Completely normal,
It is currently -8 Celsius outdoors where I live, and I have not had my heat turned on this winter, the 20+ 1070 ti SC Hybrids scattered over three rigs, completely heat a 1000 square foot 2 story , 2 bedroom home to 23+ Celsius, which is a more than comfortable temperature to wear a t shirt indoors in the winter, now when summer comes I will need to have many windows open, but in the winter the only downside is that the Air gets extremely dry, and static electric becomes more of a concern so thus needs to be mitigated,
wow thats crazy, so in cold climates it really benefits to have rigs. I havent put the heat on either and I its cold out so I know its suppose to be on I thought I was bugging. this will be a pro for the winter time! Become a miner and heat your home at the same time lol