by Dominick Guarino
A couple of weeks ago, I found myself staring in disbelief at the cover story headline and photos of an HVAC industry publication. I also checked the date to make sure it wasn’t April Fools Day.
The article was about a study performed by Lawrence Berkely National Labs (LBNL), advocating the use of “duct-taped laundry baskets” and garbage bags to measure airflow and system performance. They went on to say that these homemade devices were just as good or better than flow hoods calibrated to ANSI standards.
For those of you who don’t know LBNL, it’s one of several labs funded by the Department of Energy (DOE) to perform energy research. Several of the “experts” at this lab conducted a research project a few years ago involving flow capture devices. The study concluded that “Flow capture hoods can be off by as much as 30% in residential applications!” I think several hood manufacturers would beg to differ with these findings.
Where do I start? First, how good was the study? How do we know these “experts” even know how to use a flow hood properly? Many of their statements about how HVAC systems work lead me to believe they don’t.
They attribute the margin of error largely to “grille airflow non-uniformities” In English, they’re saying the air doesn’t come out of the grille evenly. Duh? Talk about stating the obvious. The issue is knowing how to use a hood, and when to use other testing methods when a measurement is suspect. How do you know if there’s a problem? With training and real field experience.
Thousands of people use flow hoods every day on residential style grilles (which by the way are also quite prevalent in small commercial applications), with accurate, repeatable results.
Second, is this the image we want to portray to our customers? “Ma’am, I’m here to test your system with highly sophisticated measurement devices ¯ do you happen to have a Hefty two-ply I could borrow?” Or, “I need to balance your system for even comfort. Can you empty out your laundry basket so I can take some measurements?”
One of the “scientists” had the gall to suggest you put your logo on the garbage bag and leave it behind so the “housewife” can show her husband the high-tech device the contractor used to diagnose the proposed $3,000 duct renovation. At least the homeowner now has something to put the proposal in…
It’s obvious these guys don’t have a grasp on the realities of contracting, let alone any business sense. They also show little understanding of HVAC systems.
ARI and ACCA are investing heavily in task forces aimed at improving our industry’s image. I don’t think duct-taped laundry baskets and garbage bags quite fit the image we want to portray.
If you also feel this is a mockery of our industry, write DOE and let them know about it. Is this the best they can do with the millions of taxpayer dollars poured into these programs each year?
Here’s a cost-cutting idea for DOE that could slash LBNL’s budget significantly next year. The next time they ask for several hundred thousand dollars to fund an “energy saving” project, give em 10 bucks and send ‘em to the Dollar Store for their lab instruments!
I’m not sure why these guys have such a disdain for our industry’s instruments and methods, but this time they crossed the line. Maybe they’re upset because it took them 10 years to figure out something some of us already knew: the HVAC system is one of the most important contributors to home performance.
Measuring airflow and balancing can make all the difference in system performance, comfort, and efficiency. But let’s make sure we use professional, proven test instruments to do the job right.
Dominick Guarino is CEO of National Comfort Institute. He can be reached at 800/633-7058, or at firstname.lastname@example.org.