There's a myriad number of ways to come to a price. Just as much there are a myriad number of ways to run a heat load calculation, just as much as there are a myriad number of ways to design a duct system / and or run that duct.

There is unfortunately no quantifiable way to make a educated guess as to which of these choices measure up.

How old are the current HVAC systems in the home? Have those systems adequately cooled the home when the machines were younger? If you don't have that information --- you may be back to guessing.

A heat load calculation is not fool proof. It is a guess, based on information you feed into the calc. If that information is wrong... the guess is no better.

I'm not in the Trane bandwagon I feel there are better solutions... but that's me. I work on HVAC systems fix them for a living -- nearly 26 years. Got tired of the Trane gimmicks and the constant blame game. You talk to others, you'll get more differing opinions.

Air Conditioning is big business and everyone is trying to convince you -- they butter there bread a little better than the next guy.

I service the Katy, Texas area.

The systems were put in when the house was built in 2004. We bought the house in 2013 and they cooled well. The trouble now is the fins on the outdoor unit are falling off the outside unit and our electric bill is extremely high in the Summer.

It is good do your contract did a load calculation, but then he is choosing to ignore it. I guess he doesn't trust his own calculation. He is over sizing the one of the condensers, and then over sizing the furnace to compatible with the over sized condenser.

For the master bedroom/upstairs bonus room side, the heat calcs were 15,879 btu/h heating load and 18,771 btu/h cooling load.

This should be a 2 ton AC with the smallest furnace (40K?) that is compatible with the condenser. You don't have to modify the duct work if it is good condition.

The rest of the house heat calcs were 26,405 btu/h heating load and 34,866 btu/h cooling load.

You said the current 3 ton AC worked well. Then another 3 ton (36,000 BTU) AC should work fine. No need to be increasing the size. Again the smallest furnace should be used since you only require 26K BTU of heating.

I would not spend money on UV lights. A 4 inch media filter would be my recommendation.

My electricity is 10.5¢/kwh here in Port Neches, TX. I average 2,300 kwh per month in the winter and 6,200 kwh per month in the summer.

Thanks Mike for interpreting the heat calcs for me.

Here's something else to consider when it comes to the Trane brand of equipment. I'm pretty sure my assessment is more than spot on when it comes to this brand. These kinds of things were occurring randomly when I worked for an American Standard dealer over 13 years ago. Here's the thread.... Odd Trane noises new equipment install.

With that said, your electric rate not being the problem... 4,000 KWH difference in the summer the problem is most likely the AC's.

If you go with a 2 ton unit for the Master& bonus room. The difference from 2 ton to 3 ton is negligible as to what it will cost you to operate it. The furnace is a two stage, so worse case it runs in first stage all the time.

A ton of cooling more capacity for the Master & bonus room? The bonus room is a upper floor room right? hot air rises right?

Hard to say if that is the reason why the builder did what he did. But if 3 ton and 3 ton worked well before?

What is your reason to change that? A heat load calc, that might be fraught with a mistake or two. You, I, nor anyone else knows it was done right?


That extra 1 ton of cooling may only come into play in July / August if you use that bonus room in those months and were under a 30 day heat wave of 100F or more.

If we were talking some other area other than Texas, I might have a different opinion.

How cool do you like to keep the home? What temp. setting on the thermostat?

For OP...if your load calcs are correct, it would seem that you could go down in size both AC unit to 3 ton, furnace to 60 K On larger system.

I am not going to comment on pricing but if you want Trane, then call in an American Standard dealer. AmStd is Trane’s sister Company and has exact same equipment as a Trane dealer quoted you. Usually they are less expensive. At least that would give you a comparison.

good luck,

TD

The Trane systems are top of the line multi-capacity systems (like a multi-multi stage system). Being a little oversized isn't as bad as with a single stage system (especially in your neck of the woods where dehumidification is a significant consideration). But as Mike Home says, you could probably get away with smaller systems.

Unless they are going to throw in the add-ons free to clinch the deal, I'd pass.