Single room air conditioner

[Muse]

I'm reading the use and care guide for Frigidaire window AC's. Lots of good tips there on maintenance. One that stands out for me off the bat (I wouldn't have guessed) is the admonition to not turn it back on within 3 minutes of turning it off.

I am making the 20 miles-each-way trip to pick it up first thing in the AM. Even tonight, it's overwarm in my bedroom (I'm ordinarily asleep at this hour).

Where I'm going to install it is actually the perfect place. The window is north-facing, is right over my bed. It will pass air right over the middle of my bed, the controls are on the best side, right where I can easily reach them when in bed. I have a feeling I'm going to like this. I may want to remove it not infrequently, so I'm going to do the installation with that in mind.

I got the 5000 BTU Frigidaire unit from Lowe's. Same one you'll see around that price at other locations and sites. I would highly recommend this unit. It should suit your needs just fine.

In all likelihood in 24 hours I will be enjoying that very unit. I don't know where or how I encountered the code that gave me the 10% discount.

 

[bryanl]

Consider a small swamp cooler. I used one in Miami to cool a small 3 room office with computers when the building A/C crapped out.

I live in an equally hot but much drier climate, and swamp coolers do not work l well above a RH level of 25-30%, making them useless after June. However one mistake many people make with a swamp cooler is not slightly opening a window on the opposite side of the house since outside air is a must for evaporative cooling to work.

 

[Rubycon]

I live in an equally hot but much drier climate, and swamp coolers do not work l well above a RH level of 25-30%, making them useless after June. However one mistake many people make with a swamp cooler is not slightly opening a window on the opposite side of the house since outside air is a must for evaporative cooling to work.

I believe he was being sarcastic as no one in Miami would use a swamp cooler! The wetbulb is way too high 99% of the time!

 

[Muse]

I have my Frigidaire 5000 BTU AC now, have read the instructions, the unit's still in the carton. I'm going to install it (in a quick and dirty way) according to instructions in a few minutes. However, my intention now is to do something DIY with it next week, beyond the ordinary. Got the idea yesterday. I have some plexiglass panels (~ 11.75" x 4') that have been sitting around quite some time, found them somewhere. It's thick, almost 1/4", I think it's actually .236", which is a thickness I saw on a website:

See Plexiglass-Noise-Reduction, where they say that plexiglass is a better soundproofing material than glass. They show test results right on that page.

I will cut a couple of pieces of plexiglass to fit in place instead of the accordion side-panels Frigidaire supplied. For today, I'll use the accordion panels because I want to get something installed for the next few days, we're in a bit of a heatwave. Then I'll remove those panels and cut plexiglass, get it in there somehow in my 35" wide single hung window, do something to make things pretty air tight.

I figure the plexiglass is safer than glass, easier to cut (for me it is), better soundproofing, and it gives the whole window more transparency, the lower part will still have some of the properties of a window. I hope to make the installation such that it's not hard to remove the AC and reinstall. If I want the opaqueness of the panels to get the room real dark I can and probably will fashion a couple of panels (cardboard would work) that I can Velcro in place at will.

I watched a few Youtube videos of window AC's installations today. One very interesting one suggested making and attaching a horizontal diverter between the top vents and the bottom ones on the front. The guy said that this prevents the cold air coming from the top vents from being sucked back into the machine, therefore increasing its efficiency. This is the first I've seen of that idea. Anyone know anything about this? Does air really get sucked into the bottom vents at the front of window AC's? This was the video: National Renewable Energy Laboratory - NREL, Homeowner's Guide to Window Air Conditioner Installation . The diverter application was shown near the end of the ~6 minute video.

Edit: I just pulled it out of the carton. Yeah, obviously it gets its air from inside the room, not outside, where it's probably a lot hotter. The air is sucked into the lower vents, so having a ~4-5 inch diverter would only help the thing not to suck any of the already-cooled air back into the machine! :awe:

 

[alkemyst]

I believe he was being sarcastic as no one in Miami would use a swamp cooler! The wetbulb is way too high 99% of the time!

Most would think a wetbulb here, was not drying off properly after a shower.

 

[MrSquished]

my landlord provided a small window unit for my bedroom so i wouldn't have to use the main big one in the living room that cools the whole apartment when i just wanted the BR cooled(1 BR apt)

which is very nice of him, but however it is fricking loud. anyone here know a small but very quiet window unit? quiet is key. want to pick one up asap.

this is my apt, bedroom that needs to be cooled with this unit is first. it's a decent sized bedroom, that's a queen size bed. the room is 11'x15' so 165 sq feet. definitely want a window unit, nothing portable.

the big unit in this living room can cool the whole place but it's a waste of money when i just want to cool the BR

and for no reason here is the kitchen & bathroom. just cause i like them

 

[shortylickens]

http://www.amazon.com/gp/product/B006YG683C/


Works great. I have been happy with it for 3 months now.

 

[Red Squirrel]

http://www.amazon.com/gp/product/B006YG683C/


Works great. I have been happy with it for 3 months now.

If you want to double it's effectiveness locate the condenser intake (probably the bottom grate on the back) and build a box around it, and add a secondary hose. That will be the air intake, which then gets exhausted outside. This way you're not creating negative pressure and sucking that precious cold air back outside.

 

[Muse]

I'm concerned that my newly acquired Frigidaire FRA052XT7 5,000-BTU Mini Window Air Conditioner gets its air from my bedroom's interior at all times (I'm almost positive). In the evenings, which is going to be the only time I use it for the most part, after going to bed, the room may be, say, 79 F, but outside it might be 58-60 F. It seems to me that a cheap, efficient way to cool the room (less than 100 sq. ft.), would be to suck air from outside into the room. This AC doesn't support that.

If I have the AC running in fan-only mode (high or low), it just sucks interior air in and expels it back into the room. That accomplishes little. If I have the AC running at any but the top setting, the compressor doesn't function (I tried this last night), and the same thing happens (fan-only mode is in effect). If it's on the top setting, well, it's a little chilly soon. So, I'm thinking "why not install fan(s) to suck outside air into the room." So, I have this thought:

I have a box of computer case fans. Many typical size, 80mm, bigger one 92mm, a couple of 120mm. I figure I could remove the accordion side panels of the AC and replace them with Owens Corning 1/2" insulating flat-sheet foam panels (already have), with cutouts for several of these fans, 3 or 4 of them, having them draw air from outside into the room. The window opening is 35", barely less than the maximum of 36" that this AC fits into. There's ~22" extra space, so I could have one or two pieces of foam, totaling 22" with fans attached.

Could I wire these in parallel and have them powered by my Schumacher SE-1-12S-CA Fully Automatic Onboard Battery Charger - 1.5 Amps ???

The noise from a few computer fans doesn't concern me. Some of them are low noise fans. Actually, the more noise the merrier, within limits, I want to kill outside noise with some white noise. However, the sound of the AC's fan system is excessive, on high or low (not much difference)!

 

[Red Squirrel]

Yeah I don't think most small AC units will have economizers (dampers basically). Though, AC is very efficient when the hot side is in low temperatures, so there is that. It will cool the room faster and cooler when it's cooler out.

Usually what I do when the outside temp drops at night is I open the patio door, put a huge fan to suck air in, then open all the windows on the second floor (split level house).

Should be able to power a bunch of computer fans with that charger, just ensure it does not exceed 1.5 amps of load.

 

[Caveman]

Portable ones from home depot work great. I'm using one right now. Cranks out the AC just fine.

I've got a "media closet' where there's a large stero Rx, BD player, and a large PC keeping a 4770 cool... That closet is about 30sqft and has no window so I'd need to dump the water somewhere... Problem is I don't know how much water will need to be dumped during operation... I can install the hose to vent out the floor (which is my garage ceiling) but then I suppose I'll have a bunch of puddles on the floor to clean up. Question is: how much water do those portable units around 10k BTUs produce?

 

[alkemyst]

Depends on the relative humidity they are dealing with.

 

[Muse]

Yeah I don't think most small AC units will have economizers (dampers basically). Though, AC is very efficient when the hot side is in low temperatures, so there is that. It will cool the room faster and cooler when it's cooler out.

Usually what I do when the outside temp drops at night is I open the patio door, put a huge fan to suck air in, then open all the windows on the second floor (split level house).

Should be able to power a bunch of computer fans with that charger, just ensure it does not exceed 1.5 amps of load.

Thank you for this post. Really good idea what you're doing with that big fan and opening the windows upstairs when it cools outside. Super idea! I have a couple of big fans I could potentially use in that way.

A problem that's not really solvable is just that the upstairs of the house has absorbed a lot of heat from the exposure to sunlight in the warm-hot daylight hours and it takes time, a lot of time, for that heat to dissipate. This is why turning on the AC for ~30 minutes will cool the room from ~79 to maybe 67 or less, but a few minutes after turning the AC off, the temperature in the room is back to the mid-70's at least.

Last night I had more thoughts. Maybe I can do something DIY that's a little off beat but effective: Make a couple of screens (or one screen if I have the AC tucked to one side, I'd make it the left side because of where my bed is), and have that screen(s) there when I want outside cool air to waft into the room, which was my former means of cooling the room, day or night. Well, I have on occasion jammed a giant box fan right in that window and turned it on high! :awe: If I don't want air coming through the screen (maybe if actually hotter outside, or winter when I want to keep cold air out), I could either replace the screens with insulation material (the Owens Corning Film-Faced insulating 1/2" foam I mentioned in my last post), or maybe somehow place the insulating material over the screen. I could either have fans attached to the insulation rectangle(s), or have separate rectangles. Jam them in place or tape them in for a semi-permanent system if I'm happy with the way it's working out in the variety of weather conditions here.

Yeah, thanks for confirming my idea about the charger powering the fans. I have a Kill-a-Watt that's helping me evaluate things.

The AC's fan system is pretty loud. I can sleep with it, but when I'm semi awake, the noise does bother me. Maybe I'd get used to it, but I think a few computer case fans would be very tolerable and might provide the right balance of ventilation and white noise for my situation, most nights I need some but not a lot of both.

 

[Muse]

Yeah, thanks for confirming my idea about the charger powering the fans.

Well, I tried hooking up one of the 120mm 12v case fans I have to the Schumacher SE-1-12S-CA Fully Automatic Onboard Battery Charger - 1.5 Amps. It seems to be an iffy proposition. The charger when plugged into wall current doesn't have a DC potential between the + and - alligator clips. Once you hook it up to a car battery, and then remove it from the battery's terminals, it shows 10+ volts potential. It will then run the fan, not before. I suppose it has to do with safety concerns, the alligator clips swinging free when you plug it into 120v A/C wall current.

Maybe there's a way to get the charger to power my array of in-parallel 12v computer case fans, but right now, hooking a fan up to the alligator clips, nothing happens unless I first hook the charger up to my car battery.

 

[BUTCH1]

or just break the glass.

I have misread while working that his room was 700 sq ft not cu ft.

I am looking at a 14k BTU unit for my family room since the previous homeowner added it on and only put in two 4" ducts thinking that made for a larger duct.

I just bought this LG unit last week when my central AC's compressor bit the dust, my county has a law that states that any R-22 based unit cannot be replaced unless it's a matching evap/condensing unit, since my evap coil/air handler is of the '70's vintage that meant an entirely new system for $4K, $5K for the 15 seer rating that gets you the tax credit, ouch. Thoughtless assholes that didn't consider the people who don't make a lot of $$ or or living on a fixed income, kinda tough to come up with that kind of cash. Anyway I like LG because their stuff seems to last but keep in mind when your talking 12K BTU or 14K BTU (both can run in 120V) these are heavy machines, I did install it myself but my back was a little grouchy the next day, my 12K BTU draws 9.8 amps, the 14K LG model draws 12 amps so you will need to use a branch that has nothing else on it. The unit is fairly quiet and I measured the temp at it's outlet at 28 degrees below ambient so that's pretty good, my central never did better than 18 but unless your attic is well ventilated the ductwork is sitting in 125 degree air so you lose a lot of efficiency right there..http://www.homedepot.com/p/LG-Electronics-12-000-BTU-Window-Air-Conditioner-with-Remote-LW1214ER/204683994

 

[T9D]

I've got a "media closet' where there's a large stero Rx, BD player, and a large PC keeping a 4770 cool... That closet is about 30sqft and has no window so I'd need to dump the water somewhere... Problem is I don't know how much water will need to be dumped during operation... I can install the hose to vent out the floor (which is my garage ceiling) but then I suppose I'll have a bunch of puddles on the floor to clean up. Question is: how much water do those portable units around 10k BTUs produce?

They don't have any water. It's made to evaporate the water. I've never once had a drop of water from mine. Although I am in the west coast and its not much humid here. Once in a great while we will though, but never had any water then either. It burns it off and sends it out the exhaust pipe.

 

[T9D]

If you want to double it's effectiveness locate the condenser intake (probably the bottom grate on the back) and build a box around it, and add a secondary hose. That will be the air intake, which then gets exhausted outside. This way you're not creating negative pressure and sucking that precious cold air back outside.

Double huh? That's such bull. I wish ATOT would stop trying to push these do it yourself ad on things all the time. I mean I see where you are trying to go in theory.

But portable units are made to work well the way they are. The problem with the way you do it is that you are now pulling in 100 degree air from outside. Which is going to heat the heck out of your unit. And heat up your whole system and cause more radiant heat. Probably shorting the life too. And be LESS, way less efficient. AC units can only cool the air so much. I think it's like 20 degrees less than the air it takes in or something like that. Or maybe a little more but you get the idea how pulling in heated air can be a problem, especially since it's basically shooting out and then going right back in with the already even hotter air it just shot out.

Sure if you have some giant holes in your house and cracks then yeah you'll pull in to much heated air from all over from the pressure. But throw a towel under the door crack and keep things reasonably sealed and they work super well.

Mine is set up how they say and how it's supposed to be and it works so dang well. I can't imagine it getting any colder. It was 100 degrees yesterday and I had my tank top on, and was actually to cold at times. I laid down and watched TV with blankets on me. I mean I doubt it could possibly get any better than that or more efficient.

 

[Muse]

Maybe there's a way to get the charger to power my array of in-parallel 12v computer case fans, but right now, hooking a fan up to the alligator clips, nothing happens unless I first hook the charger up to my car battery.

I started looking for 12v power supplies, but looking through my box of old wall warts I found one that I think should be fine to power a couple of 120mm computer case fans. Even my one Panaflo 120mm fan seems to push quite a bit of air and the sound may be OK for me. I'll give it a try and if the room doesn't cool enough at night I'll buy another and run them in parallel with the wall wart, but I think one will be OK. Really don't want to leave that AC on all night on any setting. It'll get occasional use.

 

[Red Squirrel]

Double huh? That's such bull. I wish ATOT would stop trying to push these do it yourself ad on things all the time. I mean I see where you are trying to go in theory.

But portable units are made to work well the way they are. The problem with the way you do it is that you are now pulling in 100 degree air from outside. Which is going to heat the heck out of your unit. And heat up your whole system and cause more radiant heat. Probably shorting the life too. And be LESS, way less efficient. AC units can only cool the air so much. I think it's like 20 degrees less than the air it takes in or something like that. Or maybe a little more but you get the idea how pulling in heated air can be a problem, especially since it's basically shooting out and then going right back in with the already even hotter air it just shot out.

Sure if you have some giant holes in your house and cracks then yeah you'll pull in to much heated air from all over from the pressure. But throw a towel under the door crack and keep things reasonably sealed and they work super well.

Mine is set up how they say and how it's supposed to be and it works so dang well. I can't imagine it getting any colder. It was 100 degrees yesterday and I had my tank top on, and was actually to cold at times. I laid down and watched TV with blankets on me. I mean I doubt it could possibly get any better than that or more efficient.

Well, most AC units do use outside air to cool the condenser anyway, essentially I sorta turned my unit into a mini split, in a sense. Yeah there's some radiant heat but the air is moving pretty quick. The exhaust tube has insulation on it as well.

The biggest thing is that I am no longer sucking heat indoors and sucking cool outdoors. When I first bought it it barely changed the room temp as it was just sucking all the air outside. (same idea as those old style wood fireplaces that actually cool the place down more than anything). If you take air and put it outside that air needs to be replaced. It will be replaced with outside air.

With my mod it's a closed system so there is no hot air being sucked in the living space (only inside the unit) and no cool conditioned air being sucked outside.

Since my system is meant to be put away in winter it's not as sealed up as it should be, but I see a HUGE difference. I say double, but it's probably even more efficient than that. I just don't have a way to calculate an exact method other than comparing the time it takes for the room to go down 1 degree.

That said a portable will never be as efficient as a proper mini split or even window unit. Though before my mod, I could never get the temp down to 20 like I can now.

 

[Rubycon]

Well, most AC units do use outside air to cool the condenser anyway, essentially I sorta turned my unit into a mini split, in a sense. Yeah there's some radiant heat but the air is moving pretty quick. The exhaust tube has insulation on it as well.

The biggest thing is that I am no longer sucking heat indoors and sucking cool outdoors. When I first bought it it barely changed the room temp as it was just sucking all the air outside. (same idea as those old style wood fireplaces that actually cool the place down more than anything). If you take air and put it outside that air needs to be replaced. It will be replaced with outside air.

With my mod it's a closed system so there is no hot air being sucked in the living space (only inside the unit) and no cool conditioned air being sucked outside.

Since my system is meant to be put away in winter it's not as sealed up as it should be, but I see a HUGE difference. I say double, but it's probably even more efficient than that. I just don't have a way to calculate an exact method other than comparing the time it takes for the room to go down 1 degree.

That said a portable will never be as efficient as a proper mini split or even window unit. Though before my mod, I could never get the temp down to 20 like I can now.

More like a package unit.

Anyone remember those Koldwave units from the 80s?
They had water cooled condensers, all you needed was a supply of tapwater and a drain and you had powerful, in house (middle room) AC!

 

[alkemyst]

More like a package unit.

Anyone remember those Koldwave units from the 80s?
They had water cooled condensers, all you needed was a supply of tapwater and a drain and you had powerful, in house (middle room) AC!

Koldwave is still a big player.

 

[Imp]

I want to get a Dyson bladeless fan... The thought of having spent $350 on a fan that could be had for $10 -- but omfg, da blades -- should cool me down.

Seriously, I want one.

 

[alkemyst]

I want to get a Dyson bladeless fan... The thought of having spent $350 on a fan that could be had for $10 -- but omfg, da blades -- should cool me down.

Seriously, I want one.

They are cool, no doubt, but inefficient.

I like Vornados if I have to have an area fan. Normally a good ceiling fan is more than adequate.

 

[alkemyst]

Well, most AC units do use outside air to cool the condenser anyway, essentially I sorta turned my unit into a mini split, in a sense. Yeah there's some radiant heat but the air is moving pretty quick. The exhaust tube has insulation on it as well.

The biggest thing is that I am no longer sucking heat indoors and sucking cool outdoors. When I first bought it it barely changed the room temp as it was just sucking all the air outside. (same idea as those old style wood fireplaces that actually cool the place down more than anything). If you take air and put it outside that air needs to be replaced. It will be replaced with outside air.

With my mod it's a closed system so there is no hot air being sucked in the living space (only inside the unit) and no cool conditioned air being sucked outside.

Since my system is meant to be put away in winter it's not as sealed up as it should be, but I see a HUGE difference. I say double, but it's probably even more efficient than that. I just don't have a way to calculate an exact method other than comparing the time it takes for the room to go down 1 degree.

That said a portable will never be as efficient as a proper mini split or even window unit. Though before my mod, I could never get the temp down to 20 like I can now.

It's really about thermodynamics at it's core.

A/C units are designed to deal with ambient temps.

You can't keep on recooling the cooled air though, eventually things break down.

Most window units if sized right can make a room too cold if on max.

 

[alkemyst]

I just bought this LG unit last week when my central AC's compressor bit the dust, my county has a law that states that any R-22 based unit cannot be replaced unless it's a matching evap/condensing unit, since my evap coil/air handler is of the '70's vintage that meant an entirely new system for $4K, $5K for the 15 seer rating that gets you the tax credit, ouch. Thoughtless assholes that didn't consider the people who don't make a lot of $$ or or living on a fixed income, kinda tough to come up with that kind of cash. Anyway I like LG because their stuff seems to last but keep in mind when your talking 12K BTU or 14K BTU (both can run in 120V) these are heavy machines, I did install it myself but my back was a little grouchy the next day, my 12K BTU draws 9.8 amps, the 14K LG model draws 12 amps so you will need to use a branch that has nothing else on it. The unit is fairly quiet and I measured the temp at it's outlet at 28 degrees below ambient so that's pretty good, my central never did better than 18 but unless your attic is well ventilated the ductwork is sitting in 125 degree air so you lose a lot of efficiency right there..http://www.homedepot.com/p/LG-Electronics-12-000-BTU-Window-Air-Conditioner-with-Remote-LW1214ER/204683994

I agree. However, it's important we consider the environment.

I have a friend that sealed his attic (he did some other things too with it all to make it work, but I haven't slept in 30 hours now) and cooled it with his central air. His bills decreased and his house is always comfortable.

My apartment only had a wall mounted A/C...the first one sucked (came with the place) and was really expensive to run once I found that out after I upgraded the unit.

My landlord was awesome. I told him the existing unit failed finally. And he just told me have it fixed and send me the receipt.