DC / AC Inverters

If you have an AC unit that is less than 3000W, then yes. But that is typically a very small room type AC unit, and you would not be able to run anything else. You would also need to check your inverter's "surge capacity" to see if it can start the compressor motor. You may be relegated to a much smaller AC unit, like maybe 1500W.

If so, huddle everyone into the bathroom to stay cool!

I was going to respond...but once I read JReaf's response, there's not much else to say... ...But GA.

Just keep in mind what this will do to your poor batteries.

Regards,
Sapper

too waste. in general, it can only use to last for 30minutes.

unless you live at an outpost.

why not link a long distance wire to plant?

Here not only the inverters matter but the stored energy (ie batteries)

3000W ie 3KW inverters are OK (since my room AC-1.5T if I am not wrong must be 1.5KW and it cools a 15x15 ft room well) but how do you get the storage cels to store the power ?

Get portable gensets of lower KW may be a far better and efficient solution.

Hi

Most inverters (US) are 120 VAC. You would need to run a pair in series or get a 120/240VAC transformer. Magnum makes a 120/240 inverter. But that is besides the point. An inverter is only part of the equation. What creates the power? Solar? Wind? Hydro? A PV (solar) system to run a 3kVA load 5-6 hours a day would run $15,000-$20,000. (Not including local, state and Federal rebates.) $15,000 would go a long ways towards better insulation, putting in geothermal cooling, using vegatation, etc. to be more comfortable. Or, if your using the RV to supply the power, you might be better off staying in the RV.

Dear Wayne

(a) Pls check the capacity of AC required, for the cabin size.

(b) Accordingly the inverter capacity will be decided. As has already been answered, the inverter should be suitable for motor duty application because motor will draw higher starting current, till it reaches its speed.

(c) Decide how many hours the AC will be running.

(d) According to the running time of AC, battery capacity will be decided. I am sure it has to be of 48 V, still higher, better ( I donot know the regulations in your country to use higher DC voltage, so accordingly care needs to be taken ). Higher battery voltage will result in lower current for the same power and therefore less power loss and hence higher operating efficiency.

(e) Decide how would you charge the battery. If you are looking at solar PV, then

(1) Please check the area required to mount solar panels & associated equipment.

(2) If you choose to operate AC even during non-sunshine days, then decide the backup time for which battery has to provide power to AC through inverter. According to this time duration, battery capacity will increase furthermore.

(f) If you choose to operate the AC directly on solar PV, without battery, then system requirements change. Disadvantage is that the AC will trip whenever solar power is not adequate to drive the AC.

(g) If wind speed in your area is good, then you could consider small wind generator also. In this case, check about all round clearance for assembling and dis-assembling the wind generator.

(h) Last but not the least, investment?

Thanks and regards

Ashok Toshniwal, Bangalore, India

The short answer is yes. However there is no free lunch. A remote cabin in Montana means you are a long way from any power source. The cost of bringing in either solar or wind power in sufficient capacity to actually make this work is going to be astronomical. For that amount of money you can do much better with other choices. Can you drive a big truck up to the door or is this horse back access only?

But let me ask a philosophical question. Why spend the money to buy a get away from it all place if you then insist on bringing it all with you?

For moderate cooling look up swamp coolers. I assume you have a source of water.

A 3000 watt inverter will drive a fair size A/C unit. I have designed such systems. At trade shows I have sucessfully run 5600 BTU and 9000 BTU air conditioners using a truck battery and a 1200 wat inverter. This was to demonstrate our product line. BUT the battery does not last long. So how are you going to recharge it? .. . .. Aye that's the rub, isn't it.

There are a number of solutions, all of which cost plenty of $$$. And there are plenty of companies that will sell you these expensive solutions complete with elaborate promises.

I moved into the mountains two summers ago. Despite hitting over 100 F for days on end, on several ocasions; we never did feel the need for air conditioning. Kind of defeats the whole purpose of getting away from it all. Swamp coolers, fans etc and of course insulation plus efilm on windows, go a long way to mitigate the need.

But if you really want to know how, send me an email.

You have some good answers already, but the short answer is a Petrol or Diesel ndriven alternator supplying your AC with AC. Batteries are not a serious option as even if you have the 500lbs of batteries, you still need the Generator to put a charge in them!!

Also, what nobody has mentioned is that lead acid batteries are only about 70% efficient with charging, discharging and inverters are at best( at best!!) 85% efficient, so you will be working at around 55% total efficiency........at best....

If you ever accidently over discharge any of your batteries (assuming NOT leisure type) then you will be buying a new battery or two in a short space of time.....

When the sun goes down... (outside temp is less than inside temp) we open all windows to let the cool air in. In the morning, when temps rise, we lock the place up tighter than a drum. Keep the cool air in. I do concede that we use a window fan to suck the cold air in during the night... coldest air is around 6:00 am, but it is much cheaper than air conditioning.

Of course I have had to train my daughter that because it is Warm inside, you DO NOT turn on the fan and suck in the HOTTER THAN HELL air from outside. I assume that in Montana, you have reasonable insulation in your cabin. Insulation works both ways.

ALOT cheaper than air...

Bill