I think if your air pump is pulling cold air into your brew constantly it will force the heater to run constantly killing Microbes.
I run a small electric room heater in small area pointed at my 5 gallon bucket and air pump. Keeps water and air intake warm.
As it gets colder I am going to bring brew into warm area for 27 hours. Im sure you will work it out.
tbh it was a rhetorical question meant for mm.
I use them in my teas when the ambient temperature is so cold it makes the environment counter productive.
there are concepts such as maximum efficiency, applicable necessity, and relativity which puts both realms into proper perspective.