EcoRenovator - View Single Post - Propane (R-290) for heat pumps?

Xringer · 07-11-11, 01:20 PM

I was just thinking about how to make one of these..
The problem of cold weather freezing the in/out H2O pipes solid is a major worry.

Idea #1.
Heating wire under the insulation, controlled by a freeze sensor.
(I have some of these installed indoors already).

Idea #2.
Plan A is to circulate the ASHP hot water inside, into the water-jacket of my HS Tarm boiler.
I would use the existing (downstairs) baseboard circulator pump.

This pump would be controlled by a differential? control box, with a freeze detect mode.
I think the control box should be 'smart', using a timer with an on-demand mode.
I figure keeping the boiler above 90F at night would be ok..

If the outdoor coil got down near 38F, the pump would turn on and dump some warm
water into the outdoor coil. Until it warmed up..

If it got down under 10F for a long time, (ASHP could not be used) the oil burner
could be used to keep the water jacket warm. (Or, I could toss in a log).

07-11-11, 01:20 PM	#59
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I was just thinking about how to make one of these.. The problem of cold weather freezing the in/out H2O pipes solid is a major worry. Idea #1. Heating wire under the insulation, controlled by a freeze sensor. (I have some of these installed indoors already). Idea #2. Plan A is to circulate the ASHP hot water inside, into the water-jacket of my HS Tarm boiler. I would use the existing (downstairs) baseboard circulator pump. This pump would be controlled by a differential? control box, with a freeze detect mode. I think the control box should be 'smart', using a timer with an on-demand mode. I figure keeping the boiler above 90F at night would be ok.. If the outdoor coil got down near 38F, the pump would turn on and dump some warm water into the outdoor coil. Until it warmed up.. If it got down under 10F for a long time, (ASHP could not be used) the oil burner could be used to keep the water jacket warm. (Or, I could toss in a log).