Since the 1960s, engineers have required air balance reports to assure their designs work in the field. These reports gather multiple HVAC system measurements and put them in a single form that shows a complete picture of true performance. Could you benefit from using a similar report?
From Commercial to Residential
Air balancing has its roots in commercial and industrial HVAC. In this world, individual testing, adjusting, and balancing (TAB) professionals “fine-tune” the installing contractor’s work and document the quality of the final product.
The balancer records all measurements and test results on an air balance report. Once testing is complete, they compare their readings to manufacturer specifications or engineered drawings. If everything is within specifications, they submit the balanced system. If balancing is unattainable, they make a list of deficiencies and repairs for the installing contractor to correct.
Residential HVAC professionals across the country now use many of these same principles in various and creative ways. They are the balancers. They use proven air balancing tests to diagnose airflow issues, verify the quality of their work, and prove their systems perform as designed.
A Residential Air Balance Report Is an Assurance Policy
Air is an invisible part of the systems you design, test, and repair. Low airflow equals low comfort and high operating costs. Unfortunately, these problems show up as a disappointed customer. You can avoid that by fixing many issues that lead to their concerns before they ever know about it. It just takes a bit of testing.
A residential air balance report is a single page that is part of a larger report package. It provides a place to record the information that identifies various system problems.
If conditions exist that prevent the system from operating as designed, the contractor can discover the issue and fix it before it results in a callback or equipment failure. Without the information on an air balance report, many of these issues remain hidden.
The report assures your system works as designed and your customer gets what they paid for.
A Residential Air Balance Report Puts Information in One Place
Good air balance reports gather all the right information in a single location. In its basic format, a residential air balance report includes:
- Project information (customer name, address, test date, and balancer’s name)
- Equipment information (manufacturer, model, and serial numbers, technical specifications)
- System information (location, room names, grille information, and design airflows)
- Test results (static pressure, fan airflow, temperature, voltage, amperage, outside air, supply register airflows, and return grille airflows).
Experienced balancers fill out all the known system information at the office. The only thing they need to do once they arrive at the job site is gather missing information. Then it’s time to measure with the appropriate test instruments.
A Residential Air Balance Report Guides Adjustments and Repairs
Once a balancer has all the measurements and information they need to complete the report, they see a clear picture of how the system operates. They compare their measured test results against manufacturer specifications. These include required airflow, rated external static pressure, and design calculations, such as room airflow from a load calculation.
Balancers examine test results to see where the system is and then figure out where to adjust. The measurements help take them towards their next steps. Such measurements are like a GPS. They guide you to necessary adjustments and issues. However, if you don’t listen to the directions or look at the display, you’ll end up lost.
Let’s say a balancer tests and determines that fan airflow is too high. From this information, they know to adjust the fan speed to get within 10% of the required airflow. Measuring individual room airflow works the same way. The results from a balancing hood may show that some rooms have too much airflow, while others don’t have enough. The measurements guide the balancer to necessary damper adjustments to get register and grille airflow within 10% of the design.
Once the balancer makes final adjustments, he or she tightens all balancing damper handles and marks them with a felt-pen marker or a shot of spray paint. This step may sound excessive, but it kept me from rebalancing an entire system years ago.
Don’t Fake the Numbers
There are times your readings won’t come out perfect. Welcome to the world of field measurements! Your readings probably won’t add up, either. It’s rare that they do. There are lots of reasons readings don’t come out perfect. Some common culprits are duct leakage, test instrument accuracy, and measurement techniques. That’s the reality of measuring in an imperfect environment.
If the readings are off substantially, you’re in luck. The best lessons you learn are when your readings don’t look right. You must dig deeper and find out why. If this happens to you, whatever you do, don’t fudge the test results. Reckon with the numbers and look deeper to understand what they reveal. This challenge will rapidly improve your testing skills.
It’s hard to fake the numbers. Any skilled HVAC professional can pick apart a bogus balance report in less than five minutes. Those who measure can see airside relationships that you can’t fake on paper. To the trained eye, they stand out like a zit on a teenager’s forehead.
Continued Report Benefits
Repeating issues that appear in the test results show improvement opportunities for your installation crews. The report makes the results of their work visible. Your top duct guys get validation for their work. The sloppy duct guys can’t hide from the report results. Minor details have an enormous impact. Issues like excess flex duct core and kinked ducts show up in the numbers.
There are also times when the system has been in operation for a while and someone comes along and damages the ducts. The report provides a paper trail documenting any future change in the system and what led to the cause.
The same accountability also protects your installation in case comfort issues arise that are beyond the HVAC system. It eliminates the HVAC system as a potential suspect and points toward other problems that can affect comfort such as building and insulation defects. The documentation takes the monkey off your back and guides you to a solution for the homeowner.
So how do you promote an air balance report as part of your work?
- First, you need to know how to air balance a duct system, and you need to have the proper test instruments.
- Second, test your work to identify areas of improvement and then make necessary corrections.
- Third, make air balancing a premium package option for your customers who want an exceptional duct system and proven results. You provide the option. They decide if they want it or not.
An air balance report helps you stand out and says volumes about your company, design methods, installations, and results. It shows confidence and proves you take responsibility for your work. Remember, if you don’t measure, you don’t know. However, your customers will. They will feel it, and your balancing report will prove it.