Radiant Hydronic floor heating

[Mark Circo]

Hello

 

Has anyone built Hydronic floor heating into thier Log home. I am considering Warmboard as the subfloor. I would appreciate hearing the pros and cons of one product over the other.

 

 

Regards

 

MARK

[Norb]

Mark,
I am in the process of building a log home with geothermal radiant heating using Warmboard. Warmboard was recommended by the geo contractor who has 30 years of experience with radiant. It is compatible with hardwood flooring. It is very easy to zone for different heating requirements (warmer bathrooms, cooler bedrooms). The builder thought it made a very durable subfloor (1.125 inches thick) and was very easy to install. The Warmboard folks were easy to work with, prompt, and very thorough. The product isn't cheap, but it does offset buying subflooring, it is more heat efficient, heats up quicker, and has better heat uniformity. They will send you a sample of it to learn from. The home is still under construction so I can't tell you how well the radiant system is working yet. Good luck with your project.
Regards, Norb

[john zinckgraf]

Norb, approx how much/linear ft does the warmboard cost? We want to build a loghome and would ideally like to go radiant, at least on main floor. But, I'd like to know how much more than say baseboard hot water are we talking. 2X, 3X, 4X more??? Also, doesn't the warmboard act as the finish flooring as well?

[Norb]

John,
You would be better asking Warmboard for cost because it depends on your design: how many sq. ft., how many zones, how many floors, where obstructions are....etc. ,and on how far they have to ship it to you. To give you a ball park, I'd say 7.50 or $8.00 per sq. ft. I can't give you an estimated difference for a baseboard system because that wasn't the direction I wanted to go. A geothermal system gives you a 30% tax credit now. Warmboard is only a subfloor; it has the structural plywood faced with an aluminum plate and channels are precut into the panels which will contain your radiant tubing (purchased separately). You have to cover the tubing and aluminum plate with your finished floor (ie. hardwood, laminate, ceramic tile, or other). www.warmboard.com can give you more information.
Regards, Norb

[Dennis Cruse]

I would be very interested in hearing more, also. I have been looking at geothermal hydronic radiant floor heat, also. This product sounds great, but expensive too. Would a home need a forced air system for cooling as some other systems do? Is there a PSI or PSF limit on the warmboard? I didn't find these answers on the websites I went to. Do you have any pics? What company did you purchase through? Keep us posted! Good luck!

Thanks,
Dennis

[Norb]

Dennis,
Specs and Q&A on Warmboard can be obtained from Heidi Johnston (1-877-338-5493) at Warmboard. You can even download the installation manual and see pics at their website. I purchased the Warmboard directly from them. I used a local geothermal contractor to do the heat pump, geo trenching, HVAC runs, and tubing install. You are correct. A radiant heating system won't give you cooling in the summer. I am using a geothermal heat pump which does radiant heat in the summer and geothermal-sourced forced-air cooling in the summer. The system isn't cheap but the ground is a great energy source and the tax credit put the system in reach if it is important to you. Good luck on your project, too.
The theme on the loghome site, is that the journey to achieve your dream is a long, complicated road, but the journey is worth the price of admission. You will need to learn a lot about many different topics. The voice of experience from those who have faced similar questions or problems is a great resource. I learned much from those who have gone ahead of me on this journey. I'm no expert, but I've had to learn what is quality and what is junk in order to protect my project. Work with people (contractors, builders, log home companies) you can trust; you can feel it in your gut. Go to the experts, ask lots of questions, and watch out for people that only have "opinions." Opinions can be formed from incomplete, or inaccurate, information, and perceptions.
Regards, Norb

[Mark Circo]

Hello Dennis
I went with the Warmboard for my sub-floor on the 1st floor only. It is pricey but there is a additional value that goes along with the price tag. I talked to contractors who used in their own homes and said it is worth it when your are standing (in your bare feet) of your home on a cold winters day without a cold spot in the room. Cost was $6.29 sq/ft. but for that price they also design the loops and manifold locations. Give them a call they are nice people to work with. If it is used as part of a Geothermal system I think you get the tax credit, not sure.
My dilemma now is which heat pump to go with. I am leaning towards Waterfurnace. If anyone has been down this road, please share your thoughts.

[Norb]

Mark,
I went with a Waterfurnace Synergy 3D. Whatever unit you go with, make sure it is EnergyStar rated to get the tax credit.
Good luck!
Norb

[Mark Circo]

Norb
That is the same unit I am looking at. Am I correct it does water to air and water to water. So that I may use the same geothermal loops for A/C and hydronic radian heat?

[Norb]

Mark,
Yes it will. It gives you very economic, forced air -- air-conditioning in the summer and hydronic radiant heat in the winter. It can also give you a fast forced air heating cycle; then switch to hydronic radiant for temperature maintenance. You dial up your furnance from remote and turn the forced air heat on while you are traveling to your log home, then switch to pure radiant when you arrive. You can also buy an electic back-up system for the Synergy if you want the security.
Regards, Norb

[Log Guy]

I'm not the sharpest tool in the shed, but I've researched the conductivity of aluminum (used on Warmboard) and concrete (used in traditional radiant systems).  If what Warmboard uses is pure aluminum the k constant (a measure of a material's conductivity) is 237 (120-180 for alloys).  For concrete it's 1.7.  It seems that Warmboard makes more sense, especially since it doubles as the subfloor.  Additionally since most builders use 5/8" or 3/4" subfloor, you're also coming out a little ahead there as well.  Probably worth the $200/4x8 sheet.

[shanny]

If a home is efficient enough, there is really no need for $200.00 a sheet subfloor.   Thats not for the average person.

 I do realize that log homes have drawbacks sometimes....in a conventional structure you can increase insulation capacity in using foams which make for a very livable / comfortable space.

In Maine, there are more and more homes going radiant slab heat...some really like it and others are dissapointed (bad installs etc.).   But it is really cheap to put PEX in a slab that you are going to pour anyway (Basement as an example), and makes for quite a heat sink once its operating during the middle of winter.

Like anything, it has to be done correctly.

Here is an excellent design guide from First Nations Canada for frost protected slab construction.  The use of PT ply as forming and plate casted into the slab is excellent idea.  If Iwasn't going with a small basement, I would do this design and cast PEX in the slab.

I would build a PT stick knee wall (12-18" off slab) and start logs from there.  You could also use this as a wiring chase. 

[shanny]

OOOPS......here is the link; ftp://ftp.cmhc-schl.gc.ca/chic-ccdh/Research_Reports-Rapports_de_re....

 

Lowes sells Avantec for $27.46 a sheet, and 3/4" T & G OSB for $11.86.

Home Depot has a similar product called advantage subfloor, which runs about $15 and some a sheet.