DIY Solar Air Conditioner

ozarkcabin

Hi,

Since running an air conditioner is one the biggest hits on power consumption, and in turn, costing the most in initial battery purchase, then why not make one?

Essentially, all an AC is doing is freezing some lines with a compressor, and then, blowing air over the frozen lines with a fan.

I saw this video on youtube and thought: "Why not?"

https://www.youtube.com/watch?v=D3YvF4eVQO0

The refrigerator that I'm looking at only uses 30 watts and has enough freezer room for two 1 gallon milk jugs. So I could have one frozen jug in the frig. and one inside the DIY AC on a continuous cycle for only 60 watts (including a 30 watt fan)!

Attachment not found.

The question here is: How to run the fan on solar since it's an alternating current fan? I figure there's no way to run it on your home system, but would a small stand alone system work? And how would you wire it?


Thanks.

vtmaps

Re: DIY Solar Air Conditioner

Your scheme won't work... think about this: You could just open the door to the fridge and put the fan in the fridge and blow all the cold air into the room. But that won't work either. Do you know why?

--vtMaps

waynefromnscanada

Re: DIY Solar Air Conditioner

Hahaha I love how the guy in the video puts the ice in an "ice chest" so it won't melt, then installs a fan to blow air through the insulated box to "force the cold out" and melt the ice. Sort of like dragging a huge rock behind my car to keep it's speed down so I'll bet better fuel mileage.

Cariboocoot

Re: DIY Solar Air Conditioner

And to explain it without sarcasm (unusual for me):

Air conditioners and refrigerators are both heat pumps. They move heat from one environment to another. In the case of an A/C the two environments are inside the insulated house and outside the house. In the case of the refrigerator they are inside the insulted box and outside the insulated box. If you remove the insulated barrier between the two environments all you end up doing is generating more heat.

I do wish people would stop relying on Youtube videos as a source of information. So much of the time they are instead a source of misinformation, confusion, and outright lies.

waynefromnscanada

Re: DIY Solar Air Conditioner

Cariboocoot wrote: »

So much of the time they (you tube videos) are instead a source of misinformation, confusion, and outright lies.

So well said Coot. It's so unfortunate that they so successfully mislead so many trusting people. Such a shame.

LandKurt

Re: DIY Solar Air Conditioner

Well, you could always put the refrigerator/freezer in a different room than the one you’re trying to cool to avoid violating any laws of thermodynamics. There is a different reason this doesn’t work as well as some would hope. Refrigerators aren’t really very powerful when compared to A/C units. Just note that a refrigerator runs at under 100 watts. How much cooling do you suppose you get from that compared to a room A/C pulling around 1,000 watts or a central A/C at 5,000 watts?

Have you ever noticed that big A/C units are sometimes rated in tons? The conversion is 12,000 Btu/h = one ton. They call it a ton because a cooling unit that size could freeze a ton of ice in one day.

From that you can see that 1,000 pounds of ice can cool a room about as well as a small 6,000 Btu/h window A/C running solid for 24 hours.

Therefore a one gallon block of ice weighing 8 pounds would cool a room as well as that 6,000 Btu A/C running for 11.5 minutes. That might help a little, but you’d really need a few blocks an hour to achieve much.