We have an air source heat pump and I’ve managed to get data out of it so that I can link it to Home Assistant.
I’ve noticed that, on sunny mornings, the displayed ambient temperature is significantly higher than the actual temperature.
I’ve just had a hunt for the sensor and it’s above the garage door, on a roughly east facing wall so it spends a lot of the morning in direct sunshine.
I’ve not had much success on Google, but this doesn’t feel right as it would need to be in the shade to provide accurate ambient temperature readings. Is it something about which I should be concerned?
With my engineering head on, I would be inclined to think that a sensor measuring X should be situated so that it reads X without being exposed to anything that could skew that reading.
Blimey! I didn’t realise those enclosures were named or who their inventor was and I should’ve known as I spent 20 years working with various Faraday cages.
After a frantic Google, that could work or I could just move it from the front to the back. Bizarrely, that’s a lot closer to the heat pump and would have used a lot less cable, plus being in the shade.
When the sensor is in direct sun, it will record a temperature that is far higher than the actual air temp. That will then cause your system to start cooling - possibly fairly aggressively - when that is almost certainly not needed for much of the time.
Ours is on a north facing wall, in shade for most of the day, except early morning as the sun rises. Not really a problem in winter when we need it most, and responds well to the “inter-saison” where temperatures fluctuate quite significantly during the day.