Heat Pump Operating in AC Mode

[tact]

I am in the process of enlarging the return plenum filter area to 20"x20" to finally satisfy the airflow requirement for a 5 ton heat pump. I now have access to the evaporator coil and would like to do the foam cleaning from underneath the A-Frame. What would be the lowest ambient temperature for operating a heat pump in AC mode. I have temperatures near 60° this week.

[tritontr]

Are you using the foam cleaner that relies on the condensate water from the coil to rinse it?

[tact]

Yes. The product is CAL-SPRAY, http://www.acmeref.biz/public/acmepubli ... apfoam.pdf "evap foam no rinse" evaporator cleaner.

[tritontr]

It will produce more water if the air inside has a lot of humidity in it. The 60deg days would be better if it was raining out. As far as temp goes the lower the temp is outside the pressure in the system drops ( you know those gauges you always see us use) which can cause your coil to start freezing up once the temp-press relationship of the (coil) goes below 32deg. There are devices added to systems that allow them to operate in very low ambients but you would not have that on your unit . So 60deg is about as low as I would run it so you don't run the risk of compressor damage. In case your wondering your heat pump in the defrost mode is running in the A/C mode at low temps but remember it is for a brief period of time and the outdoor fan is not running which keeps the pressure in check.

[tact]

I lucked out today with 75° temperature and indoor humidity at 45%. I was able to run the AC for 30 minutes for rinsing the evaporator coil and later garden hosed the coil from underneath for a more thorough rinse.

[Robert]

Is it an upflow or downflow coil ?

We sell the coil cleaner here also.




Thanks,
Robert