Window AC: to replace or not to replace

[Rand]

I really wish they made one with heat too. My basement garage is is below grade on 2.5 sides, well insulated and underneath a living space so it has minimal cooling and heating requirements. I think a 12 or 18k would be just right for me but would really like heat too. As cheap as the 12k AC is, I should give it a shot.

mr cool diy mini split heat pump? basement/garage install seems like it would be easier than some installs.

 

[RhondaHonda]

mr cool diy mini split heat pump? basement/garage install seems like it would be easier than some installs.

Yeah, that’s been on my radar for a few years now, I just haven’t pulled the trigger. They are definitely cheap enough and I’ve read the instructions multiple times.

I don’t use it much but it would sure be nice to have it fully climate controlled.

 

[alarmguy]

his current 6000btu runs for hours and hours and doesnt provide enough cooling.

Midea unit is not grossly oversized. inverter compressor can speed up and slow down.
the 12k btu unit can easily go below 4k btu

my 8k unit has a range of about 96w to 500w. I'd expect the 12k unit to run aprox 150w to 800w

Agree but we dont know the room dimensions so your saying 12k is not grossly oversized but we do not know that.
He has a 6000 but of unknown age and working condition, doubling it to 12,000 doesnt make it right without more information and it can be grossly oversized.

An 8000 BTU unit has almost 35% more cooling capacity than a 6000. That is pretty significant, in his OP he already states his 6000 BTU cools a room down into the 60s in less than 4 hours. That is massively significant and actually oversized to todays standard cooling requirements in new home construction, the unit would not run long enough to get rid of moisture in humid areas and could turn into a health hazard for mold to grow. There is a formula that a large HVAC company can educate on that formula. But it takes a lot of data into the formula in selecting BTU size. I know one of them creates a disclaimer now that units are designed to cool to 75 degrees as part of a warranty. 72 might be possible. Mold is part of the reason. But I am not by any means an expert on any of this other then instructed quickly by a large HVAC company.

He also states it keeps up on hot days. Adding 35% more BTUs to 8000 sounds very significant and if he is in a humid area I would consider 8000 the MAX BTU based on his post.

 

[Rand]

Agree but we dont know the room dimensions so your saying 12k is not grossly oversized but we do not know that.
He has a 6000 but of unknown age and working condition, doubling it to 12,000 doesnt make it right without more information and it can be grossly oversized.

An 8000 BTU unit has almost 35% more cooling capacity than a 6000. That is pretty significant, in his OP he already states his 6000 BTU cools a room down into the 60s in less than 4 hours. That is massively significant and actually oversized to todays standard cooling requirements in new home construction, the unit would not run long enough to get rid of moisture in humid areas and could turn into a health hazard for mold to grow. There is a formula that a large HVAC company can educate on that formula. But it takes a lot of data into the formula in selecting BTU size. I know one of them creates a disclaimer now that units are designed to cool to 75 degrees as part of a warranty. 72 might be possible. Mold is part of the reason. But I am not by any means an expert on any of this other then instructed quickly by a large HVAC company.

He also states it keeps up on hot days. Adding 35% more BTUs to 8000 sounds very significant and if he is in a humid area I would consider 8000 the MAX BTU based on his post.

you appear to be missing my point.
if his 6000btu unit runs for AT LEAST 3-4 hours without shutting off.
and the new one is an INVERTER COMPRESSOR
Please go research what an inverter compressor is.
it can output aprox 2500-12k btu. IT is NOT oversize.

Also I'm not sure what you are agreeing with because its certainly not anything I said.. as you are arguing points that just arent true.

if 6000 btu isnt oversize.. and taking 4 hours to cool a room to a comfortable level I'd say not
a variable compressor that can put out as low as 2500btu is not oversize either.

 

[Rand]

its that time of year, for the danby to go back in the window. (rebadged midea even the app works)
I may seal it up with a little plastic wrap. but it might go in and out of the window if I wont need it at least once in a week (spring)
blanket is just there temporarily to block light while I'm sleeping until its in for the summer.

upstairs office/spare bed, small cape cod home the roof gets it meltingly hot up there.

currently 82f in room, set to 60f, pulling 400w.

Downstairs (main floor) its only 71f even with the windows opened up all afternoon
basement 60f.

 

[alarmguy]

you appear to be missing my point.
if his 6000btu unit runs for AT LEAST 3-4 hours without shutting off.
and the new one is an INVERTER COMPRESSOR
Please go research what an inverter compressor is.
it can output aprox 2500-12k btu. IT is NOT oversize.

Also I'm not sure what you are agreeing with because its certainly not anything I said.. as you are arguing points that just arent true.

if 6000 btu isnt oversize.. and taking 4 hours to cool a room to a comfortable level I'd say not
a variable compressor that can put out as low as 2500btu is not oversize either.

My MISTAKE (it happens)
I missed the reference to inverter

 

[Rand]

my 8000btu is current set on 73f (it had crept upto 78f inside)
and is using 105w-110w to maintain 73f not bad with 600w of computer and lights on.

PS: TPLINK KASA plugs with energy usage are nice.. much more convenient than killawatt meter.
I have them on a separate locked down wifi.
also at that power level it produces much noise as a fan on low/med. Nice if you are sleeping 5ft away.

 

[JHZR2]

This is true. It runs at only the output necessary. The thing works exceptionally well.

I've been running it in the bedroom for the last 4 hours, set at 63 degrees, just to see what the current draw will be. It is now drawing 430W and it's too cold in there! If I remember, I'll check again in the AM. It does go down to about 300W sometimes. Which I assume is about 6000 BTU.

You have to screw it into the window, no? Thereby essentially ruining the window. And since. Window ACs are ugly, removal and reinstallation will be an issue as the screw in and out will damage the holes.

Is that correct, or just hearsay?

 

[Rand]

You have to screw it into the window, no? Thereby essentially ruining the window. And since. Window ACs are ugly, removal and reinstallation will be an issue as the screw in and out will damage the holes.

Is that correct, or just hearsay?

incorrect. Although you can have many fitment issues for edge cases/odd windows.. it fits fine in most standard type windows.
I have to remove the window handle from the front of the window -2 screws so it will slide into the U shape.
the support bracket gets 2 tiny screws into the wood frame around the window I've had it in and out 20x and same tiny screws work fine.
You could likely wedge these with a couple pieces of wood and not even use screws if you had some type of exotic window ..once the unit is on the bracket and the window closed its not going anywhere.. the expanding front part of the bracket is very stable.. even without screws as The front bracket expands wider than the window opening.

 

[goblin]

You have to screw it into the window, no? Thereby essentially ruining the window. And since. Window ACs are ugly, removal and reinstallation will be an issue as the screw in and out will damage the holes.

Is that correct, or just hearsay?

The only thing to screw in the window is a lock, and it's an optional step.

There are other screws that have to be screwed but those goblin the hardware provided with the AC.

It's less destructive than a classic window unit.

 

[JHZR2]

incorrect. Although you can have many fitment issues for edge cases/odd windows.. it fits fine in most standard type windows.
I have to remove the window handle from the front of the window -2 screws so it will slide into the U shape.
the support bracket gets 2 tiny screws into the wood frame around the window I've had it in and out 20x and same tiny screws work fine.
You could likely wedge these and not even use screws..once the unit is on the bracket and the window closed its not going anywhere..
and the expanding front part of the bracket is very stable.. even without screws. The front bracket expands wider than the window opening.
View attachment 274716

Incorrect… but you DO have to screw into your woodwork?!?!??

I’m trying to not screw into anything. My 3-month window units don’t screw in anywhere. Zero damage.

These units are very tempting compared to more mini splits in my home. We don’t use AC much…

 

[goblin]

How do you lock your windows after the units are installed?

 

[Rand]

Incorrect… but you DO have to screw into your woodwork?!?!??

I’m trying to not screw into anything. My 3-month window units don’t screw in anywhere. Zero damage.

These units are very tempting compared to more mini splits in my home. We don’t use AC much…

ok so word choice on your part and my part were not exact enough I think

You have to screw it into the window, no?

you asked if you had to screw into a window and ruin a window? the answer is no
2 tiny screws into the woodwork which imo are optional at least with my window type.
The screws could be replaced with a piece of wood.. or nothing.
the bracket is extremely stable and works excellent even just resting on the outside against my vinyl siding.

There is also a sliding brace that slides out in the u section to the side of the window
so the AC can go nowhere. it requires 2 screws.. to lock it into place these go into the brace and brackets on the ac
not anywhere on the window. but you could just slide them out and it locks the ac into the window.. I dont even use mine. its not going anywhere with the window closed.
and it barely fits in my window(width) so its a pain to get a screwdriver in there but doable.

edit: I added more to post @JHZR2

If you are thinking about replacing regular window ac with these.. they are a winner. I'd buy another tomorrow full price if this one dies... that much better.

 

[John105]

The condenser's water would then pool at the bottom, needing a pump. Also, my walls are nearly a foot thick.

Last night:

Initial power draw 604W
Later on 430W
Before bed 320W
This AM 270W

Bedroom Temp 62.7 this AM.

I'll be honest, I believe this window unit is more efficient overall than my 16 SEER home central AC. The home AC has a 2.5T and a 5T compressor, runs constantly and the 2.5T unit does only slightly better at cooling the entire house on modest days.

Put another way, I am quite sure 3 of these units could cool my home during the hottest summer days and use less power doing so. My 5T unit draws about 3700W at full load. The advantage is that the central air is completely silent and has superb filtration.

I don't know much about window units as I moved into a house with central AC in 2002 and now can't be without it (1990-1998 I did not have AC in anything--car, apartment, etc., and I was just fine). But because we got a new system in 2020 with an app, I can see that on the worst days of the worst, the system runs 11 hours in a day. Did you mean it literally that the compressors run constantly? Are they variable units?

I'm sure window units have come a long way but is it even possible that they are more efficient than a central unit?

 

[JHZR2]

ok so word choice on your part and my part were not exact enough I think

you asked if you had to screw into a window and ruin a window? the answer is no
2 tiny screws into the woodwork which imo are optional at least with my window type.
The screws could be replaced with a piece of wood.. or nothing.
the bracket is extremely stable and works excellent even just resting on the outside against my vinyl siding.

There is also a sliding brace that slides out in the u section to the side of the window
so the AC can go nowhere. it requires 2 screws.. to lock it into place these go into the brace and brackets on the ac
not anywhere on the window. but you could just slide them out and it locks the ac into the window.. I dont even use mine. its not going anywhere with the window closed.
and it barely fits in my window(width) so its a pain to get a screwdriver in there but doable.

edit: I added more to post @JHZR2

If you are thinking about replacing regular window ac with these.. they are a winner. I'd buy another tomorrow full price if this one dies... that much better.

Thanks for all the clarifications. And to be double definite - the Midea type, not the GE/saddle style, right?

 

[Rand]

Thanks for all the clarifications. And to be double definite - the Midea type, not the GE/saddle style, right?

I have a Danby
which is an exact clone of Midea u-shape.
12k Midea u-shape is currently 279 at Costco

 

[Rand]

Also, I do believe it's more efficient per watt vs my seer 14 central air
if my central air died ie compressor failure.
I'd probably buy one of those 12K Midea's, at least for the short term until I replaced all my HVAC.

 

[PandaBear]

incorrect. Although you can have many fitment issues for edge cases/odd windows.. it fits fine in most standard type windows.
I have to remove the window handle from the front of the window -2 screws so it will slide into the U shape.
the support bracket gets 2 tiny screws into the wood frame around the window I've had it in and out 20x and same tiny screws work fine.
You could likely wedge these with a couple pieces of wood and not even use screws if you had some type of exotic window ..once the unit is on the bracket and the window closed its not going anywhere.. the expanding front part of the bracket is very stable.. even without screws as The front bracket expands wider than the window opening.
View attachment 274716

Personally I would use threaded insert + machine screw to mount and unmount annually to avoid wood window being damaged. However in your case since it does not have enough room, you probably are better off drilling a hole slightly off the rail to avoid clearance issue.

 

[PandaBear]

Incorrect… but you DO have to screw into your woodwork?!?!??

I’m trying to not screw into anything. My 3-month window units don’t screw in anywhere. Zero damage.

These units are very tempting compared to more mini splits in my home. We don’t use AC much…

Only if you have a flat window sill and not a "lip" window frame. If your window has a bottom "lip" you can literally hang it without screwing in anything.

 

[JHZR2]

Personally I would use threaded insert + machine screw to mount and unmount annually to avoid wood window being damaged. However in your case since it does not have enough room, you probably are better off drilling a hole slightly off the rail to avoid clearance issue.

Threaded insert still destroys the wood in my book. My home has original 100yo American Chestnut trim so I’m hesitant to drill into it, let alone install an insert.

That IS the right way to do it IMO for frequent install and removal. We always remove ours.