One question I often hear from HVAC professionals is "Doc, if there was just one thing I could do for each system to improve performance the most, what would it be?" Let's take a look at the answer to that question as it pertains to your specific role in this industry.
For installers, seeking just one thing you could do for every system you install, the answer would be: Assure each return duct installed in an unconditioned space is completely sealed and that the proper duct insulation has no gaps.
Return duct leaks from ducts located in areas surrounded by hot or cold air such as attics pose the greatest threats to a system’s efficiency that usually goes undetected for the life of a system. A 300 CFM leak through a return duct in a hot attic can easily pull in enough heat to reduce cooling system capacity a ton or more.
To verify the job is done right, when the system is started up, measure the air temperature entering the return grille farthest from the equipment and subtract from the air temperature entering the equipment. The difference should be less than 10% of the temperature change over the equipment.
For maintenance techs, seeking just one thing you could do for every system you maintain, the answer would be: Ask each customer which of their rooms is the least comfortable. Then spend 5 minutes searching for an obvious solution to their problem.
Go beyond your normal checklist and make a change for good that your customers will appreciate for years to come. Adjust louvers on a supply register; open a damper that was installed in the closed position 10 years ago. Connect a broken duct in an attic or discover the insulation that was never installed above the master bedroom. Your customers will love you and remain loyal for life.
For service techs, seeking just one thing you could do for every system you service, the answer would be: Measure total external static pressure and measure the temperature change of each system. Then record it inside the equipment.
This one thing will provide a benchmark of that system’s performance that you can refer to each time you or someone in your company returns. This will allow you to determine if airflow or the temperatures of the system have changed since your last visit. Begin to include the duct system in your services by measuring static pressure. Recording temperature change will allow you to track any change in the systems performance immediately.
For designers, seeking just one thing you could do for every system you design, the answer would be: Begin oversizing ducts starting today.
Here at NCI we daily gather test data from around the country from HVAC contractors testing the airflow performance of duct systems. This data confirms that nearly every duct system is undersized and performing poorly. Yet airflow is invisible and rarely measured, so this problem goes undetected.
As we review the improvement in the performance of the system after NCI contractors upgrade and renovate systems, we see evidence that the contractor installed additional duct capacity almost every time.
Ducts are either too small or the duct installation quality is extremely poor in almost every system. One solution is to increase duct size. If you're a designer and you disagree with this recommendation, send me one of your air balance reports to justify your position and I'll believe you.
For salespeople, seeking just one thing you could do for every system you sell, the answer would be: Include some form of HVAC performance testing on each sales call.
Do something to differentiate you from everyone else that is just box swapping and trying to win the race to the bottom price.
Testing sets you apart from your competition and distinguishes you as an HVAC professional. The reason to test is that testing identifies unseen system defects. Testing will help you find, and then provide the solutions your customers are really looking for. Most companies imply new equipment will solve comfort and efficiency problems, but new equipment cannot solve most comfort and efficiency problems.
For contractors and company owners, seeking just one thing you could do for every system your company is responsible for, the answer would be: Encourage your people to pull their heads out of the box (the equipment) and lead your company to find and deliver custom solutions your customers have been asking you to solve for years.
Take the initiative to lead your team beyond what everyone else does and build a company that becomes more than box changers.
This industry is overflowing with low bid box swappers who ignore the air distribution system. Delivering efficiency requires more than promoting a big number on a yellow sticker.
The challenge here is to move into a position of leadership, rather than to simply follow what everyone else has been doing for decades. This is an individual effort that brings a sense of satisfaction to your job that is only enjoyed by those who choose to go the extra mile and offer something more.
Rob “Doc” Falke serves the industry as president of National Comfort Institute – an HVAC-based training company and membership organization. Got feedback? Contact Doc at [email protected] or call him at 800-633-7058. Go to NCI’s website at nationalcomfortinstitute.com for free information, articles and downloads.