Electronic Water Cooler?

[chemelec]

you're right , what if i have a 5 gallon reservoir? with a small aquarium water pump?,,, my main consideration is a peltier,,,it can be overused?


thanks Sir Nigel fo continous replies

It will NEVER Cool 5 gallons of water much more than one or two Degees.
And you would need a VERY Well INSULATED Tank.

 

[bhong2002]

okay, i have a mistake of saying a "mini-airconditioning" what i really want to say is a mini room air cooler, just like some manufacturer does

https://www.kaitousa.com/roomconditioner.htm

or,,, should i give up?

 

[Nigel Goodwin]

okay, i have a mistake of saying a "mini-airconditioning" what i really want to say is a mini room air cooler, just like some manufacturer does

https://www.kaitousa.com/roomconditioner.htm

or,,, should i give up?

I should give up the idea of using a peltier device!. Using a fan across a block of ice would work, but it's essentially just moving the heat pump to your freezer.

 

[bhong2002]

thanks....

i give up

 

[Oznog]

Well you don't need to "give up". Just rethink what you want to do and make a more workable project goal.

A common Peltier may suck up to 20W of heat out of the cold sink if there is only a small temp differential. But it will heat up the hot side with 40W of heat. So it can make only localized cool spots in the room at the expense of making hotter areas.

"portable" A/C units all have a hot-air exhaust hose that blows out a window. There are also evaporative units which are neat in that they don't take a lot of power and don't have a hot air exhaust. However, they cool by increasing the humidity in the air. There are limits to how much cooler this can make the air and will only work on the same air once or twice because it increases the relative humidity to a point where further evaporation won't work and the air gets really muggy. Sweat won't dry off you and the inside of a building can mildew.

 

[justDIY]

I seem to remember a few years back, some American kids won some prestigous design award for "inventing" a peltier based air conditioner ... IIRC it was intended for the automotive industry. --> link here **broken link removed**

so, it is possible, but I think the facts stated by the students are unfounded ... they're replacing a realtively efficient phase change heat pump with a very inefficient semiconductor pump ... saving a few pounds of HCFC's from the compressor and producing a lot more Nitrogen and Hydrocarbon emissions out the tail-pipe instead

Oznog's "swamp blower" is the best in terms of cheap cooling, and will work well if you live in a dry climate ... no dice here where I live, the humidity is already 60%+ during the warm months. Nigel's ice + fan dates back to the very earliest of air conditioners and is a proven method ... except its still wasteful - the energy required to freeze the ice out-weighs the energy a vapor cooling system would use... since what will you use to freeze the ice in the first place, why a vapor system of course!

 

[bhong2002]

oh, there's still hope for that!, i suppose to make a design a water tank & how to rotate a coll water on alluminum tubes,,, i'll post whatever happens on this project!,, thank you all GUYS ,,,

regards BHONG

 

[bhong2002]

i forgot to ask to mr. JustDIY, what is DIY means??

 

[justDIY]

I've got a couple ideas on re-creating the drinking water cooler, but sorry, nothing for a mini room cooler... peltier just isn't strong enough.

but hey, if you work somewhere you can get lots of free ice and/or someone else is paying for the water, here's an idea for you:

**broken link removed**

 

[Oznog]

I seem to remember a few years back, some American kids won some prestigous design award for "inventing" a peltier based air conditioner ... IIRC it was intended for the automotive industry. --> link here **broken link removed**

so, it is possible, but I think the facts stated by the students are unfounded ... they're replacing a realtively efficient phase change heat pump with a very inefficient semiconductor pump ... saving a few pounds of HCFC's from the compressor and producing a lot more Nitrogen and Hydrocarbon emissions out the tail-pipe instead

Well what they really neglected to cover is the scale of the technology. A car AC system typically requires an obscene amount of BTUs for its sq footage. I don't know of any mfg BTU figures but I believe something like 20,000 BTU for a sedan. So look at some typical examples: https://www.mpja.com/viewallnopict.asp?dept=60&main=
would require over 100 of the biggest ones, and would need 10HP. But that BTU figure is probably for zero temp difference, for temp differences of say 95F outside and even 75F inside the pumping capacity is far lower and far more devices would be required. The sheer size would be prohibitive, and it's incredibly difficult to remove that much heat without raising the hot side temp and losing all your efficiency.

As a more practical example, look at this product of an equipment cooler:
**broken link removed**

By the current listed, it's 420W, 29 lbs, and moves 800 BTU, but look at the "Thermal Performance" chart. It can move 800 BTU out of the case when the case is 20F hotter than the outside (this is still useful because it prevents air exchange and contamination inside the equipment). In a case where you used it as A/C in the summer at 95F outside, and want an interior to 70F, this device can move about 90W of heat out. Some car stereos make more than 90W of heat. A single sq ft of midday sunlight is more than 90W. In reality you might need 100 of these devices to yield a result similar to a conventional car A/C, and can consume most of the hp the engine was capable of putting out making your mpg absolutely atrocious.

 

[bhong2002]

Thanks for another exciting ideas Sir Oznog & Sir JustDIY that was a preety cool sites, i am now looking for the materials & tools for my project