Need Urgent Help!-air conditioning.

[krusty2515]

Hello everybody.

As you all know, summer is hear and it is getting hot. The problem is that my air conditioning unit never properly works. Here are the list of problems

Air Flow is weak
Air is not cool.
Freon constantly leaks out.


The ac who comes to my house is very lazy and all he does is put some more freon in and says he has patched up the problem. The sad thing is that it has leaked over 11 times in the past 4 years. Every time he comes he insists that he has solved the problem.


I decided to go to another AC guy. He said that the unit was too weak to supply the part of the house that it is hooked up to, The side of the house that has the ac problems is 2000 square ft with 8 ft high ceilings. The price he said did not seem reasonable.

The other guy said that the duct work was not right, but the unit was fine and strong enough. I asked him about the freon leak and he said that is only a very minor problem, whearas i read that it is a pretty big problem. Not trusting this guy I called another guy.


The other guy said that the duct work was fine and that it is an insulation problem that was causing all my problems. He said that the flow was fine. I did not believe him because on the other side of the house it is much cooler and the flow is much stronger, BUT that side of the house is hooked up to a different unit.

Now i am super confused. It is hot as hell and in the afternoons i feel like killing myslef. I live in the southeast united states right along the coastal region, so temperatures reach about 100 F easy because of the humidity.

I emailed an ac guy who i found on the internet who hands out advice and he said i need a 4 ton unit for my house. Not knowing how many tons my current ac system is, i went out side to check. Sadly there is a bunch of information that I do not understand. I took a picture of the information to see if anybody knows what any of it means and if they could help me.





That is a picture of what my AC unit says on the outside.


If anybody could help me i would be extremely grateful. I feel miserable in my house in the afternoons. Plus with all these people telling a bunch of different things, I have no clue who to believe.

[the dangling wrangler]

How can he "know" what you need over the INTERNET? He can't. I can tell you this over the 'net, you have a 3 ton unit. Also, pricing in posts is frowned on here.

[krusty2515]

hey thank you so much for the quick reply. I was just posting how much the guy was charging to show my frustration. Just out of curiosity, did you get 3000 from the 300 psig it says on there? Also he said that was just a very rough estimate. He said i would need a manual J to see how much i really need.

[the dangling wrangler]

036jas. Edit out the price or the mods will.

[krusty2515]

doing some rough calculations, i found out that indeed it came out to around 4 tons i need. But I am going to get someone to check this professionaly. Anyway, does it really matter if the unit is slightly more powerful than what is needed?

[HeyBob]

Moving to residential forum where it belongs!

[beenthere]

Yes, over sizing can cause more trouble then you already have.

[krusty2515]

So is there some general chart that ac guys follow for how many tons you need per square foot of house you need. All i need is a very general chart. That way i can make sure the ac guy cannot rip me off.

[Refer-Madness]

So is there some general chart that ac guys follow for how many tons you need per square foot of house you need. All i need is a very general chart. That way i can make sure the ac guy cannot rip me off.

Look back up at your post, post #3, and you've answered your own question. Manual J

[krusty2515]

The problem is that i have no idea what a Manual J is. I tried searching google, but no results came up that i was looking for. Can anybody explain what that is, or send a link. I am a complete novice at this stuff, so please exuse my ignorance.

[the dangling wrangler]

The problem is that i have no idea what a Manual J is. I tried searching google, but no results came up that i was looking for. Can anybody explain what that is, or send a link. I am a complete novice at this stuff, so please exuse my ignorance.

Look at the top of the page for HVAC calc. Your questions will be answered.

[Refer-Madness]

It is a book for residential load calculations. 1st hit on google when I entered it. You can also look at the top of this page for a link to HVAC calc. there is a homeowners special for doing a load calc on your own home, but its not free and I've never used that software so I cant really tell you anything about it.

[m kilgore]

The only way to properly size your house is with a manual J calculation. This takes into account all of your windows, doors, insulation, room sizes etc. If you want to do one yourself there is a hvac-calc link at the top of this page. There is a cost for this for a one time user.

Any reputable contractor will run the calc. Your having problems and this would take out the guesswork. Going by square footage is just a guess. Call some contractors and ask them if they will run a manual J.

You have a 3 ton unit now and if you need a 4 ton then the ductwork willl need to be altered for the increased capacity.

Post your location and there may be someone on here that is in your area and would be willing to give you some help.

[krusty2515]

i live on the gulfcoast, mississippi.


But why do you guys think that the airflow is weak? Could it have to do something with the coils and the freon always leaking out?

[model m-man]

I think it was you that thought the airflow was weak. LOL It may be, but it may be that the other unit is too strong.

It could be that your coil is dirty or the blower is on the wrong speed resulting in poor airflow. Either will show a low charge if you are going by the pressure guage only. It could be duct leakage, duct liner loose, wrong size duct's, return too small, duct's need balancing. Dirty filter, 3M filter. Lots of possibilities. You need a thorough evaluation of what you have now and what you need to do about it.

Gassing up a unit that often is pretty ridiclous. JMO Did he even look for the leak?

[tinknocker service tech]

the unit was made in 91 and has a history of problems that havent been fixed. You have been leaking refrigerant for a few years no and to some extent the posibility or loosing oil is there also. The guy you have been useing hasnt shown any requard for your well being by being lazy and not finding and fixing your leak.

as far as airflo feeling it doesnt say much and you are not happy with the proformance of this system at all from the way you talk.

I recomend you get prices and load calc this way you can have installed what you need

[mrs reb77]

The sad thing is that it has leaked over 11 times in the past 4 years. Every time he comes he insists that he has solved the problem.

4 years of this fellow putting refrigerant in your system and now you think there is a 'different' problem.

Sounds as if you have an unresolved refrigerant leak (for one) or a totally over charged system (for another). No one can solve your issues over the internet or telephone. You are having difficulties figuring out a Manual J because it isn't something just 'anybody' can do. Please, talk to neighbors, friends, family and find an HVAC contractor they trust to service your system. In 4+ years I would have thought you would have already gone there....

[krusty2515]

well i did not live in my house during much of those 4 years because of hurricane katrina. I had to relocate and just moved back in last year.


I have had many through evaluations but sadly every guy gives different things and they are all charging different prices for fixing different things. One guy will say the ducts are ok, and the other guy will say that the ducts are too small. And I have no idea who to believe.


Also in the day, i notice that hot air is coming out of the vents when the ac is not on. Is that normal, or does that indicate a problem?

[the dangling wrangler]

Also in the day, i notice that hot air is coming out of the vents when the ac is not on. Is that normal, or does that indicate a problem?

Correct. That would indicate a problem.

[udarrell]

well i did not live in my house during much of those 4 years because of hurricane katrina. I had to relocate and just moved back in last year.

I have had many through evaluations but sadly every guy gives different things and they are all charging different prices for fixing different things. One guy will say the ducts are ok, and the other guy will say that the ducts are too small. And I have no idea who to believe.

Also in the day, i notice that hot air is coming out of the vents when the ac is not on. Is that normal, or does that indicate a problem?

Get an accurate manual J done.
A thorough evaluation of the duct system has to be done with all the required remedies done.

If you have high humidity problems, - DO NOT oversize the equipment.
When working optimally, the existing 3-Ton might handle the latent & sensible heatloads.

If you really want to know how well your unit is performing!
Just Click on QUOTE, & fill in all the test data you can.

AC TROUBLE SHOOTING DATA
Age of unit, Tonnage & SEER &/or EER Rating
Square Footage of home| state & major city near you __

“ALL TEMPS in FAHRENHEIT -F”

Outdoor condenser’s DB discharge-air-temperature __
Out-Door temperature: __
Condenser air split __

Records of TECH's Test Data:
Indoor blower Total static-ESP/ accurate airflow in CFM: _

Suction line pres. ___
Suction-Vapor line temperature: ___
SST - Gage - Suction Saturated Temperature. ___
Superheat __

Head pres. __
SCT - Gage - Saturated Condensing Temp __
LLT - Liquid line temperature: __
Subcooling: __

With the information data below and an accurate CFM airflow + sea-level height, I can ball-park its BTUH output
Return Air temp DB &, WB or %RH: __
Supply Air temp DB &, WB or %RH: __

Except for the pressures & CFM, you could take most of the readings.

My advice: get a low cost humidity gage at a local hardware store & see what the percentage-RH is in your home, I can cross-reference that to the wet bulb depression.