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ronbo · 10-21-15, 04:52 AM

Warning... Newbie question...

Currently on 11th year of a Trane XL14i ASHP. Only mod so far is the addition of a HyperEngineering SoftStart Sure-Start compressor starter. I was having problems with compressor startups on very hot days (thermal overload shutdown, was trying to draw over 70 Amps on hot-startup), this seems to have solved that issue.

My Winter performance is pretty fair, I've had it run in heat-pump mode down to under 20°F, and still keep up... though it was running at 100% duty cycle. (and I'm not sure I'm getting any more than a COP of 1 when it's that cold)

Just some random thoughts... would there be any benefit to wrapping "pipe heater tape" around the cool liquid return line from the house (after heat is removed), prior to the outside condenser coils... to help prevent coil freeze-up?... or even to extend the lowest running temperature...? (applying AC power to it by a simple OAT thermostat at <30°F or so, and only when unit is operating)

I know there is still some heat "out there" that can be pumped into the house, but it's insufficient to do the whole job... so it shuts off and runs aux heat (natural gas furnace).

If I add 300 Watts to the refrigerant line before it goes through the outside condenser coils, I know that heat will be pumped indoors along with the heat gathered from the outside ambient air, but will it be on a 1:1 ratio?

Even at that, it seems it may still increase its ability to run at lower temps... prevent coil freezeup and defrost cycles, and therefore still utilize the 'free heat' from outside air longer, and defray running the gas furnace.

I have other 'mod' questions... but this one popped up first...

10-21-15, 04:52 AM	#1
ronbo Lurking Renovator Join Date: Oct 2015 Location: Kansas City, MO USA Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts	ASHP mod question Warning... Newbie question... Currently on 11th year of a Trane XL14i ASHP. Only mod so far is the addition of a HyperEngineering SoftStart Sure-Start compressor starter. I was having problems with compressor startups on very hot days (thermal overload shutdown, was trying to draw over 70 Amps on hot-startup), this seems to have solved that issue. My Winter performance is pretty fair, I've had it run in heat-pump mode down to under 20°F, and still keep up... though it was running at 100% duty cycle. (and I'm not sure I'm getting any more than a COP of 1 when it's that cold) Just some random thoughts... would there be any benefit to wrapping "pipe heater tape" around the cool liquid return line from the house (after heat is removed), prior to the outside condenser coils... to help prevent coil freeze-up?... or even to extend the lowest running temperature...? (applying AC power to it by a simple OAT thermostat at <30°F or so, and only when unit is operating) I know there is still some heat "out there" that can be pumped into the house, but it's insufficient to do the whole job... so it shuts off and runs aux heat (natural gas furnace). If I add 300 Watts to the refrigerant line before it goes through the outside condenser coils, I know that heat will be pumped indoors along with the heat gathered from the outside ambient air, but will it be on a 1:1 ratio? Even at that, it seems it may still increase its ability to run at lower temps... prevent coil freezeup and defrost cycles, and therefore still utilize the 'free heat' from outside air longer, and defray running the gas furnace. I have other 'mod' questions... but this one popped up first...