You've already heard about the not-so-subtle changes you might expect from the move to the minimum residential air conditioning efficiency standard of 13 SEER. Condensing coils will likely become more complicated to clean. (Ever separate a three-row coil?) Evaporator/condenser coil matchups will become even more critical. (Ever explain to a customer why the utility bill didn't actually go down after the purchase of a high-efficiency unit?)

Sure, you already know about some of the complications, and probably a few that some of us haven't even thought about yet.

Here's one that you may also be aware of: large indoor air handlers won't fit very nicely in the precious space provided for mechanical systems in most new home construction designs. If the majority of your low-side installations are in a basement, it's not as big of a deal. However, a contractor in Sarasota, Fla., asked us to write an editorial to give him some ammunition to combat what I've dubbed "efficiency ignorance."

I often take my cues from HVAC contractors, just not always this directly. However, Guy Peluso has a point that is certainly worth making.

According to Peluso, who is already a contractor promoting high-efficiency installations, the closets and attics of new home designs aren't always big enough to accommodate the appropriately sized air handler. When he attempts to explain this dilemma to not only the builder, but also the prospective homeowner, neither can fathom why he's so crazy.

Really! All he has to do is install a box that fits the space provided, they think; don't bother us with your little problems - just get the job done.

But, let's be fair. Home builders and prospective homeowners certainly aren't required to understand all the nuances associated with the installation of a high-efficiency air conditioning system. It's your job to educate them about the comfort system. The real problem lies in the fact that builders and customers won't necessarily believe that you're telling them the truth.

It's No Small Matter

"They think I'm lying when I tell them the proper indoor unit won't fit through the scuttle hole in the attic, and I'll have to make the hole larger, sometimes ripping out ceiling joists," said Peluso.

If a closet installation is specified in the design, the newer, bigger units will demand more space. If the builder won't adjust the drawings, and won't permit the installing contractor to build a bigger closet, the contractor may have no choice but to put in an undersized air handler. That's a bad choice.

If perhaps the builder would allow for any field adjustment in the attic or closet design, would the contractor be allowed to charge for that extra work and service? This is a touchy issue. The best solution is to get the message out to builders that square pegs won't fit into round holes - at least not without a fair amount of coercion. Coordination of design is critically important.

Builders should know that one of the ramifications of increased efficiency from an air conditioning unit is very often a larger indoor unit. Variable-speed blower motors enabled many of the gains in efficiency that had been accomplished over recent years.

And, these efficiency gains have been mandated by the Department of Energy (DOE). After Jan. 23, 2006, manufacturers can no longer build condensing units with efficiencies of less than 13 SEER.

The air handlers that are required to match up with these higher-SEER units are almost always bigger than their predecessors. It has to be that way in order to get the true efficiency from the comfort system.

There, Mr. Peluso, we hope this information will be helpful in your quest to educate not only builders but also your homeowner customers. However, a greater hope is that more contractors take on the task of properly educating everyone in the value chain that things are going to be changing once the new DOE standards have been implemented in the HVAC industry.

Now, if any other contractors have some good ideas for our Insights page, just let us know.

Mike Murphy is editor-in-chief. He can be reached at 248-244-6446, 248-244-2905 (fax), or

Publication date: 03/14/2005