I use the DHT22 for both temperature and RH.
I'll place them like this inside the HRV chassis:
- Income fresh air (in the outside hood)
- Fresh air right after heat exchanger for calculating the COP
- Fresh air after post heater for reading the amount of heated air
- Return stale air
- Bathrooms return stale air (only RH reading) for triggering forced refreshing
Apart these I'll have another DHT22 placed over the oven in the kitchen for the same reason as the bathroom, as well as a relay on the motor of the kitchen hood.
I am currently finishing the dumpers using small Emax servos.
Just got an eye on Blynk, seems cool! Do you have any experience with that?