Air conditioning unit what to expect.

[ericmark]

Last year I got a Comfee air conditioning unit from Lidi rated at 7000 Btu 3.3 amp 755 watt, which does not seem right as 7000 Btu is just over 2kWh but it is using 698 watt on my energy meter.

Thinking I was buying a 2kW unit I was rather disappointed with performance, but at 700 watt suppose not that bad, however I have only used window mount air conditioners in the past, the type which fit on a tray behind a oblong hole in the wall, and they were 2 kW.

So what I want to know, is my unit doing as should be expected for such a small unit, or not, in the past they were fitted to porta cabins not in a house, and it was a tad warmer outside in Algeria and Hong Kong.

So clearly sucking air from the room to cool the heat exchanger means warm air from outside is sucked in to replace it, the exhaust goes up the flue, then we can keep windows closed, it is a large room with loads of windows so does get hot, which is why we bought it, and if turned on early it will maintain the room temperature, but we tend to get hot, then decide to use it, and it is very slow cooling down the already hot room.

So how do I work out, is the AC OK but too small for the room, is the problem due to venting up the flue, or is it faulty?

 

[bernardgreen]

Assuming this is a heat pump type air condition then the 2kW rating is the amout of heat being pumped out of the room and 755 watts is the amount of electrical power needed to pump the heat.

Heat pumps typically have a CP of between 3 and 4, Yours has a CP of about 3.6 which is OK for a small unit.

Total heat dumped = 2000 + 755 watts 2755 / 755 = 3.6

CP - Coefficient of Performance