Rheem vs. Trane Condensing untis

[jbrscot]

I've read through many of the posts on this site regarding differences between many manufactures. Most have been for air handling units. I'm looking to buy a 3.5 and 4 ton unit for a 3,000 sqft new construction in new england. Getting prices on both Rheem and Trane 14 seer condensing units. These will be paired with Unico air handlers. I know the SEER ratings will be only around 10 but I am going with the higher SEER in order to get an energy star rating, and thus a rebate. My question is mostly of quality. Will the expected life of these units be less because of the Unico?

[BaldLoonie]

RAMC042 10.00
RAMC048 10.50
RAPC042 10.50
RAPC048 11.00

2TTR2042 10.50
2TTR2048 11.00
2TTX4042 11.00
2TTX4048 11.00

Doesn't make much sense to buy more than the 12 SEER outdoor unit. Big jump in price to the 14 SEER for virtually no difference in effective SEER.

Which brand is a matter of preference. Both are fine units. The TTX Trane has more bells & whistles than the RAPC but will be pricey!

[jbrscot]

Good point Bald. What about the effect of the Unico on these units? Is it going to wear the condensers out faster?

[BaldLoonie]

I really wouldn't see how they would cause any more wear on the unit than a conventional air handler. There are still a few ancient Dunham-Bush outdoor units on the origial Space Paks from the 60s running around our area.

[billva]

there will be more wear on the compressor/OFM due to the effect of the freeze stat in the unico.

[docholiday]

I cant believe a utility is allowing a rebate based on the outdoor unit alone, they generally want to see an ARI matched System rating.

[billva]

new construction?

why unicos?

[BaldLoonie]

The utilities around here only care about an ARI rating and they can get that with a Unico, which is where I got those ratings. Of course, high velocity systems won't qualify for any kind of efficiency rebate

billva, I was kinda thinking along the lines of cycling on a freezestat as being a little more wear too. And also wondering why using a low efficiency system on new construction. For the same money as a SEER robbing Unico, one could get a SEER boosting VS air handler with dehumidifciation (which is one argument HV lovers use in favor of their equipment).

[jbrscot]

This is a new construction. The rebate is part of an overall energy star score for the house, not just for the AC. I had to upgrade windows, insulation and air sealing as well. Going with the Unico because I have a gas furnace now and it is very drafty. The Unico hopefully will make for a nicer environment. Plus the added dehumidification. Another plus is the asthetics. I like the smaller diffusers.

[jbrscot]

Also had to upgrade the boiler from an 80% efficient oil boiler with a tankless coil to a Buderus G215/4 @ 86% with an indirect DHW heater.

[filterboy]

the unico rep who taught a class on the high velocity systems in my area said they should only be used with a 10 seer condenser

[tpa-fl]

If it's new construction, Unico seems like an odd solution... unless you're dealing with some very difficult aesthetic conditions (glass curtain walls,etc), I think there's probably a better solution out there. In my condo remodel (okay, total gut), I had linear bar grilles installed along one side of each room (bathrooms the exception, used more traditional ceiling diffusers in there). The grilles go the entire length of the room and actually add to the rooms' aesthetics. I forget the exact dimensions, but they're very thin. Beacuse of the length, the surface area of the grille is actually larger than a traditional grille/diffuser, so noise has been virtually eliminated (<18dbA for most rooms)

[robert morrison]

I'm using Unico in my new construction (New England) for its space savings. The trade-off between lower operating efficiency and smaller first cost is easier to make in favor of smaller first cost when the operating (cooling) season is relatively short. Hopefully, a higher space temperature setpoint will be comfortable and offset the reduction in operating efficiency.

[casturbo]

I recently saw the finished installation of a 4 ton Unico system in an old house. I think the installer said he had to use 6 outlets per ton, so there was over 20 holes throughout the house. YUK!! the poor house was swiss cheesed!! Kinda like huge termites ate holes everywhere. Then, there was one mammoth return upstairs and one downstairs, the return grills were bigger than my Weber gas grill that I'm able to cook 16 burgers on!! I guess the HO will know where all the kids toys will end up, hopefully stopped by the air cleaner!!

[Modman]

I cannot fathom why anyone would even consider a Unico in a new construction setup. I would make/add the space.