DIY air conditoner

[Leros]

Its getting hot here and my dorm has little to no air conditioning.

I was looking as some ideas online, such as this

http://www.eng.uwaterloo.ca/%7Egmilburn/ac/pete_ac.html

Anyone ever tried anything like that? Looks like it will work, I'm just not sure how long the ice would last for.

 

[Heisenberg]

Why not just get a window unit?

 

[Leros]

Originally posted by: Heisenberg
Why not just get a window unit?

We aren't allowed to. Technically its against the rules to open the window at all. We've been able to crack it open a bit without attracting any attention, but a window unit surely would get us in trouble.

 

[Jeff7]

Where will you get the ice from?

 

[MercenaryForHire]

Ah, Waterloo Engineering students. Always ready to build something needlessly complicated at a moment's notice, rather than using an existing solution. Also, they never get laid.

/ex-Mathie

- M4H

 

[fLum0x]

what the hell? Put fans in front of the windows and crack them some...that will get air flow. We were allowed to open our windows...but we had 4 box fans running at all times :x

2 sitting on the window edge and 2 on top of those

 

[BrokenVisage]

Originally posted by: Leros

Originally posted by: Heisenberg
Why not just get a window unit?

We aren't allowed to. Technically its against the rules to open the window at all. We've been able to crack it open a bit without attracting any attention, but a window unit surely would get us in trouble.

WTF? You pay to live there, you should be able to open any damn window you want.

 

[ElFenix]

Originally posted by: Heisenberg
Why not just get a window unit?

probably can't put one in a dorm window.

my dorm the windows were bolted shut (which didn't stop us from opening it, of course).

 

[Leros]

Originally posted by: BrokenVisage

Originally posted by: Leros

Originally posted by: Heisenberg
Why not just get a window unit?

We aren't allowed to. Technically its against the rules to open the window at all. We've been able to crack it open a bit without attracting any attention, but a window unit surely would get us in trouble.

WTF? You pay to live there, you should be able to open any damn window you want.

Its a $50 fine for every time they catch us with the window open. The idea is that when it gets to be 100 degrees outside, they would rather we keep the windows closed.

 

[Al Neri]

why cant you open your window?

 

[Leros]

Originally posted by: MercenaryForHire
Ah, Waterloo Engineering students. Always ready to build something needlessly complicated at a moment's notice, rather than using an existing solution. Also, they never get laid.

/ex-Mathie

- M4H

What would you suggest?

 

[Leros]

Originally posted by: Don Rodriguez
why cant you open your window?

Its against university policy and we'll get fined for it. They say its because the dorm's AC runs better when the windows because opening the window only lets cold air out and hot air in.

Thats all fine and dandy, except the A/C in my dorm sucks. The air coming out is about 75-80 degrees and when you add the fact that both my roommate and I have desktop computers, the heat builds up really fast and becomes unbearable.

Plus there is a parking lot outside my window so the air is slightly warmer than the rest of the air outside.

 

[Jeff7]

But where's the ice coming from?

If you're making it in a refrigerator in your room, well, you'll only heat up the room.


If you're transporting it in, you'll need a lot of ice to get a significant change in temperature. The copper tubing in the link is just a way of getting the lack of thermal energy in the ice into the room faster. The net result though is the same as just setting the ice in the middle of the room, and waiting for it to melt. Either way, it'll absorb thermal energy from the air, and thus cool the room. Slightly.


That's kind of stupid to not be able to open the windows though.

Thats all fine and dandy, except the A/C in my dorm sucks. The air coming out is about 75-80 degrees and when you add the fact that both my roommate and I have desktop computers, the heat builds up really fast and becomes unbearable.

Do what I'd do - violate University policy again and disassemble the unit to try to find out why it sucks. I already made this University apartment's bathroom fan quieter by installing silicone rubber grommets between the motor and the mount. This has the side effect of prolonging the lifespan of the cheap, poorly made, unbalanced plastic blowers that tend to crack and make horrendous amounts of noise after 1-2 months. The one that's in there has been working since sometime last semester, and that's after I epoxied it up after a crack formed. It's still loud, but it's not technically broken, so maintenance won't replace it. They won't replace a blower that probably costs them $1.

 

[fuzzybabybunny]

Originally posted by: BrokenVisage

Originally posted by: Leros

Originally posted by: Heisenberg
Why not just get a window unit?

We aren't allowed to. Technically its against the rules to open the window at all. We've been able to crack it open a bit without attracting any attention, but a window unit surely would get us in trouble.

WTF? You pay to live there, you should be able to open any damn window you want.

My university dorm used to be the same way.

1. Afraid student-installed units could be improperly installed and fall on people underneath.
2. Fire hazard; window units have not been inspected to pass school standards.

When I lived in the dorms, I did it anyway. It was 80-90 degrees and not having air conditioning was just unacceptable to me. I was on the ground floor and my air conditioner just sat on the sill with no part sticking outside. The screen was even still installed. As for the fire hazard? Whatever.

I was told to take it out twice, but never did. Luckily it was just for the summer.

 

[Leros]

Originally posted by: Jeff7
But where's the ice coming from?

If you're making it in a refrigerator in your room, well, you'll only heat up the room.


If you're transporting it in, you'll need a lot of ice to get a significant change in temperature. The copper tubing in the link is just a way of getting the lack of thermal energy in the ice into the room faster. The net result though is the same as just setting the ice in the middle of the room, and waiting for it to melt. Either way, it'll absorb thermal energy from the air, and thus cool the room. Slightly.


That's kind of stupid to not be able to open the windows though.

There is a 7-11 a few blocks down the street. I was thinking if a $2 bag of ice could last me for a few days, then it would be worth the money.

I'm not sure how long a bag of ice would last, hence my post here.

 

[jfall]

Buy a portable air conditioner

 

[Leros]

Originally posted by: jfall
Buy a portable air conditioner

And where does the heat go?

 

[Rubycon]

Originally posted by: Leros

There is a 7-11 a few blocks down the street. I was thinking if a $2 bag of ice could last me for a few days, then it would be worth the money.

If you could use the coolth in a 20 pound sack of ice with 100% efficiency you would only yield the equivalent of 120 British Thermal Units per hour. A TINY window shaker is 5000 BTU/h.

Just stick with the fan and sweat. The evaporative cooling on your body is more efficient.

The ideal way to remove heat from an inside room, room with window that cannot be opened, prison cell, etc. is a Koldwave unit. It's basically an air conditioner with a water cooled condenser. You can use tap water if you like.

EDIT: 120 btu/h would be a 24 hour rate. To make the ice last two days it would be 60 btu/h. Your PC puts out more heat than that!

 

[Jeff7]

Originally posted by: Leros
There is a 7-11 a few blocks down the street. I was thinking if a $2 bag of ice could last me for a few days, then it would be worth the money.

I'm not sure how long a bag of ice would last, hence my post here.

I'd wager, not very long. It might last that long if it is left in a cooler.


I don't think the calculations are too bad either, probably just algebra, to figure out exacty how much of a temperature reduction you could get out of a bag of ice, but it's not very much I'd bet. I think it would have to take into account the mass or volume of the ice and the air, as well as their heat capacities.

Still, a $2 bag of ice is, let's say, 0F. That's 70 degrees colder than you want it, and it's a small volume. The air is a big volume, let's say 15-20 degrees warmer than you want it. I don't think that the small bag of ice will make much of a difference in the room's temperature, and I don't see it lasting more than several hours, unless it's in a cooler, in which case, you're simply reducing the rate at which the thermal transfer occurs.


Re: Ms Dawn's response:
There you have it. Go get yourself 833 pounds of ice, and enjoy a cool, wet afternoon.


Your other option: lasers. Precisely timed laser pulses can cool atoms down to close to absolute zero. For several hundred million dollars, you can turn the air in your room into a frosty Bose-Einstein Condensate.

 

[jfall]

You'd still have to vent it out the window, but it's only a small vent as opposed to putting a whole unit in the window which would get noticed much easier

 

[Leros]

Originally posted by: MS Dawn

Originally posted by: Leros

There is a 7-11 a few blocks down the street. I was thinking if a $2 bag of ice could last me for a few days, then it would be worth the money.

If you could use the coolth in a 20 pound sack of ice with 100% efficiency you would only yield the equivalent of 120 British Thermal Units per hour. A TINY window shaker is 5000 BTU/h.

Just stick with the fan and sweat. The evaporative cooling on your body is more efficient.

The ideal way to remove heat from an inside room, room with window that cannot be opened, prison cell, etc. is a Koldwave unit. It's basically an air conditioner with a water cooled condenser. You can use tap water if you like.

EDIT: 120 btu/h would be a 24 hour rate. To make the ice last two days it would be 60 btu/h. Your PC puts out more heat than that!

So you're suggesting that killing my roommate and turning off his computer would be more effective.

 

[rmrfhomeoops]

Originally posted by: Leros

Originally posted by: Don Rodriguez
why cant you open your window?

Its against university policy and we'll get fined for it. They say its because the dorm's AC runs better when the windows because opening the window only lets cold air out and hot air in.

Thats all fine and dandy, except the A/C in my dorm sucks. The air coming out is about 75-80 degrees and when you add the fact that both my roommate and I have desktop computers, the heat builds up really fast and becomes unbearable.

Plus there is a parking lot outside my window so the air is slightly warmer than the rest of the air outside.

Complaint to you RA in person or at the next meeting. If that doesn't get resolve soon, talk to the manager in the housing office. It's more effective too if you have your parents call the manager. Have your neighbors sign up a petition too have a working AC unit; you write the petition and they sign it.
Talk to people in charge/responsible is more effective than try to haul an ice box to your room everyday.

 

[Rubycon]

Originally posted by: jfall
You'd still have to vent it out the window, but it's only a small vent as opposed to putting a whole unit in the window which would get noticed much easier

Ice is thermal storage. Thus no venting required unless you factor in removing the water.

Originally posted by: Leros


So you're suggesting that killing my roommate and turning off his computer would be more effective.

I'm sure this can be settled in a much more diplomatic method without resorting to violent practice. Just don't let the heat drive you insane.

 

[rmrfhomeoops]

Originally posted by: jfall
Buy a portable air conditioner

Good idea, but spendy though; start at least $300 for 8000 BTU unit. Also not sure how much space OP have in his room.

 

[Tiamat]

Ice-water baths usually stay cold for a while. In a 10 gallon aquarium, I have kept a 4 Celcius water bath using 2 bags of ice over the course of 1 hr. At the end of the 10 hrs, it had increased to 6 Celcius in an ambient of 19 Celcius. (Of course your ambient is probably closer to 35C)

Instead of using copper coil, an old Car radiator would work better with a high power fan due to the increased air flow and vastly increased Surface area. Unfortunately, i doubt you will get much satisfaction after this amount of work. Just get a high flow fan and point it at you.