Simple design for in-floor hydronic heat.

[bkvanbek]

I am building a new cabin a center point of the the cabin will be a wood stove capable of hydronic heat. I want a simple one zone design. Where can I learn about how to design one.

ABC Products Concept 2 Hydro Wood Boiler​

 

[GENECOP]

One Zone, 250, 300, ft piping, one circ, therm wire, good to go..mix the water temp down..

Designing a Radiant Floor Heating System (complete guide) | HVAC DIY Tips

Designing a radiant floor heat system can be straightforward or very complicated, depending on many factors. This guide is intended as a basic overview of the radiant design process.

hvachome.net

 

[Rearscreen]

https://www.radiantec.com - they sell DYI kits. Using your wood stove to heat the water might be problematic as water circulates via electricity, should the circulator stop the water around a jacket will overheat - unless it uses a system where a holding tank is a floor above the heat source and depends on hot water rising and cold water dropping creating natural circulation. But, maybe there is a safe system incorporated with a dedicated wood stove that I am unaware of.

 

[DBoon]

I would not use radiantec.com as a resource to design your radiant heating system. Their recommendations are nearly universally laughed at by professional contractors because their design approaches are heavily flawed and the thin plates they sell don't conduct heat very well. I am just a homeowner, not a contractor or radiant heat materials supplier, so I don't have skin in the game in that regard.

I found www.heatinghelp.com a really good resource when I designed and installed my own radiant floor heating system. You will have to invest some time to learn how the systems work. Designing one is not too hard if you are capable at math and can use a spreadsheet. Lots of homeowners who have paid for cheap installations and/or are trying to debug their systems have the following problems (that you should avoid):

1. Using a domestic hot water heater as the heat source (as described by Radiantec)
2. Using thin plates and/or no plates (just tubes) - the thick plates that tubing snaps into are much better (e.g., like these https://www.supplyhouse.com/Uponor-...MI4M_A0cXV7gIV3smUCR1LFgjzEAQYASABEgI3f_D_BwE
3. Not using R-19 insulation under the plates and/or relying on reflective foil insulation
4. Not making sure the house is insulated enough (with low heat loss) to ensure that the low-heat output radiant system will work without the water temperatures needing to be too high (which makes the floors uncomfortable and/or damaged).
5. Having a contractor who has never installed a radiant system before install your system

Good luck. I can tell you that I did research and design my own radiant floor system, got some good targeted advice from people at heatinghelp.com, and my system is working great (at a home renovation I plan to occupy very soon). The heat is very comfortable and worth the work.

 

[Rearscreen]

I would not use radiantec.com as a resource

I actually agree. My mistake for suggesting. Heatinghelp is the source to go to and I personally read "Pumping Away" by Dan Holohan and based on that small book I installed my own boiler and radiant (Onix in the house I live in now). Why I mentioned Radiantec -A week ago a business associate who is about to build an off grid house in NH mentioned Radiantec to me and that's how it stuck in my mind. He sent me a link to Radiantec and a video that shows a domestic hot water heater/radiant floor heater system. When I went to the schematic drawing it was a total head scratcher. It shows, that I would be drinking hot water from my radiant floor system. Huh?
Anyway, I have installed 2 systems myself in my last 2 homes I have lived in. In both cases using the same length loops to keep things simple. House #1 new construction has pex/al/pex in the basement concrete floor and pex between the engineered joists. I did not use heat transfer plates rather, radiant reflective foil stapled to 1/4 inch luan that "dropped" into the lower lip of the I joist which in my case gave about an 8 inch air space. Pex expands and that design eliminated a "tick tick tick" throughout the floor. I have to say, I prefer that design over what I have now. House #2. Needed new boiler and even though it had baseboard, I chose to add a zone of radiant. I also had to use Onix (rubber hose stuff) as it would have been impossible to wrangle pex. I also changed the heating system so it pumps away and has a primary loop to draw from. That all said, in my 2,500 sf Vermont house more than half of which was built in the 1800's, with a Progress and the radiant system, I order 1 tank of oil a year. I can't say enough about Dan Holohans book.

 

[Rearscreen]

Having a contractor who has never installed a radiant system before install your system

Had to laugh at this - I had a friend and went to her house and the heating guy put in radiant (her kitchen actually had a poured concrete floor) and the floor was hot to the touch - I mean hot! I went to the manifold and it was as hot as a baseboard pipe would be! Nice install but the contractor wasn't used to heating with 100 degree water...He came back and fixed it after I explained the situation....

 

[DBoon]

Sorry, Rearscreen, if it seemed as if I was dumping on you about the Radiantec recommendation. Not my intention.

Dan Holohan is well known for steam heat - didn't know he advised on radiant heat as well. John Siegenthaler is another excellent resource - I followed many of his principles in my system design.

No "tic tic tic" in my system, thankfully. I used large holes to get the pex through the joists and I also used those plastic strain relievers in the holes to allow it to move easily as it expands. I think the thicker plates help also in keeping the pex from moving.

This is my post in heatinghelp.com https://forum.heatinghelp.com/discu...me-feedback-on-my-radiant-design-plans#latest

It's a great system, but it is a lot of work to install, so I can definitely understand why not that many people install this type of system.

 

[WiscWoody]

I plan on putting tubes in a pole floor not so much for me since I don’t think I’ll heat the large shed with floors heat but a few have told me it would be good for resale to have them in. I will have to research the project and I was hoping to use two inch Foamular pink insulation board under the cement with a R value of 10 or 11. Any comments? Even if I don't use in-floor radiant heat for the building it will help keep the floor from frost heaving since we have some clay in the soil here and I’d use the insulation with or without the tubes being installed, and]y comments would be greatly appreciated.

Edit, I might built the shed conventionally as a large garage with wall and roof sheathing that I’ll decide when I get close to start building it, so far I waited all summer for the excavator to show up and it never happened even after I called him a few times so I’ll see what happens this summer.

 

[Rearscreen]

John Siegenthaler is another excellent resource

Thanks! I will research him, always good to learn from experts...

 

[SpaceBus]

That cookstove might work to heat the house if you have thermal storage tanks (several hundred gallons of water) and burn it around the clock. The firebox is small and you might get four hours before it needs to be reloaded. Same story if you are using it to heat the house without the water jacket, but having the water jacket installed allows you to heat a room that might be closed off from the room with the stove. Perhaps a situation where a small house has an upstairs that doesn't get heat from the first floor very easily or if the cookstove is in a basement.
If I had my laptop I could write a more coherent and in depth response.

A more realistic solution is to have two stoves, but you will have a lot of money invested either way. We have a small freestanding cast iron stove that is the primary heat source, but I also cook frequently on our wood cookstove that has a water coil for heating our domestic hot water.