Photo from www.alpha-heater.net |
With people working from home more, worrying about keeping warm and high energy costs, there has been a lot of publicity about 'miracle' mini electric heaters. I saw an ad on YouTube the other day promoting an amazing invention called the Alpha heater. It claimed that it was the result of years of research from a former jet engine engineer, and would slash your fuel bills. Being a skeptical Engineer I thought I would do a little research on this miracle product. The bottom line is that:
It is a cheap (six dollar) plugtop PTC heater made in the Far East, but sold at high prices under various brand names such as Alpha Heat.
These heaters have claimed power ratings in the range 300 to 500W. All (resistance) electric heaters are essentially 100% efficient, so a heater that uses 500W of electricity will only generate 500W of heat. As a comparison, a traditional convector or fan heater will generate 1000W on the low setting.
Some simple maths will confirm whether it 'costs pennies to run'. A 500W heater uses 0.5 kWh (kilo Watt hours) of electricity in an hour. So based on current UK capped price of 34p/kWh this means the heater will cost around 17p/hour to run.
The advertisers make fanciful claims, i.e. it takes only seconds to heat up a large room; it somehow recycles the heat; it saves 80% off your fuel bill; it filters the air. All of these claims are false.
The internet is rife with false advertising for these heaters, therefore it is quite difficult to find genuine reviews. There are some review videos on YouTube, but these tend to be comparing the Alpha heater with other brands, which they are then promoting. One of the more useful ones is from "Krazy Ken".
So are some electric heaters more efficient than others? The answer is yes and no. As previously stated, all resistance heaters will be around 100% efficient. However, how you feel the heat can be affected by whether the heat is convected or radiant heat. With convection heaters (which confusingly includes traditional domestic "radiators"), the heat rises, so a lot of the heat ends up in the top third of the room. On the other hand, infrared heaters produce mostly radiant heat. If you are in the path of this radiant heat it will make you feel warmer. Therefore infrared heaters can give acceptable comfort levels operating on less power.
Heat pumps are typically 300 to 400% efficient, but there is no magic or miracles involved. Although heat pumps are powered by electricity, the heat is actually being extracted from under the ground (ground source heat pump) or from the outside air (air source heat pump).
In conclusion, as with a lot of these scam products, if it sounds too good to be true then it probably isn't true!
Disclaimer: This is my personal blog. Views expressed in my posts are my own and not of my employer. The information provided comes with no warranty. I cannot be held responsible for the content of external websites. Any practical work you undertake is done at your own risk. Please make health and safety your number one priority.
As a fellow engineer, I get irritated when I see claims that a resistance type heater will slash energy bills compared to other heating types. As you’ve pointed out, a heat pump is much more energy efficient than a restance type heater (300-400% vs 100%). My guess is that numerous consumers who have a heat pump for heat are getting “ripped off” and tricked into buying these resistance type heaters. Long story short, thanks for posting this info… hopefully it keep a few heat pump owners from getting duped.
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