I have a 3 1/2 ton aman system and I have had a problem cooling the house when it hot outside.(over 90)'

It cools perfectly fine when the temperature is in the 80's. I checked the evap. Coil and it looks very clean. So is the condenser. The suction line and head reads 74/220. Temp at register is 64 and temp at return is 76.

I had the ducts checked and tey where all sealed properly with no leaks. The repair man said it just the hot heat but I didn't have this issue last year. The home is 1500Sq foot and has about 18inches of insulation in the attic.

I can't figure out what is wrong and neither can the AC techs. I have a newborn and want to get this solved as soon as poosble without having to keep calling technicians out. I had two different ones come out and still having te same issue :(

1500 sf only takes a 2 ton unit you are probably not getting any humidity out of the house. Is this how old is this system? Are the registars in the floor or the celing?

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Originally Posted by Joshdta

1500 sf only takes a 2 ton unit you are probally not getting any humidity out of the house. Is this how old is this system? are the registars in the floor or the celing?

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The are in the ceiling all 8' except living room has vaulted ceilings. The system is the original size the home came with and had never had any problems up to this year. The condenser was changed 3 years ago but the air handler inside is about 9 years old but the coil is clean as a whistle

Sounds like you then have a 13 seer outdoor unit and a 10 seer coil inside, did they make any modifications to the indoor unit when the outdoor was changed?

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Originally Posted by Joshdta

sounds like you then have a 13 seer outdoor unit and a 10 seer coil inside, did they make any modifications to the indoor unit when the outdoor was changed?

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No I don't believe so. But it worked fine up to now! Should I just suck it up and replace the inside air handler?

Today it didn't go below 82 but last night I had to adjust the thermostat because it got too cold(72)

Temp at register is 64 and temp at return is 76

You only have a 12 degree TD and it should be 18 to 20.

Many things can cause this.

If your indoor coil is a 10 SEER and the outside unit is a 13 SEER they should have installed an expansion valve.

If the unit has been opened lately or refrigerant added the system could have noncondensibles. The only way to find that out is to recover the refrigerant from the system and recharge with fresh/pure refrigernat of known quality.

The refrigerant charge can be a challenge on these mixed units. I would check the subcooling AND the superheat and see what category it is falling into. This might tell you if you are over charged/under charged.

There are many more items that could be causeing this but a knowledgeable person would actually have to give it a good look over.

I assume this is a R-22 machine but you never stated the refrigerant type.

Somewhere in your area there is a HVAC person with enough talent to correct your problems. The problem will be to find that person.

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Originally Posted by hvac1000

Temp at register is 64 and temp at return is 76

You only have a 12 degree TD and it should be 18 to 20.

Many things can cause this.

If your indoor coil is a 10 SEER and the outside unit is a 13 SEER they should have installed an expansion valve.

If the unit has been opened lately or refrigerant added the system could have noncondensibles. The only way to find that out is to recover the refrigerant from the system and recharge with fresh/pure refrigernat of known quality.

The refrigerant charge can be a challenge on these mixed units. I would check the subcooling AND the superheat and see wat catagory it is falling into. This might tell you if you are over charged/under charged.

There are many more items that could be causeing this but a knowledgeable person would actually have to give it a good look over.

I assume this is a R-22 machine but you never stated the refrigerant type.

Somewhere in your area there is a HVAC person with enough talent to correct your problems. The problem will be to find that person.

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It is a R-22 unit and the refrigerant was recovered just last week and new one put it. Also it does have an expansion valve and the tech told me it was working fine. He said the suction line would either read nothing or very high if this was the problem.

I have one more tech coming out in the next couple if days. He will be the third hopefully he can fix it.