Sanyo Mini-Split AC

[mjp24coho]

I have been reading several of the threads here about the Sanyo Mini-Split AC units. I must admit - the unit sounds very appealing. I'm thinking of adding this unit into the solar system I'm designing for my off-grid cabin. However, after reading all the posts, I'm still a bit confused as to actual capacity of these units. I have a 2000 sq foot cabin, and am looking at the 9000 BTU window unit. I would prefer to run it on low (300W), to reduce draw on the inverter. How well would this unit cool the 2000 sq ft cabin on this setting, running for maybe 8 hrs per day (switched to be shut off other than the 8 hrs)? Would I need two units (one upstairs, one downstairs)? Typical summer temperatures are 85-95 degrees, but it quickly cools off at night.

Any insight would be greatly appreciated. Thanks.

[BB.]

For the price, I would be tempted to buy or borrow a basic "cheap" window A/C unit and try it in your place on a generator for a day or two.

The design of your building (insulation, shading, windows, etc.) are so critical to sizing of an AC system--I am not sure that we could give you more accurate information (but I live in a region where we don't need/have A/C--So I am not really the right person either).

A 2,000 square foot cabin is pretty large and a simple window A/C unit may be simply too small. Although, if the building is well sealed, it should help to reduce humidity (if that is an issue in your region).

-Bill

[Photowhit]

Wow so much to consider, Ambient tempuratures, Average day and night time, How much insulation, How well sealed, even the location of the outside unit. To my knowledge there is no window unit, perhaps you could provide a link. Being split units helps them be so effiecent.

But I'd say No chance... perhaps if you live pretty far north, where temps fall off well at night, with a well insulated place, good insulation here starts at R20 in the walls, there might be a chance.

[Photowhit]

Bill, dang your quick!

Sorry I missed your 10,000th post, was there a party?

Thanks for all the hard work!

-Whit

[Photowhit]

There's a Sizing Air Conditioners Work Sheet here.

Please note the preface on rooms.

[Vic]

I, too, am intriqued with the Mini-Split A/C concept, BUT I have no direct experience with the. Will probably add a two or three zone unit this summer at a new cabin being built now.

As Bill noted, a small window A/C would be an inexpensive experiment. A 6000 BTU window unit is what I now use for the bedroom, and it works well, but even for my 550 Sq Ft cabin it is not really quite adequate to cool the entire space (with its vaulted ceilings).

Just to make sure that you found the meatiest thread (IMO), be certain that you have seen this:
http://www.wind-sun.com/ForumVB/show...ght=Mini-Split

It would seem to me, that you would need a two zone unit, at the minimum.

In my situation, I am considering starting with an evaporative cooler (Swamp), as it can bring in cool outside air at night. If your humidity is fairly low, a Swamp cooler should use quite a lot less power than even the Mini-Split, and might be able to cool your entire space.

You might want to study company's site site noted in the above link:

Or engaging this company or another, is the exact configurtion of your cabin. And listen to their advice.

Dave Sparks, the Author of the above thread is often here, and can give you some real hands-on advice.

Good Luck, Vic

[mjp24coho]

Thanks for the input - this is all very helpful. I was originally contemplating a solar-panel fed evaporative cooler (Solar Chill - http://www.southwest-solar.com/door). Maybe that will be the better route to go. I like that it is fed directly from the solar panels, as I will only need it to operate for the hottest hours of the day when the sun is out. The cabin is located in Southern Utah - humidity isn't a real issue, and it's only needed for July and August. The cabin is a weekend retreat every 2-3 weeks.

Anyone have experience with these swamp coolers? I was contemplating doing a roof mount, possibly with the 42" version, or two of the smaller 30" coolers mounted in the walls.

[Vic]

mjp,

I have NO experience with these evap coolers, but, one advantage of a swamp cooler is its ability to bring in cool outside air at night. If the cooler is power only by solar, then this advantage is lost if there is no sun to run the cooler.

I've considered that at night one might be able to shut off the pump that supplies water to the pads, and just rely on the cool outside air to do the job.

YMMV and so on, Vic

[drees]

As the others have said - whether or not the mini-split will work will depend on environmental factors (primarily outside temp, how well insulated the cabin is and desired inside temp).

The mini-split will be the most efficient (aside from evaporative cooling if it's dry enough) - the question will simply be how many BTU you need to get the comfort level you are looking for.

The requirements can be anywhere from 10000 BTU per 500 sq/ft or as little as 2500 BTU per 500 sq/ft depending on those environmental factors (or even wider spread in extreme cases!).

[PhilS]

For over two decades we cooled with swamp coolers: a bigger one at one end of our 1000sq mobilehome and a smaller one at the other end.

After a particularly hot and humid spring, DW insisted I install "real A/C". I was preparing to buy a window shaker and planning to cut a hole in one wall to install it.

Then Dave's thread appeared. I bought and installed a Sanyo 1-ton mini-split.

Since we are totally off-grid, we had never let the swamp coolers run all day when we were at work. We'd come home to a VERY hot house. Then after an hour, it'd be 10 degrees cooler and a lot more humid inside.

Now the Sanyo is programmed to start about 10am and when we get home, the house is about 75 even tho it's over 100 outside. And NO humidity, which feels cooler yet.

I don't have specific Kill-a-watt readings. But I have absolutely NO doubt that this mini-split is using LESS power to keep the house cool versus the power that the swamp coolers used attempting to cool-down a warm house later in the day. IIRC it's about 750 watts constant (only one swamp cooler running ) vs 300 or less watts for the Sanyo.

The lack of noise has been a side benefit and much better than any window unit I could've found. Much of the time, other than seeing that the 'flap' is open, we can't even hear the Sanyo running.

Dry and cool air has been another benefit.

Since learning about these mini-split units, I notice them in every outdoor shot shown on the news from "developing countries". The rest of the world has been using them for many years and now WE are discovering them.

For your 2000sf cabin, your thought about one unit upstairs and one downstairs sounds to me like an excellent plan. I'd expect that you'll only use one of them most of the time.

Phil