New Log Home build, Need design help

NateF350

Hi guys my names Nathan, found this site while researching heating options . I'm getting ready to build my house this spring and I want to go Radiant in floor heating. I'm looking for someone to help me design the proper system for the house. I'm building in western pa is there anyone you guys would suggest? Right now I'm looking into underfloor system using the Thermofin C plates or Warmboard. I've already been in contact with warm board. All Advice is welcome! Thanks!

Gordy

Will,this be a full log home?

Gordy

Warmboard is an excellent product. Look into sun board also. I would avoid under floor system. As if this is going to be a full log build the infiltration factor is forever changing over the life of the home. Especially if chinking is allowed to go unmaintained.

NateF350

Yes it will be a full log home, using hand peeled Red pine 12" on the big end 7-8" thick on the small end. 20ft ceiling catherdral ceiling in the great room and 25ft in the kitchen/dining room. I looked at sunboard but haven't contacted them yet. I was a little thrown off by there alum. thickness stated online. One place it listed .10 and then in the brochure it list .007. Is the graphite option something worth looking into in your opinion?

Harvey Ramer

Many times a full log home cannot be heated solely with radiant floor. That's not a big deal though. All you need to do is add supplemental heat to what ever rooms need it. I like to supplement with flat panel rads, they look gorgeous on log walls.

I find that a supplemental rad can be piped in parallel with the radiant floor (controlled by the same thermostat ) as long as you are running an ODR curve. The panel rad has a nonlinear btu output proportional to water temp, where a radiant floor has a linear output proportional to water temp. This phenomenon allows for warmer floors during shoulder seasons, which is nice.

Be very careful and conservative with your design. I would allow a generous fudge factor in your emitter sizing.

Gordy

I agree with Harvey, and will keep my opinion of full log design to myself.

Rich_49

Log home in Western Pa ? If Harvey is not interested in assisting and / or designing , call me . We regularly do remote work and provide support .

Really need more details about how this is to be constructed .

Paul Pollets

I've done radiant in log homes and as Harvey said, they often require supplemental heating. The project should be put through a radiant program ( Uponor ADS or Viega) to determine the water temps required. Then you'll know for sure if the house and selected application can keep up with design temps.

Ironman

Rich said:

Log home in Western Pa ? If Harvey is not interested in assisting and / or designing , call me . We regularly do remote work and provide support .

Really need more details about how this is to be constructed .

Where in western PA?

I'm in VA, but will go that far if you don't hook up with Harvey or Rich.

NateF350

Thank you for all the responses, what you've mentioned has been a big concern to me about using radiant heat and why I was looking into warm board. I attached a picture of my layout and will give you guys the run down on construction. The main part is 36'x36' with a 20'x24' wing. Full basement with 5' slab and radiant heat in it. I'll be using open joist on the first floor and ether 3/4" ply or warmboard. Kitchen and mudroom will be tile/stone the rest of the house 3/4" hardwood. The dining room area is 16'x16' and has a 25' cathedral ceiling, the great room is 20'x24' and has a 19' ceiling. There are 2 -6'x3' facing south and 2- 2'x3' Windows in it. There a loft above the rest of the house and kitchen which is 16'x8'. The loft is 20'x14' with two bedrooms. Logs are red pine with an average R valve of 8 (at least that's what I was told). I'll be using Sashco chinking inside and out with foam backer. The roof is 2x12's rafters, reflective foil insulation with 5/8" T&G over it on the inside, R38 blown in insulation, 5/8" osb and vapor barrier on top. I'm going metal roof so in between the nailers I'll put 1 1/2" blue board down. Beside the great room there's no real big windows anywhere just what I need to meet code.

I plan on using warmboard or sun board upstairs in the loft bedrooms which I don't think I'll have much problem heating as all the walls will be studded and insulated. I know the open to aboves are going to be my problem areas. What I though about doing is going with warmboard or sun board and seeing how well it heats the house. If I needed more heat I was just going to add baseboard where I needed as I could put it in later paint it to be close to the color of the logs. I have a decent sized fireplace in the great room. From the picture you can see when I do my fireplace I do a full brick fireplace to surround the flue liners then I'm going to do my 5" real stone on the outside of that.(blue is stone, red brick, brown flue liners) There's a ton of mass there, what I though about doing was running 1/2" pex between the brick and stone for additional heating capacity. Anyone ever done it? Thoughts? We have a fireplace at our camp just like this and even with a fire going the stone never gets hot to touch, it'll get warm for a couple feet around the opening but the rest of it stays cool.

Gordy

What makes it tough is r values with logs are not consistant along with infiltration over the life of the log home. Have you considered half log. I know several people that have full log, and have issues with water seepage, infiltration, settling etc.

Another thing is wood floors will limit water temps a little.

NateF350

I'm about 1 1/2 north of Pittsburgh. Haha No won't even consider half logging it, I have a hard time calling these milled log homes they do these days log homes. That's why we cut and peeled all the logs. I know I'm limiting myself with the 3/4" wood floors but it's what I like and that's what's going in, I'll work the heating system around it. While I agree there are those problems with logs homes I think it comes more from the quality of the builder and construction process then anything. My grandfather and dad have built 4 log homes now plus we built our log cabin camp almost 15 years ago and we've had very few issues other then routine matnience needing done.

Ironman

The attached shows the btu output of several different radiant floor systems. It was done by the engineering department at VA Tech. The results are with 110* SWT. Higher water temps can be used to increase the output, but good radiant design usually shoots for 120* or less.