Staple Up vs Gypcrete

NJ, Designer

I was in court today defending a GC being sued by a home owner he just built a house for paid in cash $2.6 million...
the fight is if he over charged for the geothermal job...... there were two geothermal experts in court one on the defense and one on the offense. the homeowners geo expert, that didn't do the job said it is overpriced, after going through his estimate it was revealed that it did not include the cost of pouring gypcrete for 8000 SF, So the argument started why use gypcrete and not staple up. well obviously I said that in a staple up the water runs hotter (not as efficient) and its not as even (comfort) and not as stable...... I was not prepared for this argument as I was always taught gypcrete is far superior than staple up, and never had to argue about it. Does anyone have some good documentation to help me drive this home....? or I am wrong?

Thanks

hot_rod

There is some excellent information in this journal showing efficiency, COP and the importance of low operating temperatures. It does go into detail about slab and gyp being two of the best matches for GEO.

http://www.caleffi.com/sites/default/files/coll_attach_file/idronics_9.pdf

kcopp

Not sure about documentation but a drawing would suffice.... There is a lot more surface area contacting the floor w/ gyp than w/ staple up. More heat transfer area= lower water temps= greater efficiency.
Sounds like a total BS court case.

Zman

What kind of staple up are you referring to. Plateless?

Rich_49

What County is this being heard in NJ ? I would love to come watch this . Would some radiant panel reports from another home using both methods help ? Interesting stuff

Zman

Siggy probably is the best source.
http://static1.squarespace.com/static/50de4c94e4b0a05702aac0fb/t/510c2fd0e4b08258fab476e5/1359753168007/ShakeoutTime.pdf

Also look for his "Plateless in radiantville" article.

Rich_49

Here are 2 more , same house with concrete overpour and lightweight overpour . hell all 3 are here . Please delete any of my information from the reports . You may also want to mention that Hp COP is the biggest issue and many water to water heat pumps start to degrade rapidly over 100*F

Gordy

Also look at the heatloss of said home. Staple up may not have even been able to supply enough btus per SF plated or not at a water temp conducive to geo.

NJ, Designer

Well firstly thanks all for the help,
I am pretty sure is was plateless, and this is in ocean county, not exactly sure but It was a arbitration....
This other geo guy also always as a standard supply's 2 stage heat pumps????? and gives estimates by the square footage on the fly includes HRV's but rarely has to modify his charge.... any professional knows this guy is a snake oil sales man but I need to convince this arbitrator, not sure how much he knows about geothermal.....

hot_rod

Sounds like it will come down to what the arbitrator understands or is willing to learn about heat loads, proper design, etc.
As you know that's a lot to understand or learn.

Often times they end up "splitting the difference"

Rich_49

Nj Designer please contact me privately . I am in ocean County and have data on folks who have installed bad Geo systems on the load and source sides . If for no other reason I would like to keep my data current .

Dave H_2

It all comes down to the Math. Yes both types of radiant will work and there is, in the homeowners mind, no difference. Radiant floors is radiant floors.
Its when it gets down to the mechanicals and do you have enough water temperature and BTU's to satisfy the heat loss.
Typically, gypcrete radiant floor applications run a much lower water temperature than a suspended tube application.
The heat loss numbers will tell you what water temperature is needed for each style of radiant floor application.
In my experience, when using a water-to-water geo system, gypcrete style radiant floors is the direction needed because of the limitation of the water temperature that can be achieved.

Snowmelt

That is very interesting post.