Our mechanical engineer just recommended a fhp ww072 6 ton heat pump (water to water) for our radiant heating a single story 3000sqft new house. Wondering if anyone has any experience with this heat pump?

A proper installation done by an experienced installer is more important than a brand name.
Choose your installer carefully and ask about warranty details.

Did your mech E perform a load calculation in compliance with ACCA manuals J and S before making that recommendation?

Ask him or her why FHP over Water Furnace or Climate Master.

I second the statement that the quality of the design and installation trumps brand issues

Will ask the questions and get all the load calc's/heat loss stuff early next week. Wondering what are the differences between the various brands, Water Furnace/Climate Master, etc.....

Differences are minor.
Warranties can vary (your installer plays a part in the warranty).
Two stage compressor can improve efficiency since loads are a moving target (referring to seasons).

The manufacturers web sites have manuals posted on their units. You can take a look to see the differences in features and efficiency.

Nearly all the two stage high-end units use Copeland 2 stage Ultratech compressors and similar peripherals so brand-to-brand differences are generally minor

A heating-only radiant system with a reasonably decent sized buffer tank may benefit less or none at all from a 2 stage unit.

A heating-only radiant system with a reasonably decent sized buffer tank may benefit less or none at all from a 2 stage unit.


Agreed - but with GEO W to W one should take advantage of cooling use also.

Posted By geotek on 15 Mar 2010 10:08 AM
A heating-only radiant system with a reasonably decent sized buffer tank may benefit less or none at all from a 2 stage unit.


Agreed - but with GEO W to W one should take advantage of cooling use also.

If cooling with hydronic fan coils, buffer tank is still employed and 2 stage unit may still not have big advantage.
j

Thanks for all the information. I will have a meeting hopefully this week to find out the details of the recommendation. I'm sure this is a heating only location, jackson,WY, I know he was looking at the largest single stage pumps and came up with the 6 ton fhp, then mentioned he found a 10 ton. These seem pretty large to me, and said the cost is only 6K and 11K, that seems low to me with all the mentions on this site being in 25K+ range for smaller systems. More later.

Meeting is next week, but I did find out he wants to use a 10 ton unit now and 30 gpm instead of the 6 ton at 14 gpm. Basic difference is I want to put the pex tubing in my garage so I can melt the snow off the cars in the winter but basically keep the temps around 40 in the garage. Well water temps are cold, some say 41-42 degrees, others say 47-48 degrees, how much does that matter. Either of these units seem large, with the 10 ton being way over the top to me. I'm putting in R40 walls and R60-70 roof insulation so the envelope should be good. They think there should be adequate heat. Will get the raw numbers next week. Just want a ballpark are these units large? and will they last? or require maintenance due to water quality issues.

Yes X 3.

Once you have a heat loss calc, we will be able to answer your questions about size.
Regarding price, there is a big difference between off the rack and installed pricing. There is also a big difference between the cost of open and closed loop installation cost (could be more than $10,000 on a 10 ton).
j

Heat Loss was calculated at 105,000BTu/hr and the 6 or 10 ton unit, with lots of supplemental heat in various rooms. We get days/weeks of minus 0 temps, so the effectiveness of geothermal in my opinion is limited. The payback period was at least 11 years, so we decided to go with a electric boiler and put more money in the envelope than the system heating it.

in my area 105kbtu would suggest ~6 tons. When you say pay back was at least 11 years that is assuming anything else you install owes you nothing. Everything else is a loser and geo ECLIPSES them in ~11 years.
Problem here is your designer doesn't seem to know geo either.
J