Looking for a good/energy efficient portable A/C [Archive]

radford

07-24-2009, 04:52 PM

Hi, does anyone know any good portable a/c for a room?
And does anybody know if it makes a big difference on electric bill?
Thanks in advance

Most or maybe all portables arent that efficient, in fact they are terrible compared to window units. Even the so-called bad window units that dont have decent EER ratings look good vs a portable.

Since portables arent that efficient , the usual comment is --- it cools way less than a weaker window unit. In fact I used to see this posted all the time and now that portable units are much more popular and cheaper --- they often come with warnings. For instance around here I used to only see 600-800 buck portables but the last 2 years started seeing 299-399 portables at Wal Mart and SamsClub. The (correction) GE unit comes with a warning that it may not cool properly in extreme situations --- something Ive never seen before on a air con.

So in general I used to see really high BTUs on portables 10,000+ I presume because they are much less efficient which makes them equivalent to a weaker window unit. Usually I used to see around a very general 1/10 relationship between btu and watts. So 10K btus would equal around 1000 watts. That depended on the efficiency of the unit of course so it might be more or less. The really efficient ones may use say 850-920 watts or so. Ive never seen any articles about whether turning the fan/cooling down significantly affects the watts usage.

Though you can find 399 units online with 10,000 btu generally Ive seen the 299 and 399 units at wal mart with 7000-8000 btu. Given that they are less efficient than window units you might guess that they are equal to a 4000-5000 btu window unit. Even then it might vary. Maybe portables are even worse in various situations like high humidity conditions -- I dont know. One thing I noticed obviously when humidity gets really high the air con has to work much harder so it seems far less effective and in fact the Panasonic 10,000 btu which works fantastically can seem almost ineffective at rare times when the humidty got sky high around here.

So I wonder if portables suffer even more since there are always mixed reviews for portables. Some people say it works great while others with the same model say it doesnt work at all. One factor besides temp and humidity is whether its a one pipe or two pipe. Generally speaking --- many people claim the two pipe units which are more expensive , work a lot better. Two pipes mean theres one for the intake of cool air from the window and one for the expulsion of hot air to the window. Most are one pipe --- exhaust only , they get their intake air from the room I think. Another thing is reliablity , its generally rated much lower on portables. And then theres the water tank. Some claim to evaporate the water that drips from the coils and exhaust it out the pipe I think while others , you have to empty it out all the time. Some have autoshutoffs when it gets full while others I think overflow.

And sure --- if you use 1000 watts for a large part of the day every day, it can add up a lot in high cost areas. It can add 25% or more to your electric bill. Obviously it all depends on your specific rates in your region and how much you use it.

If you want to get really accurate rates get one of those KILL A WATT devices that measure actual usage and experiment with the air con at different settings and then look up your power rates in your region and calculate it with your projected usage. I assume the Kill A WATT can handle an air con but Im not sure about that.