I'm looking seriously at using this unit for my radiant floor heat & domestic water heating app.  Anyone using these WW units, these are the ones using 410A refrig.

Thanks for any info!

I'm sorry, but no time to down load, what are specs and max. temps of WW. What temp was your in floor radiant designed at?........

Looks like it max will produce 125 deg or so - max the radiant floor needs is somewhere in this range 125 - 135 under design conditions. We added insulation this year, under the floor and in the house envelope, so 120 - 125 may just do it.

I can go with one of several brands of water to water heat pumps, looking at the COPs they are mostly in the same range.

Now I'm starting to focus in on reliability. FHP, Waterfurnace have pretty decent looking R410a units, GeoComfort has been mentioned - also a 410a unit,  Climatemaster is R-22, except the new 145 deg unit I mentioned on the other thread...this is one to watch but it may be too new to know much about its reliability?

Any input on reliability of these or other brands of water to water heat pumps will be appreciated!

The thing that occurs to me is that these are high temps for geo. The R-22 Climatemaster does not necessarily promise to achieve 125. Is this a new build (can we change pipe density)? Or retrofit (in which case I think you have to look at the new Climatemaster). Entering water temperature obviously affects the output temp. I seriously doubt the promises of most units to produce consistantly 125 degree water (particularly in northern climates). I'd like to see more info on your geography and btu load. I'm worried that you may not be pleased with your results if someone is running a 135 degree floor on a conventional water to water geo.
Joe

Hi Joe,

Thanks for your ideas,they are helpful. The radiant floor system is existing. It would be possible, but a big project, to add tubes. It is a staple up, one tube per bay, with alum. heat transfer plates. Last year I added a few tubes to impove the density at the perimeter, and I added plates to any uncovered area. I am adding to the insulation below the floor now. We improved the envelope insulation last year as well. So...we will have to see what temp is now required after the improvements. It may be that 120 deg is enough in coldest weather (it may want 135). Most of the season 90 -110 will be enough.

The new CM would be a good solution, as it could run at the lower temps most of the season, and still have the headroom to take care of the cold spells. It is worth considering.

I guess the other possibility is if we went with a unit that can't sustain as high a temp as needed, next summer I'm back in the basement adding tubes and plates to the radiant floor! Joe, you're helping me think this through... I sent out some more feelers to see what more I can find out about the CM THW, and if any are installed around here. I'll post if I learn anything significant.

I have a FHP WW036 w/o DSH that is on 3-200Ft vert loop. It is now into the second winter. My bad for not buying an WW048 machine. The heat calc indicated a 36k BTUH load and for R22 the WP 036 machine is rated 36000 BTU/H.
The rub comes when the identically labeled WW 036, an R410 machine is only rated ~28000, leaving me short on summer capacity.
It was shipped w/ a WP 036 manual and a R22 HP cut-out switch. FHP promptly sent the correct switch and the machine would then run fine just needs the full 3 tons of capacity.
EWT is ~high 80s in cooling mode and produces 44 F to the Supply Tank which feeds a Water Coil Air Handler.

The machine is fairly well made, uses a Copeland scroll compressor and is quiet enough even though it is directly under my bed. Internal insulation is not complete enough to not sweat in the cabinet. Everything is insulated EXCEPT the dryer and reversing valve which is just too much exposed metal. I must add either strip foam like the rest or spray foam or the cabinet hardware will not see the compressor warranty to the end.

I considered adding a DSH to reduce the kwh $$ for DHW heating but the system won't stand any more capacity loss.

It will keep my 2080 sf ranch @ 79 F Ok but not 78 which is needed to entertain w/ several guests in summer.

Heat is about 1/2 radiant and 1/2 forced air. I maintain 69 F with no problem and some left over to heat a 1200 sf garage w/ radiant.

Make your selection on capacity from the charts and ignore the nameplate and things will go fine.

Dick

The formal name for that suggestion / procedure is ACCA Manual S.

FWIW Waterfurnace Envision with DSH provides handy-dandy switch to stop DSH if needed in winter - easy to dump DSH on or about Christmas Eve and restart it on Valentine's or St Patrick's Day after the worst of winter has passed. An even more elegant soultion would be to automatically dump it if in heating mode and Y2 is active

Not sure I've ever seen a unit with insulation on the reversing valve. (Liquid line) dryers are not normally cold?!?!

In Cooling Mode the whole load side loop is cold. This yields condensation on the dryer and 1/2 of the Reversing Valve.

Forgot to mention I'm in N. Georgia

Craig,
I wanted to ask you what is the max heating temp you can get in the buffer tank?

I have set it at 105F for two reasons.

Lower temp = lower kwh / less work for heat pump / longer life

Lower temp = better protection for tile floor from cracking. Delta-T in the radiant loops is about 8F, AH loop is abt 12-15F.

Tile is over 2" of concrete which is over poly barrier and then original wood house. I had worked out where to put expansion joints in the concrete and installed them. The joints did not get put into the tile so it made it's own in a place or two. They are straight enough that I haven't gone back and sawed them yet.

I did add staple-up plates to the master bath but have not tested them yet. It was into cooling season when I finished it up.

I reused the old ductwork for the most part. The house is divided 1/2 tile, 1/2 carpet so I heat the carpet 1/2 via forced air with dampers to shut off the tile 1/2 in heating mode. By leaving all the Returns open it is amazingly well balanced.

Dick

sounds like a nice system Dick. I am concerned with getting higher water temps in colder wx as my radiant floor is staple up. I will be using an AHU as well. Glad to hear you are getting a good delta T with only 105 deg water on your AH. I'll be happy if I can achieve that too. In NH with some cold winters.

I used the 12-inch J-M poly wrapped fiberglass for floor insulation. In your climate I would use the spray-on for the perimeter then the thickest fiberglass your joists will accommodate. Regardless of initial temp the heat will go in the direction of least resistance. Good insulation is a must to drive heat up where you want it instead of elsewhere/ down.

The insulation can be R & R if you find some parts need more plates/loop to get you warm. An IR Thermometer is a good investment to know when you are making progress.

Minimize the rugs/ carpet too.

Dick

thanks Dick, yes I am considering doubling up on some of the tubing, with new plates as well. This would bring down my loop temp requirements. Last year I added new perimeter tubing, going through the joists around perim, was hard to pull but filled in where more heat was needed.