Considering winter is right around the corner, I would place these units strategically in corners of each room. Turn them on when it gets chilly. You can probably set them on a timer too so that your house is nice and cosy when you get back from work.
Also, if you have a newborn at home, they make a very enjoyable background sound that will soothe him/her to sleep.
Good advise, really. Winter is coming, so have a free warming in your house, also who knows what will happen this winter? Maybe prices of Scrypt coins will rise and you'll profit too? Well OP, I suggest to wait and sell after winter, there are a lot of good advices/techniques how to turn antminers into good house heater and profit at the same time.