3 ms·
> That means the cost of your system will be approximately double to run what the manufacturers specifications claim. Wait, seriously? That's (a) disappointing
by orra 4y ago
> That means the cost of your system will be approximately double to run what the manufacturers specifications claim.
Wait, seriously? That's (a) disappointing, because I thought heat pumps were pretty great. And (b) you're absolutely right: it's misleading advertising.
- londons_explore 4y agoTypically these systems underperform because they are tested in ideal lab conditions, but then the actual installation has lots of non-idealities (long pipes with lots of bends, dirt, dumb thermostats, wrong flow rates, poor airflow, blocked filters, things cycling on and off, etc). The full report that the (uncited!) diagram is from is here: https://acep.uaf.edu/media/290488/Air_Source_Heat_Pump_Potential_Alaska.pdf https://acep.uaf.edu/media/290488/Air_Source_Heat_Pump_Poten... The report describes a few other heat pump models which do meet the advertised specs.
- orra 4y agoThanks, that's reassuring.
- silverlake 4y agoThanks for the link! I have Fujitsu which I run when outside air is above 40F. Looks like it gets an amazing COP of 5 to 6, far exceeding the spec. I have tankless hydronic heating using natural gas for most of the winter, but it couldn’t quite heat my house when temps dropped to 5F.