Please forgive me for not doing all of my research first but i have a slow computer and am running short on time!

So far, over the last 10 months ive built a 1700sf 8" ICF basement w/50sf glass, 1700sf 6"ICF main floor, 300sf glass with 450sf garage, vaulted ceiling and hollow core concrete plank floor.  I've managed to design and build just about everything myself in my evenings, weekends and vacations working through a MN winter (fun!).

Planning on geo-thermal heat pump w/radiant floor heat, 2" gypsum or similar topping on main floor and 4" slab over 2" HD insulation on grade for basement and garage. Ill be demolishing my old house which is right behind the new one and will leave a giant 7ft deep hole from the old basement for the ground loop.

I just posted in radiant heat for advice on installing my floor heat which i need to get done in the next week or so to enable me to carry on with construction.  Right now im looking for some Heat Pump quick advice. Both floors will be radiant floor heated, im planning on forced air for A/C, the house is basically a 50ft square with a vault down the middle, very simple.

Normally i would spend many weeks researching each step but for reasons i wont go into, i cant right now. Im looking for quick advice on types/maunfacturers of heat pumps, how best to install, how to select/size, layout etc. Helpful tips, hints or advice, what to do, what not to do, what to avoid, reliable sizing guides etc.

Please dont tell me to hire a contractor (i'd love to) because its unfortunately just not within my budget or time frame. I do have free access to a commercial HVAC contractors design and engineering dept but doubt they have geo experiance.

Ive found this forum very helpful so far with my ICF design and construction.

Thanks in anticipation for your help and advice.

Peter

i would just put in an air source heat pump. with an icf and radiant heat you are getting into diminishing returns.

Start with a load calc. $50 gets you temporary use of HVAC-CALC, a $389 software package. You need both Manual J and D design info.

Unfortunately you seem to want to violate this timeless rule: "Good, Fast, Cheap - pick any two"

Load calc will give you tonnage needed winter and summer.

Major geo brands sell systems doing what you want, and you could probably work out installing one assuming you come up with a good radiant floor design as well as the J&D calcs I describe above.

In you shoes I'd hire a geo loop designer - that end is just too easy to screw up and kilobuck$ to retrofit.

Really you need a pro to take responsibility for the whole system. Try to find one that will let you participate via sweat equity. There is still then the question of permits and ultimate legal responsibility for safety and efficacy of the result.

ditto engineer.
we don't know requirement and therefore can't suggest much except, get more advice. my current homeowner/GC has cost himself 8+ grand in heating system changes so far (I say this with frustration not a smile) and about a year in build time.
good luck,
Joe

I would do radiant floor for comfort, not the minor energy savings.

The radiant floor heat is for comfort more than anything, if i can make it work with a GHP system it makes sense because its a new install rather than a retrofit so my payback will be shorter.
Ive gotten some feedback on laying the pipes for the 1st floor, in the meantime i will pursue heat loss calcs required to size the heat pump.

I also have the option of hooking up the furnace from my old house which is only 2 years old to me new Ac ductwork as temporary heat till i figure out the GHP.

Thanks so far for the advice.

Peter

GSHP can work very well with in floor radiant but not if improperly designed. Maximum temps achieved by a closed loop in system in January are not as high as a boiler can get so tube density may have to be greater (spacing narrower).
j

Also have to beware of room loads and insulating value of floor coverings on radiant floors - wall to wall carpet with a pad beneath presents a design challenge, especially in light of the lower water temps available from geo systems

The success of your radiant install will hinge on the effectiveness of your thermal break around the at-grade slab perimeter. Get that right or you can't fix it afterwards.

Design and install a thorough grid of expansion joints in your slabs. You will be disappointed by the cracks otherwise.

Limit each loop to about 200 L Ft and make all loops the same length within 10 ft so it is self balancing.

Be conservative that the amount of in-floor tubing is adequate. You can always adjust downward w/ temp and flow but you can't add anything to speak of.

Most of the literature says 6-inch spacing between tubes at the perimeter increasing to 12-inches in the middle. Six-inch spacing is about as hard as you can drive heat through concrete anyway.

Read the material from:http://www.pmmag.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2379,5132,00.html

and search on a guy named John Siegenthaler to get up to speed.

Radiant heat won't just rise naturally, rather it will go in the direction of least resistance. This places a premium on proper under slab insulation design and installation both at grade and elevated.

As has been stated water temperatures in the high 90's are all you will realistically achieve w/ a GSHP so work up your grid accordingly and compare with the Manual J loads.

Draw up your grid, do the calculations and adjust as necessary then faithfully stick to your dimensions during the install. Zip-Tie the PEX to a rebar grid on chairs to get the PEX 2-2 1/2" above the bottom of the slab.

Dick