Idea for solar assisted heat pump - Page 7

 
http://en.wikipedia.org/wiki/Heat_pump
Go down to Efficiency.
In a moderate climate they make better use of electricity than
resistance heating does. The initial cost is justified by using them
for summer cooling. I've heard that they aren't really cost-effective
in climates where the outside temperature stays below 45F for long
without a geothermal heat source. Around here it drops below 0F.

However if you have a solar collector to heat water, just use it
directly. My very simple collector made from scrap heats a laundry
load of water to 120F.

 
if you have a solar collector

 

Jim Wilkins wrote:


EROEI is in the region of 3 to maybe as much as 4 for the best new units in use
in Northern Europe.

Graham

 

Are those ground-source or air-source?  In Northern Europe I would suspect
they are ground-sourced to get that good a performance.

And ground-source installations aren't cheap. (but then neither is home
heating oil for those that use it)

daestrom

 

When the water freezes it looses a lot of heat energy (144 btu/lbm to freeze
water as opposed to 1 btu/lbm to cool water 1 degree F).  The freezer
'pumps' the heat energy out of the water and into the coil on the back of
the unit (in the room).  So that heat is added to the motor heat.

daestrom