Cool as a cucumber
July 18, 2011 4:14 PM   Subscribe

Hypothetical thermo-engineering question. Let's say you have a room. It's a living room. It's about 300 sq feet and open on one end (This can't be closed). There's an air conditioner in the living room in the window on the west side of the room. The problem with the air conditioner is that it doesn't project very well. There's a few feet of empty space between the air conditioner and the couch, which it does a great job of cooling, but if you're not standing in front of it you're SOL.

I had this idea: I took the box the air conditioner came in yesterday (this box had a removable bottom) and fit it over the air conditioner to form a tunnel for the air to go through. I thought maybe that would prevent the cool air from dissipating immediately and help it go a little further and also help it stop leaking through the sides of the window (which are plugged up pretty good, but still, trying to salvage every last drop of cold air here). It doesn't seem to be working that well though.

Why or why not?
posted by bleep to Technology (9 answers total)
 
Where's the return air vent?
posted by roboton666 at 4:17 PM on July 18, 2011


Best answer: You need to circulate the air in the room more than you need to direct it with a box-tunnel attachment-contraption. Put an oscillating fan at the other end of the couch facing away from the air conditioner, you'll draw the cold air across the couch and circulate warmer air back towards the a/c for it to cool off.
posted by carsonb at 4:17 PM on July 18, 2011 [3 favorites]


What is the cooling capacity of your AC in BTUs? For a 300 sq ft closed room you'll need at least 8000 BTUs. For an open ended room you would likely need more.
posted by markulus at 4:24 PM on July 18, 2011


Response by poster: The AC is 8,000. This was the upper level of what I could afford.
I did actually try closing off the open end, but it didn't make much difference for how ugly and inconvenient it was.
posted by bleep at 4:27 PM on July 18, 2011


Best answer: I agree with carsonb that air circulation is the key.

But there is a fan which is claimed to be able to essentially shoot a beam of air for some distance (70 ft.) through the ambient air of a room instead of dissipating its effects within a few feet of the blades as an ordinary fan does.

It's called a Vornado, and the 'beam' of air is a vortex.

If I were you, I'd get the 630 model and put it on the floor where the heavy, cold air from the air conditioner falls down and beam that cold air wherever I wanted it to go in the room.
posted by jamjam at 5:01 PM on July 18, 2011 [1 favorite]


The problem is not how you circulate the cold air, nor that it isn't being directed well. The problem is there isn't enough of it.

I can blow through a soda straw across a block of dry ice. The tiny jet of wind will be really cold... if you're right next to the block. But I won't be moving much thermal energy (producing much thermal power), in the bigger sense.

Neither is your lousy AC. If it worked well, it would make a significant portion of the room very cold (if there wasn't good circulation), or else the entire room would cool significantly (if there is good circulation). Since the cooling effect is only felt near the AC, it isn't doing much.

You're wasting time trying to find the magical, nonexistent circulation pattern. Get a better AC (freecycle, cheapcycle, Craigslist...).
posted by IAmBroom at 6:59 PM on July 18, 2011


I've had a similar issue -- AC in the dining room, wouldn't flow well into the living room. What has taken me 10 years to realize is that if I open the window (on the opposite side of the living room from the dining room) just 1/2 an inch, my whole living room magically becomes air conditioned.

Also, opening a window on the far side of the top floor, again just a teeny bit, will also help.


Y'know, if your house is shaped the same as mine . . .
posted by MeiraV at 7:32 PM on July 18, 2011


Yeah, you're just way undersized for that room. (What is the ambient outdoor temp?) What you could do is duct tape some flexible duct (at least 4" diameter, a bit bigger is better still) to the outlet, and stick the other end near your face. :)
posted by trevyn at 4:56 AM on July 19, 2011


Response by poster: The fan in front of the AC wound up helping a lot. One of those regular old big box fans. Thanks!
posted by bleep at 4:02 PM on August 19, 2011


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