Inverter window ac

[SALIV8]

Well looks like technology finally caught up with the window shakers. Anybody have one yet?

https://www.midea.com/us/Air-Condit...0,000-BTU-U-shaped-Air-Conditioner-MAW10V1QWT

 

[mike93lx]

That u shape is interesting.

No experience with their a/c's, but I have two midea dehumidifiers that I like a lot

 

[TonyG109]

I don't have one of these, but if I was in the market for one I'd definitely consider the unit for the inverter technology alone. The claimed noise reduction and the seemingly superior window seal at the bottom of the sash are huge pluses over the typical window unit.

The manufacturer's claim that you can still open the window is, IMHO, not a justification for buying this design for two reasons. First, there is no mechanism to lock the window except the old fashion method of screwing an "L" bracket to the top sash to hold the bottom sash shut. Second, you still have the issue of air flowing in/out of the house between the two sashes. A foam seal is still required to be placed in the gap.

All in all, I would still give this model a test drive because of the inverter technology, improved seal and an available phone app to control it. But my flag is still planted in the mini split camp if it fits your situation and budget.

 

[Old Man Roger]

I'm a little confused, don't inverters usually convert DC power to AC? What's the advantage here?

 

[mike93lx]

I'm a little confused, don't inverters usually convert DC power to AC? What's the advantage here?

Inverter drive compressors can vary output, throttling down when full power isn't needed. Same as most mini splits and some microwaves

 

[theoldwizard1]

I'm a little confused, don't inverters usually convert DC power to AC? What's the advantage here?

Inverter drive compressors can vary output, throttling down when full power isn't needed. Same as most mini splits and some microwaves

Specifically, the incoming AC power is converted to DC. The DC is then converted to 3 phase AC. This gives you a few advantages :

• "synthesized" 3 phase allows variable speed by changing the frequency
• 3 phase AC motors are MUCH more efficient than single phase
• Bonus - once you have the electronics "on board", it is very easy to add in TRUE "soft start". (Not just a big capacitor.) This would allow a bigger motor to run on a typical 120V@15A circuit without tripping the breaker.

This concept is not new, but the technology to do it inexpensively did not exist 20-30 years ago.

Also realize, that motor is designed to work on a much lower voltage than your typical 3 phase motor. Probably less than 100V.

 

[Old Man Roger]

Inverter drive compressors can vary output, throttling down when full power isn't needed. Same as most mini splits and some microwaves

Specifically, the incoming AC power is converted to DC. The DC is then converted to 3 phase AC. This gives you a few advantages :

• "synthesized" 3 phase allows variable speed by changing the frequency
• 3 phase AC motors are MUCH more efficient than single phase
• Bonus - once you have the electronics "on board", it is very easy to add in TRUE "soft start". (Not just a big capacitor.) This would allow a bigger motor to run on a typical 120V@15A circuit without tripping the breaker.

This concept is not new, but the technology to do it inexpensively did not exist 20-30 years ago.

Also realize, that motor is designed to work on a much lower voltage than your typical 3 phase motor. Probably less than 100V.

Ahhh ok. So my su2000 Honda generator, could run a bigger window unit if it's an inverter type.

 

[mike93lx]

Ahhh ok. So my su2000 Honda generator, could run a bigger window unit if it's an inverter type.

Not necessarily. It may be easier starting and will use less power sometimes, but max draw may still be beyond the generator's capabilities

 

[Old Man Roger]

Not necessarily. It may be easier starting and will use less power sometimes, but max draw may still be beyond the generator's capabilities

Isn't the biggest draw during start up?

 

[Old Man Roger]

Lets say my su2000 can run an old school 10000btu window shaker, I would assume it could run a higher btu inverter type?

I pulled the 10000btu number out of thin air, for the sake of the conversation, I don't really know the capability of my su2000

 

[mike93lx]

Lets say my su2000 can run an old school 10000btu window shaker, I would assume it could run a higher btu inverter type?

I pulled the 10000btu number out of thin air, for the sake of the conversation, I don't really know the capability of my su2000

It may not. It depends on the limitation being startup or running load. The inverter may lessen startup load by enough to make the full speed running load higher.

I would guess that it could run a higher rated inverter unit, but you'll need to get draw figures to check, or test it

 

[CoogarXR]

Looks like a cool advancement in technology (totally unintentional pun).

 

[Old Man Roger]

It may not. It depends on the limitation being startup or running load. The inverter may lessen startup load by enough to make the full speed running load higher.

I would guess that it could run a higher rated inverter unit, but you'll need to get draw figures to check, or test it

Well that seems completely pointless then. They look to be about 5 times more expensive than an old school window unit, if the full speed running load were greater than the same size old school unit, then what would be the point?

 

[mikecmd]

I purchased a 12000 BTU Midea AC, nice looking and very quiet.
Only problem with it is that it does not output 12000 BTUs of cooling, only goes to ~400 watts which is equivelent to around 6000 BTUs - very frustrating

 

[mike93lx]

Well that seems completely pointless then. They look to be about 5 times more expensive than an old school window unit, if the full speed running load were greater than the same size old school unit, then what would be the point?

It can throttle back. Resular a/c's have to run full speed the whole time and switch on and off. Inverters are superior since you generally don't need full tilt at all times

 

[Old Man Roger]

It can throttle back. Resular a/c's have to run full speed the whole time and switch on and off. Inverters are superior since you generally don't need full tilt at all times

Ok I see what you're saying now. So the main advantage is that it's just cheaper to run.

 

[mike93lx]

Ok I see what you're saying now. So the main advantage is that it's just cheaper to run.

And quieter.

Basically the same advantage of your eu2000 over a traditional geberator

 

[Bigbandguy]

While it would require a window sized hole it seems to me that the unit could be installed as a through the wall install with an insert built in place of the window. That could be both solid, weather tight and secure. It is certainly cheaper than a mini split yet has some of the advantages.

 

[Bert_]

While it would require a window sized hole it seems to me that the unit could be installed as a through the wall install with an insert built in place of the window. That could be both solid, weather tight and secure. It is certainly cheaper than a mini split yet has some of the advantages.

I would never install a window unit through a wall. They are just about impossible to seal and flash properly. I have seen several leak water and you are going to have to cover with plastic in the winter to keep the drafts away.

My house had one mounted in the wall when I bought it. I removed it and now use the same A/C in a window. I pull it out in the winter.

 

[Bert_]

I bet they are pretty good. I would consider one if I didn't love simple technology so much.

 

[david594]

Well looks like technology finally caught up with the window shakers. Anybody have one yet?

https://www.midea.com/us/Air-Condit...0,000-BTU-U-shaped-Air-Conditioner-MAW10V1QWT

After almost a 4 week wait for amazon to deliver i've had the Midea 8k BTU U Inverter model for just about a month now and generally love it. This is the change the window AC market has been waiting for.

It's quiet! To the point that if there is even mild ambient noise I need to listen carefully to tell if it is on.

The inverter compressor does seem to have a soft start function as you can hear it slowly wind up when the compressor is called for.

I wish I had an ampmeter to put on it to see what it draws.
It had no issues running for me two weeks ago off a Honda 6500 watt construction generator only putting out 58 hz. And I have an EU2200i coming that I expect it will have no issues running.

For us the 8k Midea replaced an older Frigidaire 5k 13 seer unit. The Midea definitely puts out more cold air so I have no concerns regarding the output. It is also markedly quieter than the frigidaire.

 

[SALIV8]

After almost a 4 week wait for amazon to deliver i've had the Midea 8k BTU U Inverter model for just about a month now and generally love it. This is the change the window AC market has been waiting for.

It's quiet! To the point that if there is even mild ambient noise I need to listen carefully to tell if it is on.

The inverter compressor does seem to have a soft start function as you can hear it slowly wind up when the compressor is called for.

I wish I had an ampmeter to put on it to see what it draws.
It had no issues running for me two weeks ago off a Honda 6500 watt construction generator only putting out 58 hz. And I have an EU2200i coming that I expect it will have no issues running.

For us the 8k Midea replaced an older Frigidaire 5k 13 seer unit. The Midea definitely puts out more cold air so I have no concerns regarding the output. It is also markedly quieter than the frigidaire.

Glad to hear. Thanks for the detailed response.

 

[david594]

The wifi has also been fairly reliable on it. And the app is a little rough but very workable.

The remote is ok. I dropped it behind the bed a week ago and it has remained there since because the App does a decent enough job overall.

Ours is in the bedroom and keeps the room at 65 all night for comfortable sleeping, and then at 5:30 AM turns up the temp so the room is fairly warm come wake up.

Biggest complaint is that the exterior bracket seems to be one size fits all for their 3 model sizes. So the bracket is clearly way bigger than it needs to be for the 8k model.

 

[Bigbandguy]

I would never install a window unit through a wall. They are just about impossible to seal and flash properly. I have seen several leak water and you are going to have to cover with plastic in the winter to keep the drafts away.

My house had one mounted in the wall when I bought it. I removed it and now use the same A/C in a window. I pull it out in the winter.

Years ago I lived in an apartment complex that had 17000 BTU Window AC's mounted through the wall in each apartment. They were properly installed, drained well, had good flashing etc and did a fine job of cooling the small apartments.The units had central heating and I guess the AC units were added later. Through the wall works fine if the installation is well done. I think these new inverter units may be really good for a small workshop and other situations where a central unit is unavailable or inadequate.

 

[Bert_]

Years ago I lived in an apartment complex that had 17000 BTU Window AC's mounted through the wall in each apartment. They were properly installed, drained well, had good flashing etc and did a fine job of cooling the small apartments.The units had central heating and I guess the AC units were added later. Through the wall works fine if the installation is well done. I think these new inverter units may be really good for a small workshop and other situations where a central unit is unavailable or inadequate.

If someone can tell me how to do it right I'm all ears.

I don't see any way to install head flashing or lap over the water restive barrier at the bottom.

 

[jjrbus]

I will be watching these, when the minis bite the bullet the inverter window installed in a wall may be the next step. I took a peak at one but is physically too large for my RV.

 

[theoldwizard1]

Ok I see what you're saying now. So the main advantage is that it's just cheaper to run.

You guys danced all around the "starting" current issue without EXACTLY hitting the nail on the head !

ALL generators have a hard time starting a heavy load like an air conditioner. A large starting capacitor (as used on conventional A/C units) helps but it also hurts if you have limited "instantaneous" power available (generator). Inverter A/C units also have large capacitors. An uncharged, large capacitor "looks like" a short circuit which is why the "in rush"/starting current is so high.

What is required is a device that limits the current charging a completely discharged capacitor. The capacitor will still charge up but it will take 100s of msecs instead of <10msecs. Of course, the device has to "get out of the way" once the capacitor is charged up ! Because inverter A/C already have a lot of electronics on board, adding such a device when the product was being designed would only cost a few dollars. Some have this, some do not.

This company makes one MicroAir EasyStart soft starter

If you want more gory details on what I said watch this video How to make a soft starter

 

[LS6 Tommy]

Well that seems completely pointless then. They look to be about 5 times more expensive than an old school window unit, if the full speed running load were greater than the same size old school unit, then what would be the point?

$400 for a 10k window unit is not 5 times more expensive. It's exactly the same price as any good 10k unit I would buy.

If I had a need for a new window unit, it sure looks like what I'd get.

Tommy

 

[Old Man Roger]

$400 for a 10k window unit is not 5 times more expensive. It's exactly the same price as any good 10k unit I would buy.

If I had a need for a new window unit, it sure looks like what I'd get.

Tommy

Ya I just did a quick google search, the $100 units were very likely low quality, and the inverter style units I saw were in the 5 and 6 hundred dollar range.

 

[dogdog]

Anyone got that Midea 12000 inverter unit ? How heavy is that thing and how is it performing?

 

[u3b3rg33k]

You guys danced all around the "starting" current issue without EXACTLY hitting the nail on the head !

ALL generators have a hard time starting a heavy load like an air conditioner. A large starting capacitor (as used on conventional A/C units) helps but it also hurts if you have limited "instantaneous" power available (generator). Inverter A/C units also have large capacitors. An uncharged, large capacitor "looks like" a short circuit which is why the "in rush"/starting current is so high.

What is required is a device that limits the current charging a completely discharged capacitor. The capacitor will still charge up but it will take 100s of msecs instead of <10msecs. Of course, the device has to "get out of the way" once the capacitor is charged up ! Because inverter A/C already have a lot of electronics on board, adding such a device when the product was being designed would only cost a few dollars. Some have this, some do not.

This company makes one MicroAir EasyStart soft starter

If you want more gory details on what I said watch this video How to make a soft starter

it seems to me about half the VFDs I run across have a circuit to limit inrush, and half don't. I'm betting this does to avoid "issues". It'll also have filtering to keep the inverter from tripping GFCIs.

it may be a "DC inverter" meaning permanent magnet rotor - that's what my washer is.

Generally speaking, a properly configured VFD will pull nameplate amps to start up a compressor. set up for constant torque and not to exceed 100% load. pretty easy to do on most things with a <3s ramp to minimum Hz.
I have a 10hp 3 phase VFD V4 piston compressor at work, and at all times running loaded it's outputting 22-23 Amps - just the voltage that varies with the RPM.

 

[iced98lx]

I've got a pair of LG units with inverters (14kbtu) and they are quiet, effective, and have been trouble-free for the last 12 months or so. The U shaped ones were my first choice because of their format but they were not in stock when I wanted them last year. No regrets on the LG's despite my opinions on their fridges.

This is the unit I have two of: https://www.lg.com/us/air-conditioners/lg-lw1517ivsm