will be more work for me, the woodstove inside is likely to be warmer. The cost of the wood fired exterior boiler will make the slab option more expensive , though I am not against spending the $-If it is a better way to go. Wood is not a problem as I have a sixteen acre woodlot. I bet both options use the same amount of cordwood, so I don't see that as being an issue. Thanks for any insight to my query, Enzo

[Jafo]

Wood boilers use a LOT of wood and you will use much more than you wood in a wood stove.

I like the idea of radiant heat myself because it also saves you space in side.

[Enzocann]

Jafo, I think the size boiler I would need to heat a 700 sq' slab only needs to be stuffed with logs 2-4 times a day, whereas my stove wants logs every couple of hours. I would wager/speculate that it would be about the same rate of consumption. You have to get up & go outside and feed the boiler, but you don't have to bring wood in the house every day. I don't think it is feasible to get the same amount/type of heat from the floor as you would a stove. I guess I am looking for someone to prove/explain to me that I am wrong and that the concrete floor/boiler option is the better one & would be a better use of my resources in the long run. The main issue I am concerned with is the warmth of the yurt. I have lots of wood and the time to process it. As a matter of fact, I have so much wood I am starting a firewood supply business. If I have been out in the cold rainy forest all day cutting wood and come home to my yurt, will the boiler/heated floor have my home toasty when I arrive? I know that even if the yurt is 25 degrees when I get home I can have it up to 80 in about twenty minutes with the Vermont Castings Encore that I have. The place will get cold if no one is home to feed the stove for six or eight hours. The thermal mass of the slab might keep the temperature static, but I don't think the walls and roof will retain enough heat to make it work out right. I think the thermal bleed to the outside will be greater than the gain or the slabs ability to replace it, based on the square footage of the walls/roof versus the floor area alone. The more I write about this, the less sense the slab seems to make to me...

[Bob Rowlands]

There's NO WAY I'd fire a wood boiler to heat a slab, to heat a yurt. I've carpentered on several houses over the decades that have had radiant heat, but the boilers were fired by gas. The owners did nothing but adjust a thermostat. (and pay for the fantastically expensive system of course)

While those radiant heated homes are extremely nice , having to fire a wood boiler to heat the slab, no thanks. Passive or active solar heated slab, yes. I've seen active solar panel heated greenhouse up at 8K feet with incredibly lush vegetables growing inside, so I know solar panels can actually heat a slab. but there's no work involved. Firing a wood stove is enough of a chore. Firing a wood boiler, nah that kinda fun is for the real young imo.

[Jafo]

My neighbor heats his home with a wood boiler. I believe he went through nearly 40 cord of wood last winter. Now that is a large home and he also heats his garage floor with it too, but still. He went through A LOT.

One benefit is though, you can use pretty much any wood you want.

It is a lot of work for him, but if you don't mind that, then it is really up to you.

[ineffableone]

If your interested in wood burning boiler you might want to check out youtuber Engineer 775. He is one of the experts that consults for the show Doomsday Preppers. He is all about wood gasifiers and wood burners and has a bunch of videos explaining these.

[Marshall Eppley]

I like the radiant idea because it is a constant heat as you know heat dissipates in a yurt after the source stops putting out.For this reason i think radiant would be better.but one also needs to know radiant heat takes a while to heat up so to speak because you have to heat everything in the yurt. So what i am saying is when you walk over and change the t-stat you will have to wait for it to get there.But once you figure the system out i think they are great. And alot of your cost you could save by doing it your self. not that hard to install just time consuming. I am a plumber and have done many installations with radiant heat from farm houses to a 200x225 airplane hanger. And ill try an answer your questions if i can.

[Bob Rowlands]

That's what I call the radiant heat 'flywheel effect'.

Consider this though. If you are away from the yurt, and haven't been feeding wood to the boiler, won't that slab get real cold in the dead of winter? I kicked that flywheel concept around and opted to build a wood

yurt platform

, and use a wood stove for heat, when a concrete slab would have been a whole lot cheaper and easier to build. But, I don't live in my yurt.

When I was 10 my parents bought a new rancher was built slab on grade. It had forced air heat. I don't remember there being a problem with

heating

it, but I can remember my Mom complaining about the cold floor. Just saying.

Another point about thermal mass. Log homes are great. I had a buddy whose Mom rented a real log home. The back bedroom where my friend slept was very cold in the winter. The logs just radiated the cold. I'm thinking a real log cabin can take quite a while to heat up if it sits vacant in the winter.

Just some thoughts to consider.

[Marshall Eppley]

Yes bob i agree if you let it get cold it would take a real long time to heat back up for sure. So unless you had some one to feed the fire a wood stove would be more practical.

[Pacific Yurts]

Radiant floor

heating

works well in yurts with radiant barrier

insulation

. Many times people who use a radiant floor heating system in their yurt will have a supplemental heat source powered by electric or gas. When connected to a thermostat this heater will only turn on if the temperature drops below a specified temperature while you are away (to prevent frozen pipes). It can also be used to heat the space quickly while the radiant system is getting up to temperature.

Pacific Yurts

www.yurts.com