IMC TRANS DC power and REFCAV TRANS DC power are oscillating every ~15 mins as we can see on StripTool in the control room (first attached plot). We suspected that is from the subtle (~1 deg C) oscillation  of the temperature (humidity) in the PSL room. The second plot shows the coherence between those chans and the temperature/humidity. They are obviously correlating. Note that temperature/humidity sampling is 60 sec.