Latest revision as of 21:01, 20 November 2020

Basics

A heat pump - using air heat exchange - extracts heat or cold from the ambient air. There is an outside compressor, and indoor heat exchanger. A split unit. Install requires placing the heat pump outdoors, and placing one or more heat exchangers indoors.

This one says that it's not worthwhile below 30F [1]. How to reconcile with manufacturer claiming -13F?
It seems to be that it works very poorly at the low temps.
- 32F, COP is 3 [2] but at 10F it appears to be COP=2.
- At -5F, COP=1.3 and it shuts down, for backup heat to take over.
Pioneer mini-split page says it works to 90% capacity at -13F! [3]. just try it.

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 =Working Doc=
-<html> ________________________________ </html>
+<html> <iframe src="https://docs.google.com/presentation/d/e/2PACX-1vRPSjCUM5s-lk-HrRuEeZSsXeW1g0Cf7ir1jz_4p_vTgotql5yg0Y8KtIRAHr6TGTK-RFmC52nu34SP/embed?start=false&loop=false&delayms=3000" frameborder="0" width="480" height="389" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe> </html>
 [https://docs.google.com/presentation/d/15mYKFucL57P8U_dvaXIhAW36M7y_NE7EAeoDSx3XvC0/edit#slide=id.g5c3be0ce2d_1_28 edit]
+=Efficiency Vs Temperature=
+*This one says that it's not worthwhile below 30F [https://asm-air.com/heat-pump/what-temperature-is-a-heat-pump-not-effective/]. How to reconcile with manufacturer claiming -13F?
+*It seems to be that it works very poorly at the low temps.
+**32F, COP is 3 [https://www.nordicghp.com/2017/01/heat-pump-effective-temperature-range/] but at 10F it appears to be COP=2.
+**At -5F, COP=1.3 and it shuts down, for backup heat to take over.
+*Pioneer mini-split page says it works to 90% capacity at -13F! [https://www.pioneerminisplit.com/blogs/news/the-benefits-of-a-mini-split-system#:~:text=Low%20temperature%20heating%20has%20been,down%20to%20%2D22%C2%B0F.&text=Full%20DC%20Inverter%20technology%20allows,are%20qualified%20as%20Energy%20Star.]. just try it.
 =Internal Links=