sizing & quote for AC

16 years ago

I need some objective advice on an AC compressor and coil. Everyone

I talk to has a different opinion on tonnage, hybrid, and price and I'm trying to sort through the salesmanship and get to the best solution.

This unit will be paired with a 4-ton Trane XV95 gas furnace, which is 1 year old. Th current AC is a 3 ton unit, R-22, about 11 years old. It would be cooling the first floor (2200 ft.) of a two story home built in the 1920's.

It is a 3-wythe masonry cavity wall system, so not a high very R value. Original single pane windows, in various stages of repair but well on their way. Storms to be added. No insulation under the floor in the basement, and no immediate plans for it. The upper 2000 ft. is served by an XL16i heat pump. The attic is freshly insulated. The stairwell between floors is open, so that should be taken into consideration. The building will be used for office/institutional use primarily, but there may be times when I have 20-40 people inside.

First, I've had recommendations for 3, 3.5 and 4 ton systems here, and at all SEER levels. I'm also getting differing opinions on wether to add a heat pump for a hybrid system, even though my furnace is pretty efficient. Southern climate here, end electricity is regarded as cheaper than gas generally.

I'm leaning towards the 15 or 16 SEER range. Mostly have been quoted Trane equipment, probably since thats what I have. I have also looked into Goodman, and not opposed as long as its installed correctly. I've looked into this extensively & it probably is more about installation than equipment.

Any compelling reasons not to pair brands differently?

Does the heat pump option make sense or is it a waste of $850?

Will I see a big difference from 15i to 16i (single stage vs. dual stage)

some rough numbers I've been quoted, all include coil, line set, drains, pad, wiring, permit, etc..

XL15i: 6300 for a 3 ton, 5100 for a 3.5 ton

XL16i: 6500-6700 for a 3 ton, 6400 4 ton

in each case the dual fuel option adds about $800

Oddly I got one quote for an XL16i for around $4500

Seems extremely low, should that be a red flag or a potential blessing?

Not as big of a company as the others, but they are listed on Trane's website.

What am I missing here.

The Goodman products come in at under 5K.

Any insight appreciated...

Sort by:Oldest

Comments (3)

tigerdunes
16 years ago
splinters

so this is an old home used exclusively as institutional/commercial office space?

I would forget the heat pump since you are in a southern climate and have a 95% eff gas furnace.

I would insist upon a load calculation for correct AC sizing.

I would forget about the XL16i because of your location and relatively mediocre dehumidification properties of this premium condenser.

I assume since this is commercial property and you were not eligible for the HVAC tax credit. Correct?

I would consider the XL15i or XR15 AC condenser with best matching Trane evap coil. No third party brand!

you need the right thermostat for this system. What was originally installed?

And I would get a good 4-5" pleated filter media cabinet if not already installed.

IMO
splinters
Original Author
16 years ago
Yes, thats correct abut the usage - trying to give an old place a new life.

Funny how no one wants to do a load calc., they all eyeball it and all have a different answer. Even if they did it how can you be sure they aren't skewing the results? One company told me I should consider 20 seer. I'm not that naive! I'm sure it needs to be between a 3 and 4 ton, but would there be a huge effect on performance between the extremes?

mediocre dehumidification? is that because of the design particular to that unit and will the 15 handle humidity better or worse? You'd assume that the 2 stage unit would do everything better. The salesman says that when its not very hot/light load I'll save energy on cooling.

you are correct about the tax credit.

I'm still using an old mechanical thermostat, just now occupying the building and was planning to change it out. The other system uses a Trane/Honeywell, VisionPro I believe.
Related Professionals
Crestview General Contractors · Spring General Contractors · Olean General Contractors · Plattsburgh General Contractors · Eureka General Contractors · Victoria General Contractors · Atlantic City Home Remodeling · Columbus Home Remodeling · Anniston Home Remodeling · Grand Rapids Home Remodeling · Salt Lake City Home Remodeling · Ottawa Home Remodeling · Grand Island Bathroom Remodelers · Lebanon Bathroom Remodelers · Newark Bathroom Remodelers
tigerdunes
16 years ago
splinters

what is location?

I would not have the XL16i. If dealer would substitute the XL20i for same price, that would be the way to go. Otherwise, get a correctly sized XL15i or XR15.

You need the correct stat. At the very least that would be Trane's 803 with humidity sensor or identical HW equivalent.

If you don't already have an air filter cabinet, then add a 4-5" pleated filter media cabinet. Very easy changeout and filters usually last up to one year before changeout is necessary.

IMO