Direct_Rabbit_5389 t1_iqqqdlr wrote
Reply to comment by arfbrookwood in Shocked by gas bills, thrifty Dutch stockpile coal, wood for winter by clampie
It's not about the size of the pump, it's about the chemical technology used. Newer chemistries stay efficient to lower temperatures compared to older ones. Some are even efficient down below 0F.
(Conversely, a larger pump may not even help if you have a really old chemistry. Your pump would have to switch to backup resistive heat at the point where it's chemistry stops being efficient.)
hirsutesuit t1_iqr0ac2 wrote
Mine is still 100%+ efficient at -22F (-30C).
Direct_Rabbit_5389 t1_iqx55cf wrote
100% efficiency is a given -- resistive heating is 100% efficient due to the first law of thermodynamics. The important cutoff is when the heat pump becomes less than 400% efficient, or when the heat pump becomes less financially efficient than a gas furnace.
hirsutesuit t1_iqxpfjl wrote
No, it's not. The percentage would be different for everyone - and it could change everyday.
If you don't want to set things in fire in order to keep your house warm then anything more efficient than resistive heating is good.
Viewing a single comment thread. View all comments