Our house is 2600 SF, R33 ceiling, R-12 (I think) in the walls, slab floor, home built in 1978. 1600SF then, 1st owner added about 400SF, we added about 600SF more. All duct work was too small. All new duct work, proper sizing, extra air outlets installed (all this was done around 2002). Our electric utility sponsored it. It cost us around $2000...utility a few hundred more.
The installing contractor (1991) said: "Unit has a 3.5 ton A/C for a house of 2600'. Present air is not enough to handle a 5 ton unit without changing furnace. We recommend a 4 ton exchange. If 4 ton unit is not large enough to cool to comfort. We will replace with a 5 ton furnance, A/C and coil (at average bid price) and reimburse this price." ($1680 was the price).
The unit is now over 17 years old, has NEVER been serviced and when it was
103 today, it kept the house at 78. Pretty good I think. I am on oxygen & a Ventilator due to Respiratory problems, so the ducts have to be cleaned every so often.
The contractor said our furnace is 100,000 BTU and for some reason, he did not think the 5 ton AC would work. Maybe the ducts were too small?
I apologize folks, I am on morphine for pain and my memory is shot. With newer, much larger ducts, more registers which are larger, with air returns and a 3rd HEPA filter inlet at the ... uh ... fan, it would seem the larger unit would work.
The SEER in the brochure says 9.45. Our electric is about $.16 a KW on the upper end. If we modernized to a higher SEER, any suggestions as to what unit to use? Our Trane has never been serviced. Yeah, it needs it. But ya gotta admit, it is still doing great. If it isn't broken, don't fix it??? With my luck, I get it serviced and it melts down the following week.
Any suggestions appreciated......