Powering a 110v 10-20amp device

[atgblue1]

Hello,

I saw a DIYWorld video on youtube about a bike powering a treadmill motor to charge some batteries.

I am wanting to come up with a way to create enough electricity to power an air conditioner window unit (110v). IF it has to use home electricity to start up that's fine, as long as it can switch to the home-made electricity for a few hours at a time.

I'm just a little unsure about how things would work in reality and instead of making them only to perhaps see how they won't work, I'm hoping someone on here ( I thought it was gonna be the video dude), could give me some insight or if its already been done then point me in the right direction. (i'll research and learn etc, I'm just looking for some guidance to facilitate it )

I've thought about using a battery bank large enough to run the unit on and then use something similar to the bike with the alternator to charge the bank. I'm just wpndering, if I was using such a bank, would the pedaling/energy-input required to keep the air unit running be SOOOOO hard and strenuous that its not feasible? or with step-up gears and stuff ( like on bicycles), could it become not-so-hard to generate the rpm's etc?

And fyi, I'm NOT looking for "free energy" thing or "change the world" invention. Just a Do-it-yourself redneck contraption to make some electricity and save a few hours of money at a time, I.E using an air conditioner for a few hours at night for free (from the bank or whatever).


TLDR: I wanna power an air conditioner unit for a few hours at a time off-grid. (save money). How could I go about doing that?


thanks!

[techman]

Hi, this is Troy, "the video dude".

Here are some details for you to consider. The average person can only sustain about 300 watts of power on a pedal powered generator for any amount of time. Lets say you pedal for an hour. This gives you about 300 watt hours of usable energy. You can power a 300 watt device for an hour.

Now, my little air conditioner uses 500 watts. Most AC units use a lot more than that.

You would need to pedal about 1.5 hours to run the AC for about an hour. Probably double that for losses in the wires, generator and batteries. We do not live in a perfect world.

So, theoretically you need to pedal about two hours for every hour of air conditioning. I am not sure it is worth using a bike to do this.

But depending on where you live, you may try a cheap and simple homemade AC unit using a fan, water pump, cooler and some ice.

Run some coils of copper tubing around the front of a box fan. Run some silicone tubing from the copper tubing down into a cooler which can hold ice water. Get an aquarium pump and put it inside the ice water. Turn on the fan and the pump and feel the cold air blowing on you as the icy water circulates in front of the moving air from the fan.

This will not cool down a room very much but does give you a nice localized cool environment. For best results have it blowing right at you where you are sitting or working.

I did this a few years back and it worked very nicely. I should do it again this year as a demonstration. Only problem with me is that I am always on the move and working all over the place so it is not so convenient for me.

Now with this setup you will need a lot less power to run the homemade AC unit.

Lets say the fan uses about 50 watts and the water pump uses about 10 watts. Lets round this all off and say you need 100 watts to run your homemade AC unit.

This gives you three hours of run time on an hour of pedaling your generator.

You could run all of this on a single deep cycle 100 amp hour battery for roughly about 12 hours before you have to pedal again.

Let me know how it goes.

[atgblue1]

Hey! thanks for the reply, sorry for the delay.

its a bit less efficient than what i was hoping for, honestly i wasn't planning on using a bike, but my idea usually gets a lot of hate/flame from non-believers and non-visionaries. seeing that people on here are a bit more open i'll post a thread about my plan beleiving is the biggest part yes?

[techman]

Yes believing is important but then again there are people out there who intend to "disprove" any sort of alternate energy.

I look forward to seeing your plans.

[Firechief301]

To add to Troys post there is a nice product on the market today that makes the DIY air conditioner a better choice. I can't remember who did the you tube video but they are using a simple solar set up hooked to a portable ice maker. With the cooler type DIY air conditioner using minimal power for the fan and not having to pump water through the device and the quantity of ice the video shows him making you could create lots of cold air.

[techman]

I once used a fan with a cooler full of ice water as a sort of DIY air conditioner. I coiled copper tubing in front of the fan and ran that into the ice water with a 12 volt water pump. The fan blew cold air into my face. And thats all it did. You could feel it only if you sat right in front of it. It did not change the temperature in the room a single degree. On a bad note, all that melting ice raises the humidity in the air and makes the hot feel worse.

Not trying to burst your bubble but just sharing my own experience.

I have noticed though that just taking out the humidity from the air makes it feel so much nicer inside.

I hope to make a dehumidifier using a Peltier like those used in a portable cooler for a car. A fan, heat sink and a peltier should take the moisture out of the air. One side freezes while the other side gets hot. Put the hot part out through the window like an AC unit. The cold side indoors with a water collector underneath it. Have a timer to turn it on and off occasionally. Off allows the frozen water to drip off the fins. Turn it on and water from the air collects on the fins again.

Only downside is it takes 75 watts continuous to run. Upside is that its less than the 500 watts an AC unit uses.

[AlOlmstead]

The formula that I use for balancing AC draw against DC supply is:

(AC Watts Needed / 10) * (1.1 fudge factor) / (DC amps per power source) = number of power sources

e.g.: If a set of solar panels produces 5.25 amps and I need 800 AC watts:

(800 / 10) * (1.1) / (5.25) = 16.8 or 16 power sources

FYI: given the 10-to-1 ratio of DC to AC, any AC device that makes a lot of heat or cold will require HUGE DC source(s).