Low HVAC Bids Often Mean Corner-Cutting

Learn the basics of HVAC so you can evaluate subs' bids and ensure correct installation.

If you're in the business of building custom homes, you have to consider many factors when selecting your trade contractors, and a sub's ability to offer you the lowest price is certainly one of them. In fact, it's all too easy to think of the HVAC end of the business as yet another commodity. You simply go with the lowest bid that doesn't get you in trouble.

Furthermore, if certain technical aspects of the business (such as HVAC, electrical or plumbing) aren't your area of expertise as a builder, it may be tempting to leave such matters in the hands of contractors who are the so-called experts.

But it isn't their home you're selling—it's yours—and your reputation is on the line. So I recommend you take the time to learn just a few of the basics of each of these fields to make sure the homes you’re offering are truly the best in your market for the price.

Did you know, for example, that the cheapest air conditioners available from all manufacturers are called the "builder's models"? When examining multimillion-dollar homes, I still find builder-model air conditioners being used, so I can only assume that taking the lowest bid must be a consideration for even these homebuilders. Let me give you some idea of the quality of these models: I was recently in a new home that cost a friend of mine close to $1 million, and whenever the AC unit kicked on, they had to turn up the sound on the TV to hear it over all the noise coming from an undersize central return air.

Understand that low-bid subcontractors must cut every corner to be competitive, so they choose the cheapest—and therefore the worst—HVAC systems, ductwork and diffuser grilles. Occasionally, their cost-cutting measures can even become standard practice.

If you're old enough, you can remember when every room in a home had a return-air duct. But you don't see them in more recently built homes. Some low bidder figured out that they aren't needed if you undercut a home's bedroom doors enough to allow space for the air to return—a stupid idea, but one that's now commonly practiced.

Also, unless you're building large houses, it's common to see flexible duct making up all the ductwork in a new home today. You should recognize, however, that very little real engineering goes into the HVAC design when flex duct is used. Long runs of flexible duct are inefficient at best, and no one can estimate the losses in all those bends, twists and turns.

Yet another corner often cut by low-bid HVAC contractors is eliminating the inexpensive "balancing dampers" required to get the correct amount of conditioned air into each room. (Have any of your customers complained about a room being too hot or too cold? Aha!)

There are many other factors—from the need to use dry nitrogen when brazing to simply correctly sizing the system—you should consider when selecting your HVAC contractor. While those factors are too numerous to list here, the point is that you need to take the time to do some basic research on the fundamentals of the HVAC industry before you hire an HVAC subcontractor.

Arming yourself with the knowledge you need to make sure your HVAC systems are installed correctly will enable you to seriously consider an HVAC subcontractor's engineering expertise along with the bid price he offers. Only then can you decide if that low bid is truly the best bid.

Jim Wheeler is an award-winning writer and teacher with more than 25 years of experience in the HVAC industry.

Remodeling Photos

Projects by Professionals(at Pro Galleries)

  • Traditional Kitchens
  • Traditional Home Theaters
  • Modern Home Theaters

Projects by People Like You (at Rate My Remodel)