In the last few weeks, I've had one or both of those fail to apply on the majority of nights. Dropping to 65F doesn't help when the outside air is also at 99% humidity. If the overnight low is 75F, we're not getting much cooling out of it.
Any system has to deal with time-variable conditions.
I dream of getting a geothermal heat pump for my 1850s farm house which is normally heated with two wood stoves but has a propane backup. (e.g. the kind of compact heater that you see all the time in people's apartments in anime)
At points south the capacity of that kind of system is set by cooling demand but where I live it is set by heating demand. The woodstove could pick up the slack on the coldest days, but that defeats the main selling point of the heat pump which is extreme comfort (e.g. it switches seamlessly from heating to cooling)
Between pollen count and pollution this is not always the case, and keeping the windows closed and running both the AC and an air filter unfortunately has health benefits for some individuals.
- the humidity has to be comfortably low
- the outside temperature has to be low enough
Historically, this is usually the case.
In the last few weeks, I've had one or both of those fail to apply on the majority of nights. Dropping to 65F doesn't help when the outside air is also at 99% humidity. If the overnight low is 75F, we're not getting much cooling out of it.