Air Conditioning - Trane XE 800 High Efficiency

I have a Trane XE 800 High Efficiency Air Conditioner, model No. TTJ736A100A0 (not sure if that 3 might be an 8), SN: 006268711. This unit was manufactured in 2/89 and installed new the same year. It has worked wonderfully the past 20 years with no problems. Still has no problems; however, I have read that an AC unit can only be expected to last 10 to 12 years and NEVER more than 20 years. So, I figured I had better replace it. I have had it checked by a representative from a local Trane dealer about every two years and they have never found any problem with it. But, if it CAN'T last more than 20 years, I guess I should replace it. However, my local Trane dealer has moved somewhere and I never asked him what size unit this was. I have 2000 sq ft home. Can anyone tell a how many tons unit this is and what size I need to replace it with these days?

model No. TTJ736A100A0
I have 2000 sq ft home. Can anyone tell a how many tons unit this is and what size I need to replace it with these days?

The 36 is 36,000 BTU, 3-ton unit. I'd say it maybe the right size, but the best thing to do is find a good dealer who does do the load calc (Manual-J) load for your home.

Not sure if you have done any windows or insulation update on the home over the years, but if they have been updated or what not, then you may be able to use a smaller system.

If all is good, then the system may last longer, but you may not be saving since it's a lower SEER unit, and you are down south where you do use the A/C more. It may pay off to get a higher SEER unit.. Today's 13 SEER is the lowest you can go, you can go as high as 19 SEER with Trane's two stage system. Also, if you get a new system, it may be best to go with a Heat Pump system, and don't have to depend on gas as much.

I'd stick with gas heat if it's available.

I'm not sure how cold it gets in Georgia, but heatpumps will run about 2 SEER lower for each model than their comparitive condensers. Gas heat gives you a 30 to 60 degree rise in temperature in heat mode. Heatpumps would not.

That said, if your furnace is as old as your condenser, you should replace it as well.

Thanks for the information all. So far I understand that it is a 3-ton unit, that there are mixed opinions on whether I should switch to a heat pump or stay with gas. And it is suggested that I replace the furnace as well. Damn, I didn't know or plan on the furnace. $$$. I like gas heat and feel that a heat pump leaves you kind of luke warm and luke cool. I am upgrading to new double pain windows with argon gas and UV filtering "Low-E" glass, which are Energy Star qualified AND meet the tax credit criteria, and have U-factor and Solar Heat Gain Coefficient both < 0.30. As for the AC, I figured all I would have to do is buy a new 3-ton unit (Trane?) and have it installed outside in place of my old one. Do I also have to look at inside components? My heater and blower are in the basement unit. Is my AC condenser there as well? I obviously don't know anything about ACs. Can I just replace the outside AC unit? I am dreading the answer. I should probably start by finding where my local Trane dealer moved to, and have him out to evaluate my system and tell me what all I might need and the cost.:(

that there are mixed opinions on whether I should switch to a heat pump or stay with gas.
For your area, Heat Pump is an ideal thing to have.. I know a lot of homes here in this area are going that way. Gas price is not going down. You can still use gas heat as a back up when the temps fall below 20's˚ when a heat pump is not doing the job.


I like gas heat and feel that a heat pump leaves you kind of luke warm and luke cool.
Heat pump now days are far better than the old heat pump that felt "cool". and if you get a matching furnace with variable speed blower, you will feel just fine. Variable speed blower will be slowed down to have a higher heat temp out of the vents.

As for the AC, I figured all I would have to do is buy a new 3-ton unit (Trane?) and have it installed outside in place of my old one.

With the updates you are doing, chance are you won't need a 3 ton unit.. You may be able to go down to 2.5 ton or maybe 2 ton.. It all depends on what the Manual-J (Load Calc) comes back to.

You can download your own for $50 (http://hvac-calc.com/main.asp), it will be the best $50 you've spent to get a unit that will make you comfortable!

If the dealer comes back with a larger sized equipment than what the results come back, ask for them to see the results. If they don't do it, move on to the next dealer.



Do I also have to look at inside components? My heater and blower are in the basement unit. Is my AC condenser there as well?
Yes, you need to replace the A-Coil downstairs on your furnace. and should replace the line set between the coil and unit outside (Condenser).

Thanks Jay11J. Sounds like good advise. Maybe I should rethink heat pumps, it was over 20 years ago that I experienced one that wasn't too hot. I saved the link you sent and will check that out before I get with a dealer. Thanks again. It may be a while before I act on this and when I do, I'll probably be back then with more questions.:)

Sounds like a plan.. Keep us posted on what you end up doing.