Second guessing ERV

I've been a bit busy lately, so I've not had a chance to run the formal numbers... and there are a lot of variables at play, but...

My partner and I have noticed that the house is a lot drier this winter than it was last winter when we were alternating the HRV and ERV cores. A glance at the data suggests that the ERV does what it is supposed to do and helps keep moisture in the house during the winter heating period. I am planning to have a look at the moisture levels in the house between the ERV and HRV periods.

I've attached a summary plot from the our system which does hit at what I am talking about... Compare the May / June period from 2020 and 2021. Just peeking at the graph it looks like the ERV maintains a much higher humidity (but still in the good range) than the HRV core with supply values ~ 10g/Kg for the ERV core versus 6-7g/Kg for the HRV core. In the most comparable time last year we were not at home 100% of the time like we have been this year. So maybe a humidifier is on the cards?



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