Not at all. First, (hot) water batteries are excellent for home heat storage. Sand/dirt is even more storage per volume required, and completely complimentary in sending hot water through it (pipes) to make it hotter. No combustion heat means less air exchanges, and a 300C rock/dirt/sand pit has losses that radiate through house.
Not at all. First, (hot) water batteries are excellent for home heat storage. Sand/dirt is even more storage per volume required, and completely complimentary in sending hot water through it (pipes) to make it hotter. No combustion heat means less air exchanges, and a 300C rock/dirt/sand pit has losses that radiate through house.