Warm air heater

Chat with fellow forum users. No adverts or trade links in here please.
Post Reply
Alys
Posts: 29
Joined: Sat Feb 03, 2018 1:08 pm

Warm air heater

Post by Alys »

I'm thinking of getting a standalone electric warm air heater for the winter. I notice that the high tech Dyson one costs around 700 Euro. I was looking for something cheaper. Does anybody have any suggestions please? Thanks.
Anarita John
Posts: 902
Joined: Thu Dec 29, 2016 8:18 pm
Location: Formally Rochdale, Penrhyn Bay and Anarita

Re: Warm air heater

Post by Anarita John »

Even the older air con units, set to heat, are much cheaper to run than any form of electric heating. On the older units, for every kw you burn, you get around 3kw of heat, whereas the newer units are even more efficient. We have two new, LG units, which we have used for aircon all summer, and intend to use for our heating in the winter. They were fitted by one of the site sponsors and we have been really pleased with them. Unlike the older units which we used to have, they are silent.
DavidatLWH
Posts: 492
Joined: Sat Mar 25, 2017 10:41 am

Re: Warm air heater

Post by DavidatLWH »

Anarita John wrote: Sat Oct 31, 2020 11:45 pm for every kw you burn, you get around 3kw of heat, whereas the newer units are even more efficient.
I think the first Law of Thermodynamics might be a problem with that.
Anarita John
Posts: 902
Joined: Thu Dec 29, 2016 8:18 pm
Location: Formally Rochdale, Penrhyn Bay and Anarita

Re: Warm air heater

Post by Anarita John »

1kw of electric can produce 3kw of heat with an air con unit. No other form of heating can do this. 1kw burned produces 1 kw of heat. I am sure Max or Devil will contribute to explain the science. In fact it was a post many years ago on the Eastern forum by Devil which got us using aircon for heating. Previously we had used our oil, underfloor heating, which we found very expensive.
User avatar
Devil
Forum Curmudgeon
Posts: 3939
Joined: Wed Dec 28, 2016 8:34 am
Location: Mosfiloti

Re: Warm air heater

Post by Devil »

Perfectly true! With any form of electric heater, you convert the electrical energy directly into thermal energy with an efficiency of 100%. With a heat pump, you extract energy from an outside source at a low temperature and convert it to a higher, more useful, temperature. Example: blow up a bicycle tyre with a hand pump. The pump will get quite hot because you are using energy to compress the air but the energy you are using is mechanical from your hand. At the same time, the air in the pump cylinder gets hot while a vast amount of air surrounding where you are pumping gets cooler. In practice, the amount of heat apparently produced by compressing the air is heat which is extracted from the region round where you are pumping. It is not the energy of the actual pumping. Under the right conditions, a heat pump will give the user three or four times as much heat as the apparent energy required to operate the pump.
Alys
Posts: 29
Joined: Sat Feb 03, 2018 1:08 pm

Re: Warm air heater

Post by Alys »

Thanks to everyone for your quick replies. Mouse, the answer is yes. I live in a 30 year old concrete block!
Post Reply