What is this water...?

[Kenneth]

Howdy,

We heat one of our buildings with a 4 ton water-to-air heat pump, and it has worked very well for the past seven years. In the winter, we pipe steam into the duct system to humidify the building.

The heat pump has a small drain that empties into a pump that (during the AC season) moves the condensate from the unit into a slop sink in my shop.

Yesterday, in the cold of our New Hampshire winter, I was surprised to hear the sink gurgle as about a pint of water drained.

I watched as it came out of the heat pump drain tube...

But, where would such water be coming from during heating season? It would seem that the would be no condensate, but what else would it be?

Many thanks for any thoughts,

[HVAC]

Defrost cycle?

[Kenneth]

Howdy,

Why would there be any frost if it is heating?

Thanks,

[Kenneth]

Hi again,

I know that if too much heat is extracted from the water (so that the coils start to freeze up) the compressor shuts down. In such a situation there cost be some frost, but our weather has been very mild.

Thanks again,

[Jim Dandy]

That is Holy Water from Heaven. Taste it- is like milk and honey (much like your old lady's milk when she is nursing little Kenny).