System is a 3 ton WF Envision installed late last summer.  Have a unonpowered 80 gal buffer tank in the loop with the desuperheater (DSH).

During this past winter I had on avg a $2.50 bill for hot water each month.  The loop (cold inlet and the bottom drain) at the buffer tank would get hot.  The outlet of the buffer tank (red left connection) would only get hot when hot water was used in the house.  Operation normal.

Summer arrived this weekend here in Wash DC  ;)  AC has been running and while the loop on the buffer tank is warm but not hot like in winter mode.

Is this to be expected?  As a homeowner I would think it would be the opposite.  In summer mode the DSH is helping to extract heat by running it in the buffer tank which is fairly cold city water. 

CH

Your unit sounds like it may be the same as one of our units. We have similar domestic hot water results in cooling mode. The maximum temperature of the DSH is greater in the winter(others can technically explain this better than I can.) Also, our geothermal (and DSH) run time is much greater in heating mode, thus producing more hot water. Even though your system is cooling now, I would expect it to run much more in the summer months and produce more hot water for you. Not much hot water benefit in the shoulder months.

Entering water may be quite cool early in cooling season. That's excellent for air conditioning efficiency but doesn't provide much higher grade heat for domestic hot water.

I'm impressed by the $2.50 / month hot water cost in winter. How are you calculating that?

As geome suggests, you will see much more contribution as you get deeper into the season.
j

The hot water heater is not electric.  Some of that $2.50 could be for the kitchen stove but it's not used much.   It's only two of us and with all the snow we had not many relatives came to visit  ;)

CH

CHuntMD,

We have read your comments regarding your desuperheater.  You are correct.  There is a greater hot water benefit during cooling because some of the heat that is extracted from the air ends up in the superheat, and is transferred to the water.  On very cold days the desuperheater could generate more hot water required for the home due to the long run times of the unit.  However, on milder days when the unit has short duty cycles, the electric elements in the water heater will maintain the desired temperature so there will always be enough hot water for the homeowner.

WaterFurnace International, Inc.