defrosting a heat pump -are there any tricks?

ecomodmonster · 11-23-21, 07:30 AM

Hi

i have a portable heat pump air conditioner which i am using to heat my house.
when its really cold it spends half the time switched off and defrosting.

i was wondering if the more expensive heat pumps have any advanced features for defrosting?
my heat pump just switches the compressor off to defrost and waits for the frost to melt.
do any heat pumps use water to defrost? or electric? or would that be heating the outdoors and poor efficiency?

Acuario · 11-23-21, 12:42 PM

The normal method is a hot gas defrost. Basically the refrigerant flow is changed so hot liquid refrigerant flows to the condenser instead of cold liquid, this then defrosts the condenser in 'super quick time'. Normally it is a fixed time defrost that is run when a designated temperature is reached or exceeded for a set period of time.

The split type a/c units turn off the interior fan while defrost is active so the user doesn't suddenly get a blast of cold air.

On my own controller I monitor the temperature of the condenser so can cut short the defrost cycle if necessary.

ecomodmonster · 11-27-21, 06:23 PM

are there any portable heat pumps with that feature?

Xringer · 12-21-21, 10:24 PM

When it's really wet and then gets down in the 20s F, my heat pumps will go into defrost mode.
The heating mode switches to cooling mode, but the indoor air handler fan will be off or very low. So as not to cool off the house.
That works really well when the ice isn't too thick..

So sometimes, when there is a lot of ice on my main house unit, and I want get rid of the ice faster. I'll change to mode to Cool the house! The living room gets pretty cool, (we wait in the den, where it's warmer). After 10 or 15 mintues, I turn if off, and wait for more melting.
Many times, I'll watch the ice on a security cam located in back of the outdoor unit.
I leave the unit off until the ice is pretty much gone off the warm HX coils, and return it to heating mode (66 or 67F) and go to bed..

11-23-21, 07:30 AM	#1
ecomodmonster Lurking Renovator Join Date: Sep 2012 Location: England (stoke) Posts: 14 Thanks: 0 Thanked 2 Times in 2 Posts	defrosting a heat pump -are there any tricks? Hi i have a portable heat pump air conditioner which i am using to heat my house. when its really cold it spends half the time switched off and defrosting. i was wondering if the more expensive heat pumps have any advanced features for defrosting? my heat pump just switches the compressor off to defrost and waits for the frost to melt. do any heat pumps use water to defrost? or electric? or would that be heating the outdoors and poor efficiency?

12-21-21, 10:24 PM	#4
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	When it's really wet and then gets down in the 20s F, my heat pumps will go into defrost mode. The heating mode switches to cooling mode, but the indoor air handler fan will be off or very low. So as not to cool off the house. That works really well when the ice isn't too thick.. So sometimes, when there is a lot of ice on my main house unit, and I want get rid of the ice faster. I'll change to mode to Cool the house! The living room gets pretty cool, (we wait in the den, where it's warmer). After 10 or 15 mintues, I turn if off, and wait for more melting. Many times, I'll watch the ice on a security cam located in back of the outdoor unit. I leave the unit off until the ice is pretty much gone off the warm HX coils, and return it to heating mode (66 or 67F) and go to bed.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

11-23-21, 12:42 PM	#2
Acuario Apprentice EcoRenovator Join Date: May 2011 Location: Tortosa, Spain Posts: 221 Thanks: 2 Thanked 81 Times in 46 Posts	The normal method is a hot gas defrost. Basically the refrigerant flow is changed so hot liquid refrigerant flows to the condenser instead of cold liquid, this then defrosts the condenser in 'super quick time'. Normally it is a fixed time defrost that is run when a designated temperature is reached or exceeded for a set period of time. The split type a/c units turn off the interior fan while defrost is active so the user doesn't suddenly get a blast of cold air. On my own controller I monitor the temperature of the condenser so can cut short the defrost cycle if necessary.

11-27-21, 06:23 PM	#3
ecomodmonster Lurking Renovator Join Date: Sep 2012 Location: England (stoke) Posts: 14 Thanks: 0 Thanked 2 Times in 2 Posts	are there any portable heat pumps with that feature?