I'm looking at new AC units. I have been quoted for the Trane XR 14 Variable Speed unit, which is not Energy Star Rated. I have been told that for the same price I can get the XL 14, which is Energy Star rated, but the unit would not be Variable Speed. Which would be the most energy efficient solution? Thanks for any help!

First worry about future repair bills. The variable speed systems cost big $$$ to repair when the motor or controller go bad.

As far as efficiency 13 SEER is the lowest base number and as it goes up the efficiency gets better but not that much better. A 14 SEER over a 13 SEER is usually not worth the extra expense for a standard size home unless you live in Death Vally and run your A/C system for 24 hours a day all year long.

What it comes down to is a 14 SEER is better than a 13 SEER BUT at what initial cost and how long is the pay back?

The most important factor to consider when replacing a unit is actually has nothing to do with the SEER rate. A poor install can take that new 14 SEER unit and make it a 10 SEER or 12 SEER unit during the final check out and charging phase of the install. Here is a small article that talks about HVAC service people and how untrained they are in many cases. The most important thing you can do for yourself is to make sure the people who install your system are NATE certified. Not just the company but the employees actually doing your job. Most good installers/repair persons are proud of there NATE certification and will be glad to show you there credentials.

Typically, the Energy Star rated equipment would be considered more efficient, but I am surprised. Are you sure someone didn't get that backwards? Both having a SEER rating of 14, I don't understand why the variable-speed system wouldn't be the more energy efficient of the two. If you like to run a continuous indoor blower, the variable-speed may cost less to operate even if it doesn't qualify for the ES rating.

Thanks for the information. We don't live in Death Valley- but pretty close- Arizona.

So, with the variable speed costing more upfront and more to repair, it doesn't sound like it would be worth it, even if it does provide more efficiency. Is this correct?

No one-size-fits-all answer to that. Research both options and choose what you feel is best for you. F.Y.I. I am NATE certified (and re-certified) in heat pump service and installation. I would be more than happy to come out to AZ at your expense for any service needs you may have, especially now (cozy 18 degrees here). GO CARDINALS!! BEAT THOSE LOUSY STEELERS!!

, with the variable speed costing more upfront and more to repair, it doesn't sound like it would be worth it, even if it does provide more efficiency. Is this correct?

Let me answer this way. There will be no (factory) variable speed products in my home. While the factory variable speed products do work the failure rate is high and the cost to repair out of warranty is very expensive. What it all comes down to is logic and common sense. Always look for the best and biggest bang for the money and lay off the expensive extras unless you really need them.

Thanks for all the information! I'm going to pose some more questions back to my HVAC contractor and probably lose the VS aspect from the quote.

For KC- you'd be surprised how many Arizona Cardinal bashers have converted to faithful Cardinal fans lately. Guess we need to ride the tide while it's high!