Ineffective Thru-Wall AC Units

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Old 08-19-09, 12:15 PM
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Unhappy Ineffective Thru-Wall AC Units

I'm in New York City, and my apartment has thru-the-wall AC units in each room. They are big, expensive and supposedly powerful units (like the ones you see in hotels). When I first bought this place, the units currently in the apartment were shot, and over time I replaced each of them. I now have one Ice Cap, one Island Air and one RetroAire (I wanted to see which was most effective). They are all rated for plenty of BTU's (on paper) for the size of each room. I've also had my windows tinted and have blinds in the windows.

Yet, on these hot summer days, I can't even come close to keeping my apartment comfortably cool. And my electric bills are through the roof. Even if a unit is running all day, the room will still be uncomfortably warm if you stand more than 3 feet away from the unit.

I've spoken to repair people and they all say that nothing is wrong with my units. That it's just not possible to keep my place any cooler. Or they will suggest keeping the blinds closed, etc. Sheesh.

Does anyone have any ideas or advice for me?
Thanks in advance.
 
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Old 08-19-09, 01:54 PM
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Well, just to be clear, it is possible to modify your appartment so that one unit will freeze you out. Having said that and assuming the units are working properly, the solution lies in insulating your appartment. Now appartments have access issues so if you want to change things the work will often be on the inside.

First, what do you have access to and what can you change, insulation related.

Bud
 
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Old 08-19-09, 03:11 PM
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If you put an alcohol thermometer infront of the grill where the coldest of the air blows out - what do they each put out? And what is the outside air temp and inside the apt. temperature?
 
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Old 08-19-09, 03:13 PM
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A few questions.

You haven't said how long you have had these units and if they ever did work.............did they?.
Also, how did the original units work if at all?
If the new a/c units did work when you got them have you taken them out for cleaning?

These units draw air into the outdoor section and blow outward through the condenser............you would not see any dirt build-up unless you pulled them out and looked inside.

What is the total square footage of the apartment and the capacity of each a/c unit?
 
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Old 08-19-09, 03:37 PM
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Arrow You Need a WindMachine 3300 for air circulation!

Originally Posted by Jonny Klobber View Post
I'm in New York City, and my apartment has thru-the-wall AC units in each room. They are big, expensive and supposedly powerful units (like the ones you see in hotels). (Clipped)

Yet, on these hot summer days, I can't even come close to keeping my apartment comfortably cool. And my electric bills are through the roof.

Even if a unit is running all day, the room will still be uncomfortably warm if you stand more than 3 feet away from the unit.

I've spoken to repair people and they all say that nothing is wrong with my units. That it's just not possible to keep my place any cooler. Or they will suggest keeping the blinds closed, etc. Sheesh.
Does anyone have any ideas or advice for me?
Thanks in advance.
Room Units don't have enough air throw to cool an apartment or floor of a home unless you have a WindMachine 3300 20" floor type fan to circulate the cold air & help Return the warm air to the units air intake. Wal-Mart sells them around here.

I cool, perfectly in 104-F Heat Index the 1st floor, 850+sf farm home with a little 3-speed 6,000-BTUH Half-Ton Room A/C with good airflow & a WindMachine 3300 3-spd 20" fan assist.
 
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Old 08-19-09, 04:15 PM
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Originally Posted by HVAC RETIRED View Post
I cool, perfectly in 104-F Heat Index the 1st floor, 850+sf farm home with a little 3-speed 6,000-BTUH Half-Ton Room A/C with good airflow & a WindMachine 3300 3-spd 20" fan assist.
But (out of curiousity) what is the actual temp inside when doing so? And are you sitting right in front of the big fan? Sweat + fan alone can make some people feel pretty nice.
 
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Old 08-19-09, 05:15 PM
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NYC tech here...i have worked on all types of PTAC install problems.questions for you...what are the btu ratings per room of the unit tags(same as neighbors and are they cooling)...are you on the east or west side...are the units flushed up to the grill work if there in cabinets or just standing alone in the room.if your doing 18F from the air entering to the air being sent out of the unit thats all it can do in regards to cooling the room.with the sun not blocked out of the room with the blinds tweeked to keep the sun from hitting anything will help but any sun hitting the floor or walls or furniture adds to the load in the room ,and eats up the BTU rating in that room.if your for example facing west and you come home from work that load with the sun banging your window will take hours to cool of and cycle the unit...you should be in the 8000/10,000/12,000 btu ratings on those units one in each room maybe 2 in the living room.ypu mentioned that guys check these things if they hooked up guages to check the pressures they lost freon on the disconnecting when they were finished the charges are critical to the ounzes from the factory..if your freon is missing so goes the btu rating on the units
 
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Old 08-19-09, 06:44 PM
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Thanks for all the replies, everyone! I will grab a thermometer tomorrow and get some readings for you. The units never worked especially well, but it seems they may be less effective now than they were. The rooms are 12 x 20, 12 x 15 and 10 x 12. And yes, I believe the living room unit is 18,000 BTU and the other two are 12,000.

Sminker - I am on the East side. Not sure I understood all of your questions. The units are in metal encasements.
 
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Old 08-19-09, 06:49 PM
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I guess I should have them cleaned too - I've had them all for at least 4 or 5 years, and none have been cleaned. Not sure I would be able to do that job myself though.
 
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Old 08-19-09, 07:35 PM
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Not the same as an apartment but I grew up an old uninsulated wood framed house full of leaks. This was in Arkansas where it really gets hot in the summer. We installed an 18000 BTU window AC through the living room wall. That AC pretty much cooled a 5 room house. Only problem was to keep the rest of the house comfortable we had to keep the living room at about 65F. I'm finding it hard to believe the 3 ACs aren't working.

Another poster suggested using a fan to supplement the air flow. Our first AC was an old Monkey Ward from the 50's. It was mounted low in the wall, Without a fan aimed at the ceiling you could actually feel the heat layer when you stood up. We learned from that. The new one was mounted as high as we could get it. (Of course the old one was only 5000 BTU so upping it to 18000BTU made a difference to.) Take room temp readings at floor and ceiling.
 
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Old 08-19-09, 07:42 PM
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Your problem is likely just a simple matter of maintenance!

To clean these they would have to be removed and taken to a coin operated car wash.
You would carefully spray the aluminum fins from the back towards the inside.
You do need to be extremely careful to spray at a 90 deg angle to the fins because if you hit them sideways with the spray you will bend them.

Also be careful to not get the motor(s) or electrics wet and as a precaution don't plug them in for at least 24 hrs.

This is likely all that is wrong with them.
 
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Old 08-19-09, 07:59 PM
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I can't imagine getting any of my rooms to 65 degrees on a hot day. I'm guessing my room temp mid-day is going to be around 75-80 degrees. Will take readings tomorrow though.

And Greg - no way for me to do that in Manhattan! Hahaha. I may have to have them professionally cleaned. However, I don't believe they ever worked that well.
 
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Old 08-19-09, 08:33 PM
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what floor are you on could be just a good condenser cleaning to start with...have to get somebody in to slide them out and acid clean either on site or removed to company shop.find out from the maint.guy there is there a area that the units get washed down...how are your neighbors rooms doing and find out who does their maint.if your not up there,and off a major avenue you won't belive the way a condenser looks after just one season.i have service air cooled commercial equipment 2 to 4 stories up and the condenser were matted like a carpet from filtering 2nd Ave ...Madison Ave traffic.companies that servcie these units Hamilton Air,Donnally Mech,PAR,BP,AFGO call up and tell them you need PTAC units removed and cleaned and checked out...all this if you can't wash them on site.
 
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Old 08-19-09, 09:32 PM
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Thanks very much. I'm on the 20th floor. Will check into having them cleaned. I know other people in the building have had lots of issues with their units as well.
 
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Old 08-20-09, 02:24 AM
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Since you own this unit, some thermal upgrades would be well worth the investment. As stated, all three ac units haven't failed. They may improve some with cleaning, but 10 or 15 % is not going to make a huge difference. Adding an extra insulating layer to the inside of the exterior walls and air sealing will make a difference. Unfortunately I can't point you directly to the problem areas as your building will be unique, but any energy auditor with an infrared camera will find those hoe spots in a blink.

How does your unit do in the winter, any drafts or cold areas?

Bud
 
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Old 08-20-09, 06:55 AM
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Originally Posted by sminker View Post
.if your doing 18F from the air entering to the air being sent out of the unit thats all it can do in regards to cooling the room.
Are you certain this rule of thumb apply to wall or window units (compared to central air)? If so, I am going to have to go back and reassess what I thought I assessed. How come on 80-92 out days, and 80 or more in and about the a/c unit itself, inside the residence, I have found temps taken at the output vent to be 50 degrees or less. ??? I even tested one in a garage one day, when trying to determine if it was good, and it was quite warm in the garage, and when I took the output temp it was about 50, from what I recall.

I have found some window units to be about as low as 43F! (I do seriously believe that when I got that kind of super low reading, it was not just 61F (43 + 18) by the unit, inside or outside).And that is not with an IR temp taken pointed at the cooling coils. Instead, it is actual alcohol temp test taken on outside of the output vent.
 
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Old 08-20-09, 10:10 AM
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Interesting, Bud. The windows aren't super tightly sealed and there is some draftiness in winter, yes. Adding a layer of insulation to the walls sounds like an enormous job. But sealing the windows better sounds like it might be a good option.
 
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Old 08-20-09, 12:08 PM
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Actually, since you would only be doing exterior walls it isn't that bad, of course I'm a carpenter et al. But I've added 2" of rigid foam, extended the electrical boxes and window frames and then added a layer of sheetrock. Alternatively, you can picture frame anything you don't want or can't extend and finish your sheetrock to that. The extra depth also works well for fabricating some inside storm windows. An infrared camera would tell you if there were any floor or ceiling issues.

Since infrared camera prices have come down, you might find a place to rent one, NY is NY. Then possible get several neighbors to chip in on one rental.

Owning your unit means any improvements, especially energy, add to the value of your property. Plus you save summer and winter. There may also be some tax/stimulus incentives to help pay for the improvements.

Bud
 
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Old 08-20-09, 12:37 PM
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Lots of exterior walls here.... With decorative paint, etc.... It would be a major job indeed. You're absolutely right that it would be a big improvement though. I just don't think I can consider something that drastic just yet... There are LOTS of windows, which are drafty. Maybe I could look into having them sealed somehow?

OK... I took a thermometer and did some readings. The temperature outside at the time of the readings was 88 degrees. Room temp in the living room is 80 and the air coming right out of the grill is 60. In the office/2nd br, the temp is 79 and the air coming out of the AC grill is 58.

What do these numbers tell you?
 
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Old 08-20-09, 04:22 PM
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I am going to do more data collecting, myself - and I will give the results. Today is no good since only 64F (unseasonably cool), after here it was pretty hot recently.

The principle basically is the same as central air in the fact you pass incoming air across the evaporator coils, which are really cold, and it yields a compromised temperature out the vent (quite cool, but not near as cold as the coils). I think why window or wall units put out colder than central(from what I have observed, anyway) is the fact that the evaporator coil is so close to the vent, for one thing.

I remember a couple years ago at my neighbors, when their central air was down, they had a window a/c unit going, and I got 46 degrees out of it. I remember that because frankly I was very surprised at that number, per the very thing Sminker said. [And the thermometer was accurate, as I had/have 2 of them (alcohol) and they are within 1 degree of each other.] Now, it it were even 70 that day, in or outside, they would not have even had it on! I have a feeling it was like 80-something out, and about 76 or so in their place, at the time we ran it.

To answer your last question specifically though - you can look at it this way: There is a chance the units are running fine. But even if they are not quite as cold as numbers I have experienced, your numbers rival that of excellent central air. That being said -if your total btus are adequate for the spaces they are in, then that means what others are talking about that you must have heat intrusion to your place that must be remedied.
 

Last edited by ecman51; 08-20-09 at 04:30 PM. Reason: added last paragraph
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Old 08-20-09, 04:42 PM
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1 ton in the bedroom and 1.5 ton in the LR those splits are good even 18F would be OK...is the air being discharged out into the room can you flip the grill on top so it doesn't go up straight....loads of windows the sun might be eating up the btus....how's it during the night?
 
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Old 08-20-09, 04:46 PM
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I'm not sure I understand what you mean with "tons" and "splits," etc. Can you explain in more layman's terms?
 
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Old 08-20-09, 07:48 PM
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Arrow It Cools the Entire Area of 3 rooms (LR,DR,K) & a Hallway

Originally Posted by ecman51` View Post
But (out of curiousity) what is the actual temp inside when doing so? And are you sitting right in front of the big fan? Sweat + fan alone can make some people feel pretty nice.
That is true, but NOT the Case here.

Sorry I don't check in here often, nor receive any E-Mail notice.

In our hottest weather 104-F Heat Index, it got the temp done to 75 or 76-F & 55% RH, & the air is moving throughout the entire floor, I was cool & comfortable anywhere on the 1st floor.

It cools just like a central system. You'd have to set right in front of the fan were it not for the great performing room A/C, & then you wouldn't be comfortable!

The A/C has Omni-Flo elliptical disk that can deliver airflow in any direction.

I angle it toward the blower fan & it sends the cool-air in a circle through all the rooms & back to the Return-Air intake.

It works like a charm & this is a 1937 farm home loaded with windows, too much infiltration air, it is not well weatherized, which I need to do to save on the high Oil heating costs.
 
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Old 08-20-09, 08:34 PM
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This Wind Machine must be quite a fan... I've tried circulating air - I got a Vornado fan a few years ago to attempt just what you are suggesting, but the effect was not very satisfying. Could it be that the Wind Machine is that much more effective?
 
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Old 08-21-09, 05:45 AM
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Originally Posted by Jonny Klobber View Post
This Wind Machine must be quite a fan... I've tried circulating air - I got a Vornado fan a few years ago to attempt just what you are suggesting, but the effect was not very satisfying. Could it be that the Wind Machine is that much more effective?
The 20" 3300 has 3-speeds & is adjustable vertically.

My Whirlpool Half-Ton, Model ACQ062MPO bought in July 2004, also has great airflow.

Many small room A/C's don't have enough airflow!
 
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Old 08-21-09, 06:56 AM
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I find myself fascinated by this thread and coming up with wild ideas on what to try if cleaning doesn't work. First is a redneck idea from my area that I know helps with window mounted ACs. If the units are under windows tape aluminum foil to the glass. Looks tacky but reduces heat load from sun shining in.

The next would be costlier and might do no good but I'd try it. On the AC side of the living
room I would put a through-the-wall vent fan pulling air to the next room and a second through-the-wall vent fan pulling air to the third room with AC. In the third room on the wall opposite the wall with ACs I put third through-the-wall vent fan pushing it back to the second room and finally a fourth fan from that room blowing it back in to the living room on the far opposite side from that AC.

Envision circular rotation from the AC side of the apartment to the far side of the rooms. You'd get the cooling power of all the ACs mixed together and moved to the far side of the rooms. Because cold air sinks I would put the through-the-wall vent fan high in the wall. I would also consider ceiling fans. to help move the air. Of course I'm no HVAC man and they may think my idea is crazy but there it is.
 
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Old 08-21-09, 07:24 AM
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Originally Posted by ray2047 View Post
I find myself fascinated by this thread and coming up with wild ideas on what to try if cleaning doesn't work. First is a redneck idea from my area that I know helps with window mounted ACs. If the units are under windows tape aluminum foil to the glass. Looks tacky but reduces heat load from sun shining in.

The next would be costlier and might do no good but I'd try it. On the AC side of the living
room I would put a through-the-wall vent fan pulling air to the next room and a second through-the-wall vent fan pulling air to the third room with AC. In the third room on the wall opposite the wall with ACs I put third through-the-wall vent fan pushing it back to the second room and finally a fourth fan from that room blowing it back in to the living room on the far opposite side from that AC.

Envision circular rotation from the AC side of the apartment to the far side of the rooms. You'd get the cooling power of all the ACs mixed together and moved to the far side of the rooms. Because cold air sinks I would put the through-the-wall vent fan high in the wall. I would also consider ceiling fans. to help move the air. Of course I'm no HVAC man and they may think my idea is crazy but there it is.

Ray, the foil really works. I have done it. Huge difference you can feel with your hand waving just inside the window(or with a thermometer), compared to when it was not foiled, or compared to nearby window that is not foiled!

Ideas by non-pros are often not crazy. It is called "thinking outside the box". And some of the best and cleverest ideas I have seen have come from non-pro thinkers.

I can't wait for the weekend thru Tuesday, as weather is to get sunny and 80, then onto 83, according to the 5-day forecast. Then I can test my window a/c and maybe test others. I will also leave my windows closed up to intentionlly let it get warm in the place.

Another reason why the 18F differential does not always apply(from my observations at least) is it wlil be influenced as to what the incoming temp is that is passing over the coils. The colder the air passing over the coils, the less differential. Heat transfer is not as great, the closer you get toward equalization. For example, on this one condo, I first tested the central air as is, at the cold air return and at the register. It was like 75 at the cold air return and 63 at the register. Then I opened up the basement blower and was sucking in cold basement air and thermometer test at filter I placed at blower door said 68-70, yet instead of dropping the output register temp down say into the mid-50'sF, it was 61, only!!

Yes, threads like this are fascinating.
 
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Old 08-21-09, 03:20 PM
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Jonny,

You are getting some interesting stories and very wide array of good advice from people with diverse backgrounds.
I am not sure however that you asked about rebuilding your apartment.

I have a few suggestions that may help.
First, you offered the room sizes which total 540 sq feet.
In rough terms the a/c capacity you have is close to three times what this space requires so you must not have given the measurements of the entire space.
We need to know the total size of the apartment to be able to form an opinion as to whether you have enough cooling capacity.

Secondly, if you use a fan, it is to move the warm air towards the a/c so the heat can be removed, not the other way around.
Fans will only help if the a/c has the capacity to over cool the room that it is in.

A solution is very simple.
The main thing you need to know to answer your original question is if your units are working to maximum capacity.
Considering the cost of replacing the units I would suggest that you carefully choose a service company.
Did the company that declared the units to be working properly remove and inspect them?
I recommend that you find a company that is competent, preferably a company that is experienced in larger commercial systems to remove, clean and service them.
Any less is idle speculation.
 
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Old 08-22-09, 12:02 AM
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Hahaha. Yeah, I'm not ready for the major insulation job (though it is probably a good idea down the road).

The entire apartment is in the vicinity of 1100 sq. ft, including hallways, kitchen, bathrooms, etc.

And that is interesting about the fan. My logic was that by putting the fan near the AC unit it would blow the cool air around the room. Perhaps I'll pull the Vornado out of the closet and try putting it on the other side of the room and aim towards the AC unit. I wonder how much of a difference that will make - thanks for the tip though!

I was able to get a look at the condensers on two of the units this afternoon - two of them are located in positions that allow access via balconies. So I removed the outer grill and took a look. Very little in terms of stuff blocking/matting over the fins of the condenser. So I doubt that dirty condensers are to blame here.
 
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Old 08-22-09, 05:03 AM
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the BTU rating on the unit tag is the amount of heat it can remove from the room 12,000 btus equals 1 ton of air conditioing...18,000btus is 1.5 tons.i did start-ups on Trumps condo complex behind Lincoln Center and most of the rooms were 9000,12000 btus per room.so your typical on the ratings.that split thing i mentioned is the evaporator cooling side and the condenser side taking readings on the air in and the air out.....18F drop inside/10F rise outside.question to you is it wood floors in the place and are the returns clear and open no couchs slammed against them noting on top off the grills and the squirrel cages within the FC units clean of dust?
 
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Old 08-22-09, 10:41 AM
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I have some of that info I promised:

On my 8000 btu window unit, I forgot that I had writing on it from 4-29-07. It said that it put out 50F when it was 80 and sun. I think I had meant 80 inside, and sun out.

The next notation was from 6-19-08. It said that when it was 78 inside and 76 outside, the a/c was putting out 46F.

Just a bit ago, when it was 76.6 inside and 66 out, the a/c was putting out 44F! I believe that all the air from the a/c is drawn from the inside. I went outside to all the outside a/c vents and they were exhausting. My a/c does not have any feature on it where it says anything like 'vent control' (open or closed) on it.

BTW, the fan speed was on high, for all tests.

Today is only suppose to be 71. I left the windows closed on purpose to let it get hotter inside so I can do another test later. Then tomorrow and for next few days, temps will get to 80-83, and I will do more tests and leave windows closed on purpose, while I am away for the day. And then I will post my new figures.
 
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Old 08-22-09, 10:35 PM
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Floors here are parquet. There are area rugs covering about 60-70% of the floor space. All grills are free of any obstruction. The one in the bedroom does have the bed up against it, but the grill is not blocked and in the other two rooms, nothing is blocking the units on any side.

Not sure what the squirrel cages are... Should there be squirrels in there? That would explain a few things...
 
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Old 08-23-09, 10:56 AM
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Ya, squirrels. Ha,ha. Anyway there probably is a 'blower wheel' closest to the front, that pulls warm room air through the filter and cold evaporator coil. And connected to it at the rear will likely be a regular bladed fan that does the exhausting thru the hot condensor coils. By spinning any one of these by hand should tell you if the motor bearings are low on lubricant or otherwise shot.
 
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Old 08-23-09, 11:25 AM
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Continuation of data per post #31

Last evening at 6:40 pm -71F out, 85.5F in (no typo - sun beating down all day, windows kept closed, shades open, on purpose, as promised, to intentionally cause hot living area), 50F cold discharge. Not bad for that type of inside temp.!

Then later it dawned on me that I really need to be telling you what the cold air return temp is (located under the cold air grill). So later that evening after dark, a ran the a/c again and it was 76.6F in the room, 55F outside, the output was 42F!!!, and the return air temp was 72. This shows a 30F split(differential between room air input and cold output temps)!!

I do believe also that what I am going to show, as the weather warms over the next couplde days, is how the outside temp also will play a roll in how well the hot coils can disipate heat to the outside. I have a hunch that my 'split' will not be quite as good when the outside temp (out there by the hot coils), goes up substantially.
 
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Old 08-23-09, 12:43 PM
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Some ACs have a knob to allow you to take in out side air. Taking in outside air will reduce the cooling ability of your AC to cool in most circumstances. When I did apartments I had so much trouble with tenants complaining the AC wasn't working only to find it open that I started disconnecting it. I know you have probably already checked but be sure the flapper for outside air is closed if you have one.
 
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Old 08-23-09, 01:26 PM
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Good point, Ray - in fact one of the units did have that switch and it was set to outside air. That has been flipped. The other two don't seem to have any such switch.

I guess I will have to open the front of the units to look inside to see if I can find these wheels and fans. Will check on that tomorrow I think. Thanks.
 
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Old 08-23-09, 04:43 PM
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Originally Posted by Jonny Klobber View Post
Hahaha. Yeah, I'm not ready for the major insulation job (though it is probably a good idea down the road).

The entire apartment is in the vicinity of 1100 sq. ft, including hallways, kitchen, bathrooms, etc.

And that is interesting about the fan. My logic was that by putting the fan near the AC unit it would blow the cool air around the room. Perhaps I'll pull the Vornado out of the closet and try putting it on the other side of the room and aim towards the AC unit. I wonder how much of a difference that will make - thanks for the tip though!

I was able to get a look at the condensers on two of the units this afternoon - two of them are located in positions that allow access via balconies. So I removed the outer grill and took a look. Very little in terms of stuff blocking/matting over the fins of the condenser. So I doubt that dirty condensers are to blame here.
One thing to check regarding the condition of the condensing coil, is the direction of airflow. With the unit running, is the hot air being discharged out the back of the coil or through the grills on the side/top of the unit. If it is discharging through the back of the coil, the coils could be matted, partially plugged on the inside as that is the direction of air flow.
 
  #38  
Old 08-23-09, 10:45 PM
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Originally Posted by johnsonr1 View Post
One thing to check regarding the condition of the condensing coil, is the direction of airflow. With the unit running, is the hot air being discharged out the back of the coil or through the grills on the side/top of the unit. If it is discharging through the back of the coil, the coils could be matted, partially plugged on the inside as that is the direction of air flow.
I'll see if I can remove the front panel on each unit tomorrow to see if I can do this. Thanks!
 
  #39  
Old 08-24-09, 07:08 AM
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Contination of data from posts 31 and 34

Last evening at 6:50PM I had 89.8F inside and 74.5 outside, sun. 84 being sucked into the 8000btu window a/c at it's cold air return and a 54F cold discharge into the room. Again, a 30F split. This may helkp everyone with window or wall units get some handle on what you might expect your a/c to produce.

The one-ton wall unit I worked on I remember that too put out real powerful cold air also.

...................................................................

If window and wall a/c's give off so much more, in the way of the split temp readings, you'd almost have to think that per btu, these would be more economical to run than central air, where the split is only a measely 16 -20F between cold air return and output temps. But somethign tells me that when it comes to energy, that there are no free lunches, and there must be some reason why window and wall units generate a bigger split temp. Maybe as much as these apparently blast out cold air, that they are actually not taking in enough circulatory air and this causes more of the coil temp itself to come out?

Also, they probably design central air the way they do so that more regsiters distribute a more tolerable temp as to not chilll any given small area, but to cause temps to be more uniform throughout.

I know a place that has like 3 window a'/c's going, and another place like it that has central air - and it be fun to compare energy useage. The hard part is I do not own these places. Therefore, my only hope is to be able to catch both places running theres steady, over a long enough time period, to monitor their electric meter. However, that still is not comparing apples since the one place may be more energy efficient and/or one places uses more electric for other reasons than the other place.

It looks like I am sort of strapped to simply go by some explanation on the theory -or -if anyone out there actually does know if multiple window or wall units can be more energy efficient than a central a/c(in their stead) that have to run and run and run (the compressor....fan and blower too))to maintain or lower temps.
 
  #40  
Old 08-24-09, 08:59 AM
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Originally Posted by Jonny Klobber View Post
I'll see if I can remove the front panel on each unit tomorrow to see if I can do this. Thanks!
Johnny,

You do not need to remove the front panels to check this (the rear condensing area of the unit will be blocked from the front area by panels and or sheetmetal), as you stated in an earlier post, you are able to see the rear coils of 2 of the units from a balcony. From that vantage point, you can just place your hand near the back of the unit to see if the air is being discharged that way or it is being drawn into the coil and discharged out the side or top of the cabinet. If it is in fact discharging out the back through the coils you will have to have the units removed to clean the condensing coils unless there are access panels to provide access to this area, then you may be able to use a hose to rinse them down, but only after disconnecting the power.

If you post the exact model numbers, I am sure either myself, or someone could post the compete service manual which would have detailed cleaning instructions for your use.
 
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