AboutHoward Livingston Expertise Can answer questions on electrical control circuits, power supply,airflow & distribution, electrical components,refrigerant problems,gas, electric & propane furnaces.No boiler or refrigerator or oil fired furnaces experience.Just HVAC questions please.
Experience 35 years experience in residential & light commercial repair & installation.
Question QUESTION: Thanks for your help!! We have a Coleman blend air system - 4 ton in a 1782 sq ft mobile home built in 1996. Over the years the A/C has not cooled the house quite as good as the previous year. Yesterday it was 86/87 in the house but coming out of the vents at 69/70. We had someone check the unit twice in the past month and they cannot find anything wrong with the a/c itself, they say it is doing all it can. We live in GA. If you stand in the living room (largest room) and reach toward the ceiling you can feel the heat coming off the ceiling. Last year we had to have a large window unit in the living room, a small one in the kitchen and the central unit running to keep the house cool - the electric bill was over 400.00 a month. I just looked up a manual online and it says some blend air units have a fan in the ceiling. If mine does i dont know where or where to look for it and that would make sense to me if the fan quit that the ceiling would be so hot. Any ideas on anything?
ANSWER: That phrase "it's doing all it can" is familiar. I've used it myself so I would accept that it is full of freon & everything running. The 70 deg air is good. So I would turn to air distribution as the problem. Double wide homes have a duct crossover to distribute air to 1/2 of the house.Usuallyflex duct too. So I would examine that & the return/supply air duct for quality & holes. Maybe the floor ducting has collapsed. Have you noticed a decrease in air flow as the cooling diminished ?? Changed the air filters ??? Examine the evaporator coil upflow side for dirt on the fins. Does your model have attic space ?? Have lots of insulation in it ?? Heat load hasn't changed so I'd still bank on air flow. Check it out good.
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QUESTION: Thanks for the quick reply. We are in the process of checking/sealing all the duct work underneath, we already checked the crossover. I havent noticed the air flow dimishing but we had the inside and outside coils cleaned professionally (one a/c tech) and i did notice a pickup in the air flow but it didnt make that much of a difference in the temp in the house. All vents seem to be blowing the same so i dont belive we have a collapsed duct. I try to keep up with the air filters. The model has room for attic space in every room except the living room which is right in the center of the house but i have no way to get into that space. They told us it had good insulation but i dont know for a fact but for the first 4 or 5 years i dont remember having any cooling problems. Would it do any good for us to pull out the blower motor and clean it? No one has ever done that. I understand the supply ducts but the return? What/Where is the return?
Answer This sorta IM, right ? I'm retired so check in often. Keeps my brain active.
The return is onthe front of the furnace or maybe underneath it. Check it out. You can see the blower wheel somehow on the unit & the dirt on the ribs can tell you whether it needs cleaning. A little dirt on them can sure reduce the capicity.
