John Siegenthaler: System designs need numbers to guide decisions
Numbers inform design
I’ve written several “Heating with Renewable Energy” columns covering the benefits of combining modern hydronics technology with modern air-to-water heat pumps.
One of the two most salient points stated in all those columns was that the heating output of any air-source heat pump decreases with increasing water temperature and/or decreasing outdoor temperature. The other was that the heat pump’s coefficient of performance (COP) always increases as the temperature at which the hydronic distribution system operates decreases.