Heating Help

Water temps gypcrete, warmboard, slab

@ May 21, 2010 11:46 AM in Water temps and costs different types of rad floor

ME thank you for your response.  We can just skip talking about prices if you want I can find those from the manufacturer.  You seem to be a warmboard advocate.  Given a heat load of 20 BTU per sq. ft. and the same finish floor covering what would you say the required water temps will be for gypcrete, warmboard, fined staple-up and in slab respectively.  Assume all reasonably insulated.  If you have a program or source for your information and you don't mind disclosing, I would like to check it out. 
I hope you can see what I'm trying to get at: the inherent efficiency of these different heating systems, in both BTU's and dollars.  Everyone cares about dollars and with low temp heat sources like GSHP and solar thermal coming on strong the required operating temp influences efficiency more than ever.
I feel that it would be a service to our industry to put together a cost and efficiency comparison like I'm talking about here.  That's what I'm about, when I come across an issue I feel I should, as a heating professional, understand, I try to put together an article. 
I like what you said about radiant ceilings.  That is another issue I would like to explore.  Thanks again for your input.  

Water temps and costs different types of rad floor

@ May 20, 2010 9:37 AM in Water temps and costs different types of rad floor

Thanks for your reply Chris.  My goal here is to get a general idea of the costs and water temps involved with different radiant floor systems.  I agree it is difficult but if we assume the same heat load on the room (20 BTU per sq ft) and the same finish flooring R value (R-1) insulate per standard practices (similarly in each case) we should be able to get an idea of the water temperatures required and be able to estimate materials and labor.  Of course there will be some variance in individual cases but if and when I complete this project I will make it available to others for their general education.  I'm sure you can commiserate with me when I say that not all sources of information agree.  Warmboard thinks their system has the lowest water temps and so does Ruapanel.  Different heat loss programs spit out different water temps, etc.  This is a problem in our industry and many others which have to deal with the real world.  We do what we can.

Water temps and costs different types of rad floor

@ May 19, 2010 2:24 PM in Water temps and costs different types of rad floor

I am trying to make a table which will list required water supply temps and cost for slab, thin slab, staple up and some of the other popular radiant floor structures (assume same floor covering and heat load).  I want to be able to give people a good general idea of what radiant floor system to use. Anybody know a good source for this kind of info? Have client building new house who wants radiant 2nd floor (wood framing, cold climate).  How do I choose between warmboard, gypcrete, subray, raupanel, staple-up etc?  Need to know costs and water temps, we want them both to be low. Any tips appreciated