My wife works in a building where the air conditioner is not cooling. Last year, several serivce people came out and tinkered with it. The unit is upstairs in an attic which isn't cooled. It leaks down into the bottom floor and runs constatnly. It never reaches the temp set at the thermostat. They blew out the drain lines and checked the freon. When you put your hand up to the registers, it blows soft, almost warm air. It isn't cold at all. Parts of the building get cold and others are warm.
I thought about restricting the registers in the middle of the building with adjustable ones and forcing the air to the perimeter by the glass windows to try and combat the heat entering by these windows. Could this help??
Thank you in advance for any help you can offer.

I would not advise you to make changes in a building where your wife works. The building owner is the only one who can make decisions and you could be held liable if something gets messed up. She should be complaining to her boss instead of to you.

Thank you for the advice, but her boss IS the one who asked me to help with this matter, my wife didn't.

I do not want to sound impolite or rude but do you feel more qualified at HVAC repair than the service people who already came out? Could be that your wife's boss is looking for a freebie or cheap and apparently is willing to get what he pays for.

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Originally Posted by ballengerb1

I do not want to sound impolite or rude but do you feel more qualified at HVAC repair than the service people who already came out? Could be that your wife's boss is looking for a freebie or cheap and apparently is willing to get what he pays for.

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Nice of you to consider that. If you must know, I help her out with things at no charge because she is also a good friend of mine. And no, I don't feel I am qualified to fix the problem myself. Apparently neither are the 4 different licensed HVAC service professionals who came out because all they seem to want to do is bill her for a freon check, a filter change, and an hours worth of labor. This is the very reason I have been asked to look at it because she feels she is being taken advantage of due to the fact she is female. They all shrug their shoulders and wait for a 100 dollar check with out taking care of the problem.
Now that you have all the facts and if you have any ideas that will repair the problem, please let me know. Otherwise, please don't respond to the question. I'm not an idiot and I can think for myself. I don't need any liability or personal advice on this matter. Give me a little credit and respect my intelligence before you start making these type of comments.
If you have any suggestions regarding the problem, I would love to hear them. If not, just leave me alone. I asked for help with the HVAC problem not life lessons. Thank you for your time.

There are missing bits of information. First the leak... a water leak? Is coil freezing up? Three causes, non-condensables, low air flow or low on refrigerant.

Are all the offices on 1 unit? If the unit is freezing up due to low airflow, dampering registers to balance the airflow probably just compounded the problem. Let us know what else we could be misssing.

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Originally Posted by NorthernHeat

There are missing bits of information. First the leak...a water leak? is coil freezing up? Three causes, non-condensables, low air flow or low on refrigerant.

Are all the offices on 1 unit? If the unit is freezing up due to low airflow, dampering registers to balance the airflow probably just compounded the problem. Let us know what else we could be misssing.

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Thank you for your response. It is about a 3000 square foot building with two units. Both of the units are located in a finished, but non cooled attic and one of the units is in it's own small service room. I haven't restricted the registers yet. I can not find any signs of it freezing up anywhere. No ice build up on the condensing unit outside, etc. I know this isn't the only sign of one freezing up. They added a unit to the first one a few years ago and it is cooling fine. Both of the units are basically cooling the same open area. I am wondering if there might be a blockage or break in the sheet metal venting somewhere. When I put my hand up to the registers, there isn't much air flow and it isn't cold. When I check the return air, there is good air flow which has me puzzled all though this isn't my profession. Is it possible the freon they add leaks out in a mater of just days and it is freezing up? The drain pipe for the water has about 10 connections in it within a 5 foot span. It may just be leaking due to poor construction. The filters are changed every month. The owner does not know if they have cleaned the coils during the year she has owned the business.
Thank you again for any help you can offer. I really appreciate it.

Yes the freon can leak out in just a few days, if so, this should be an easy leak to find. The duct work is probably insulated inside, at least most commercial work we do is. The insulation could come loose and obstruct just her supply run. Is her run the first one of the plenum or further down the trunk?

For me to give you any more information about the refrigerant charge I would need the head and suction pressures, indoor and outdoor temperatures, liquid and suction line temperatures and if there is and filter/drier installed.

Check temperpature of the air coming out of the vents to see if the unit is actually working right.

It should be anywhere between 54-60 degrees to be working up to standards.

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Originally Posted by NorthernHeat

I haven't forgot you. I still don't have a good answer. I'm sure you've purged the system with nitrogen and checked the piston of the condensing unit for restrictions.

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Thank you for following up with me. After 4 HVAC service calls, we finally got a real professional to take a look at the system and he found several air return problems and we are in the process of correcting them. I will definitely let you know the outcome as soon as we complete the return air leaks. It appears the unit was pulling air from several gaps above the drop ceiling. Plus the outside unit had been boxed in with 6 foot fencing. I will let you know the final answer. Thank you again for helping me. I really appreciate it and I may be back for more good advice...