In twin function systems (each heating and cooling), the warm season gives ground thermal recharge for the cool season and the cool season gives ground thermal recharge for the heat season, greenhouse small though overtaxing the thermal reservoir have to be thought-about even with twin function systems. There have been even experiences of homeowners blatantly "flipping" barely used GTs in pursuit of a fat, fast revenue. In 2019, data states that there was 409.8 parts per million of carbon diox...