I have been hired to write a book about the heating & cooling industry, & I certainly do not know why I was hired or anything about heating & cooling! Out of all the things I have been hired to write books about, this is the first time I am totally clueless! If the spend money was not so good, I would have turned down the task & done something else. But for the pay, I could not say no! So, I have to do a whole ton of research on the odd kinds of heating & cooling related technology & component available! So far, in our research, I have seen things & l received about radiant radiant floors, smart temperature control control units, ductless mini-split heating & cooling systems plus things about the aged heating & cooling component love window air conditioning system units, which were what most homes had before central heating & cooling became available to pretty much everyone at an affordable price. I also have been reading about space heaters, in which space gas gas furnaces are a cheap way to heat your home plus save a whole ton of currency on your yearly & weekly electric bills. Actually to be honest with you, after doing all this research & learning all about the ins & outs of the heating & cooling technology plus the up-to-date heating & cooling systems, I almost want to become a certified heating & cooling worker! But, I certainly make a few more bucks writing the books, so I know I will stick with that for now.