Portable Room Air Conditioner

[wayned]

Does anybody have one of these "swamp cookers".  I'm looking at a 12000 BTU unit,http://www.lazada.co.th/natural-natural-12000btu-nap-4122-6033822.html, and my concern is that although it cools it vents the exchanged air  directly from the unit into the same space that it is cooling.  The one I'm looking at comes with an external  removable vent adapter, but that defeats the "portability" option.

 

I really don't like air con but I am getting older and a cool breeze would be great sometimes.

 

Any thoughts or recommendations would be appreciated.and

[Artisi]

First up, looking at it without any real tech data, I would say it's not an air-conditioner in the sense that people understand, it doesn't run a refrigeration system with a compressor etc,  it appears to be what the Americans call a "swamp cooler"  or evaporative cooler -  meaning it blows air across a wet surface utilizing physics to cool the air -- they are only really effective with very low humidity - unfortunately something Thailand doesn't have.

 

I have one  and sometimes use it in the bedroom during summer in lieu of the ceiling fan, and to be honest I find it to only be marginally  better that the c/fan.

 

I suggest you research "swamp coolers and evaporative coolers on the net , there is a wealth of data there including tables showing the temperature drop you can expect based on ambient temperature and relative humidity - look at what you can expect from it using your local weather data.

[wayned]

Actually the unit above is an air conditioner with a compressor.  The manufacturer recommends that it be vented outside using the kit that is supplied with the unit.  I just wondered if anybody has one that they tried without the outside vent an pretty much know the answer that to be efficient it must be properly vented.  I know all about "swamp coolers" as I have used them in the deserts of New Mexico and California and have looked at the charts many times.  I'll probably buy one just to try it.  The temp is now 84F and 60 % humidity so the unit should be capable of lowering the temp to 76F.  In the afternoon when the temp rises to 100F the humidity drops to about 40% and the unit should be capable of producing 85F.  All theoretical from the charts , but the swamp coolers aren't that much more expensive than a good fan and IMHO ceiling fans don't hack it unless you are directly below them ( I have 10 installed in my house).

 

Thanks for your input!

[r136dg]

I have something like that. Unfortunately it's  been buried in storage for some time & I can't get a look at it, but I'll tell ya what I recall about it. If it would help I'll dig it out.

 I don't think the temp setting went down to much, maybe 28-30c. In a hot room it would blow out nice cold air stronger than any AC unit I have; however, the exhaust was also blowing out warm air. I'd strongly recommend exhausting out a window, or something, to be effective. In my case it was used out in my car port area where I'd be doing a lot of wrenching. Very effective for the area I was working and the exhaust was simply laid down in the opposite direction. 

I may use it again when our new home is completed for the garage. If so, it will definitely exhaust outside.

By the way, mine did come with an adjustable plastic plate for blocking the section of window open that lets exhaust out.

[Artisi]

6 hours ago, wayned said:

Actually the unit above is an air conditioner with a compressor.  The manufacturer recommends that it be vented outside using the kit that is supplied with the unit.  I just wondered if anybody has one that they tried without the outside vent an pretty much know the answer that to be efficient it must be properly vented.  I know all about "swamp coolers" as I have used them in the deserts of New Mexico and California and have looked at the charts many times.  I'll probably buy one just to try it.  The temp is now 84F and 60 % humidity so the unit should be capable of lowering the temp to 76F.  In the afternoon when the temp rises to 100F the humidity drops to about 40% and the unit should be capable of producing 85F.  All theoretical from the charts , but the swamp coolers aren't that much more expensive than a good fan and IMHO ceiling fans don't hack it unless you are directly below them ( I have 10 installed in my house).

 

Thanks for your input!

The evap. coolers must be the current rage as they are in every store at the moment. 

Must pull mine out and give it another run - as said, I didn't find it that more effective than the ceiling fan - but then the bedroom fans are directly over the beds. 

[ricklev]

http://www.consumerreports.org/cro/news/2014/06/are-portableair-conditioner-claims-a-lot-of-hot-air/index.htm

[sfokevin]

One not mentioned problem with these portable units is that if you properly vent them to the outside the unit creates a vacuum in the room... Hot air from the unit is expelled but that air must be replaced... most likely from under the door or cracks in window fitting... Basically sucking more hot air from outside into the room... 

[r136dg]

1 hour ago, sfokevin said:

One not mentioned problem with these portable units is that if you properly vent them to the outside the unit creates a vacuum in the room... Hot air from the unit is expelled but that air must be replaced... most likely from under the door or cracks in window fitting... Basically sucking more hot air from outside into the room... 

Good point! 

As said, mine worked great in a car port that wasn't entirely enclosed. Lot of wasted energy for that comfort though.

[cooked]

We don't seem to have worked out that swamp coolers and portable air conditioners don't work in the same way. A swamp cooler does give you cool air but the air is cool because of its moisture content, and in Thailand the last thing you want is more moisture. They work better in hot dry countries like Arizona for instance than here. However if you want to sit outside they will keep you cool and drive away the mozzies.

I had a portable air conditioner at one time which I was able to use in my office which was the only place I could vent the hot air out of. It worked. but it was relatively expensive compared to a wall mounted one so I wouldn't buy another.

[wayned]

I imagine the portable air con units without venting would be just like mounting a small widow unit on a frame in the middle of the room.  Cold air blowing out the front, hot air out the back and water dripping on the floor.  Put a fancy case on it. a venting kit, a drain kit,  and some wheels and you have a portable unit!

[stubuzz]

I had an AJ 12000BTU potable air con unit.  It was useless and noisy and would not cool a 12m2 room.  Do not waste your money.

P.S-it also used more electricity than a fixed unit.

[wayned]

After reading the thread, I decided to buy a "evaporative cooler" and find out for myself.  I bought a Mitsuta MEC95, one of their larger units.  According to specs it is designed for a room 30-50M2, moves 2400M3/hour, weight (empty) 11.5kg. and uses 130  watts.  It has a 32 liter water holding tank.

 

I filled it up and tried it in my living room, open windows, no air con.  The temperature was 35.5 degrees with 37% humidity.  I taped the gauge to the front of the unit and the air coming out was 28.3 degrees and the humidity was 77%.  It was a nice cool breeze and I enjoyed it for the afternoon.  It used about 12  liters of water in 3 hours.

 

I took it in the bedroom and put it on a table in front of a window that was closed to the width of the unit so that it would draw air in from the outside.  I closed the other windows and the bathroom and walk-in closet doors so the area to cool was 16M2, about 352M3  I refilled it before I put it on the table -MISTAKE- as that added 32kg to the weight and it was a trick to lift it without spilling the water.  When I turned it on at 1630, the temp in the room was 35 degrees.  At 0200 I turned it off and the temp in the room was a comfortable 28 degrees so I guess that it did something.

 

One thing that worries me is using "tap" water as the water supply here is very hard.  I  might switch  and fill it with drinking water. I use rain water run off and have 12 ongs of it  outside with a separate pump and faucet in the kitchen.  It will take some modification to hook a hose to the faucet that I can remove after use, but I'm good at being Rube Goldberg.

 

Just an update.

 

 

[Don Mega]

A quick look on google suggests the average overnight low for Nakhon Sawan at the moment is 25 degrees, be better to crack a window and use a fan than that cooler thing.

[wayned]

There you go believing Google again!  I've lived here, in this house, for 18 years and this time of the year I've never seen it that low. It's now 0510and  I just looked at the gauge outside and it's 29 degrees and all windows in the house are open - other than last night - and the current temp on my desk thermometer is 29.5 with a humility of 61% with a ceiling fan  and an 18" floor fan going full bore.  The nice thing I found about the cooler is that it blows acceptable cool air at 1900 when I retire to pretend to watch TV so I guess that I will try it for a little longer.  If the outside air was actually 25 degrees all of the time I wouldn't have started the thread but when it heats up to almost 40 degrees during the day it takes a long time to cool off to the "average overnight low" and I'm interested in achieving a reasonable temperature before the lower outside temperate has reached that mark without installing air conditioners..

[Don Mega]

Enjoy your humidity maker then.

[CGW]

Would a small air con not be more efficient and comfortable, seems to me it would?

[Ace of Pop]

I always thought nothing from nothings does nothing.like a cooler.I was wrong it appears.[emoji84]


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[Crossy]

1 hour ago, Ace of Pop said:

I always thought nothing from nothings does nothing.like a cooler.I was wrong it appears.

 

But the water is evaporating and absorbing heat from the air. About 2.258 MJ per litre of water evaporated.

 

If it's using 4L of water per hour, I work that out to be about 8,000 BTU of cooling which is pretty good (maybe someone could do the sums too). Of course that assumes all the water used is being vaporised. And you now have 4 L of water causing humidity.

 

[Ace of Pop]

Sums iz Luvly, but over the years ive seen dozens of em.. So have my Chums here and cant see what they do really apart from use electric.So the consensus s of 6 "Old Grumpies" round this table,is that they are Crap.We are all agreed on that. A rare occasion indeed..

[wayned]

15 hours ago, Ace of Pop said:

Sums iz Luvly, but over the years ive seen dozens of em.. So have my Chums here and cant see what they do really apart from use electric.So the consensus s of 6 "Old Grumpies" round this table,is that they are Crap.We are all agreed on that. A rare occasion indeed..

Six CCGOFs sitting around a table and agreeing on anything is definitely a rare occasion unless the beer is cold and has been running freely for some time.

 

 I disagree that they are "Crap"!  If they were crap when you turned the on the air would have a distinctive smell.   They  work as they were designed to work but don't work well in climates with high humidity..  I bought one mainly just to see.  As far as cooling a room like an air conditioner, there's no hope.  Mainly due to the fact that they only work in low humidity environments but also by the design of the units that they sell here.  Unlike an air conditioner which recycles the air in the room and cools it in the process, the coolers must "replace" the air in the room bringing in outside air, cooling it by the evaporative process,  and replacing the air in the room.  Their inputs should be placed against and open window so that they draw air from the outside and prevent them from drawing in the room air.  The design of the units that I've seen here, including the one that I bought, have intakes on the back and both sides preventing this so the design is flawed.

 

Having said that,  I have found that they do have a useful function.  When you use just a fan and it's 35.5 degrees in the house you get blasted in the face with 35.5 degree air.  With the cooler that I bought, The room was 35.5 degrees and the temperature of the air out the front was 28.3 degrees, so you at least get a cool breeze which makes it more comfortable.and only uses 130 watts to do it.

 

 

[Crossy]

I'm actually tempted for our downstairs entertaining area, open on all sides fans are pretty good but a bit of chilling never hurt

 

Owmuchwazzit?

 

[wayned]

I looked at them in Tesco and finally decided on this one from Lazada http://www.lazada.co.th/mitsuta-30-50-mec95-gray-229246.html

 

It's actually supplied directly from Mitsuta Electric in Bangkok.  I chose it because of the size of the water tank, 32 liters.  It has good airflow, a timer and a cutoff when the tank goes dry.  I only have had it since Tuesday but have experimented with it over the past 4 days and so far I am happy with the unit.

 

It cost 4980 baht and thought that it was a better deal than a comparable priced Hitari unit that had in Tesco that only had a 20 liter tank. Mitsuta also have larger units but more than I wanted.  Last night I set the timer for 6 hours and it used about 16 liters of water.