I’m trying to follow the beestat guide to optimize my heat pump system and I feel as dumb as a box of rocks. I may be overtired.
Can someone explain it like I am 5 how to get my Balance Point? Our house has 2 ecobee3 lite thermostats.
Balance point = The outdoor temperature where the orange line crosses the x-axis. In your case, it’s not visible on the chart. If you use the Heat line equation that’s:
y = mx+b
We want where y = 0, and to solve for x, so
(y - b) / m = x
(0 - b) / m = x
We know m = 0.0189, b = 1.9617
Plug and solve
x = -103.8°F
Congratulations, your heat pump cares little about thermodynamics.
Do you happen to have a gas furnace instead of a heat pump?
Oh, if you have two thermostats then you have to take the profiles with a grain of salt. In a zoned system, the beestat profiles only collect data for a zone when only that zone is active. That prevents bleed as air moves between zones.
An upstairs zone is almost always going to have a very effective-looking profile. Heat rises, and upstairs zones are often smaller in volume than downstairs ones, so it’s entirely possible the upstairs zone has a profile like yours.