1991 Trane XE-900 question.

[1991xe900]

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......

[amd]

If the existing unit is cooling fine do not get a larger size.

Oversized equipment short cycles and removes humidity poorly, not to mention the upfront costs and high energy consumption.

I would spend money on energy efficiency upgrades before replacing a working unit.

[sammy37]

Where in central Ca are you? I spent many of my younger years in the lower foothills above Fresno just below Yosemite. The humidity is starting to get worse around there, you dont want to go with an oversized unit, (poor humidity removal) not to mention other issues. I dont know how people out there can afford to run a/c anymore with the price of electricity. My dad suffers with a swamp cooler out there because he refuses to pay high electric bills.

With those electric rates, you should try to get the most efficient unit that you can afford.

[1991xe900]

Thank you. I believe in Maint. on things, but that Trane has never missed a beat and I kind of hate to even get a service call.

Since it was installed we flooded in Jan 1995 (only about 18" deep), so we replaced our windows with dual pane e gas Milgards, increased the attic to R-33, put a patented roof on. It is Monier Premium Duralite tile with channel iron used to hold the tiles in place. The channel iron has slots cut in it for ventilation, so the entire attic stays around 20 degrees cooler.

We also had a 36 inch whole house fan installed. Now we can't use it due to my respiratory problems. I am not sure what else we could do to save electricity.

On the bright side of things, some electric companies will give a person on life support equipment a large break on their electric bill. Like approx. 33% for PG&E in California. It sure helps.

The only other thing I can think of to do is have our son cover the ... the ...
cooling pipe (?) that goes from the Trane up into our attic. I think the UV rays ate the foam up. That is the only thing I can think of that might be needed. Since we were told we needed a 5 ton originally, we thought we might need to do one final upgrade. The unit is 17 years old and I am not sure how long a person can expect them to last. It could take several days to get it replaced in a heat wave...and I couldn't stay here during that time.

Anyone have any idea how long an AC unit should last? Ballpark? 20 years?
25 years? Thanks again....

[1991xe900]

Sammy37...
I flew out of Castle AFB at Merced for many years (77-82) and spent a lot of weekends up at Fresno Dome, Oakhurst, etc.

We are in a suburb of Sacramento now. Bought 3 decades ago..an acreage, now we can't take care of it. Luckily the Gov. declared a drought, so my wife does not have to mow it. I am not kidding, I can't go out there. It is complicated, but if I pass out from any reason, or even fall asleep when I am not on my Ventilator, I have a good chance of dying. CCHS is the name of that disease. Very rare. Anyway, I stay inside all the time. Drives me nuts, but I am trying to be patient. My Medic Alert dog has saved me 4 times in the last couple of months. She alerts and either wakes me or gets my wife. Weird life.

[smittyii]

there are too many variables to consider on life of any system, but 17 y.o. is pushin it. it might be wise to put $$ aside just in case. God bless.

[1991xe900]

I understand 17 years is pushing it, that is why I asked what would be a good unit to replace it with.

By the way, my wife was saying we should just use it until it breaks down. With my health issues and growing intolerance for temperature change ... I thought we might wait until this winter to see if anyone is having a good sale.

If we replace it with another 4 ton, we might save some money. We really noticed a huge change in cooling/heating when the duct work was enlarged.