One of our NCI instructors was training in the field last week when a student learned how he could measure total external static pressure and plot fan airflow in just a few minutes. The student was delighted with his newly acquired skill, but questioned the method their energy rater had used where a duct leakage fan was used to determine equipment fan airflow.
After discussing how plotting fan airflow could complete the task in five minutes compared to a half hour for the other option, the company owner commented; “This is HVAC work, not a science project.” The class agreed testing is essential to verify good performance has been delivered, but also that if it can be quick and simple they will be far more willing to include it in each service call and equipment startup during their fast paced day.
Efficiency is Invisible
We all love to finish up a job, step back and be pleased with our work, right? However, a good-looking system doth not efficiency make. Although a nice looking system is a reward in itself and it’s good for business.
The idea that quality can be assured by completing endless inspection checklists has been tried in many utility programs and is falling short of meeting the efficiency that was promised.
Efficiency has to be measured before any assurance can be given to your customers.
The best place to start is by measuring a system’s performance and comparing the measured values against the manufacturer’s specifications.
If airflow is specified at 1200 CFM, measure it. If airflow tests out at 727 CFM, the system doesn’t meet manufacturer’s specification and the performance isn’t going to materialize. If you measure airflow at 1165, you’ve met the spec. Way to go. Once again, since airflow is invisible, you need to measure to know its outcome. You can inspect it all day long and still be guessing at the results.
Let’s talk electrical. If the manufacturer’s specifications require 240 volts, you measure it, don’t you? 238 volts is fine. 187 volts and you’re in trouble, right? Like airflow, it’s doubtful if anyone feels it with their hands or inspects electrical to prove it works. Electricity and its properties are invisible too, but as an industry, electrical testing is commonly accepted. Everyone understands the principle of testing.
What Evidence Do Your Customer’s Want?
While every customer is different and has a wide variety of expectations when it comes to efficiency and performance, your job is to establish a recognized and repeatable program in your company to provide a reasonable assurance that your customer will be comfortable and that utility bills will be manageable.
A reasonable program will also have options for your customers to choose from. Let’s investigate several ways to bundle testing and assurance services for your customers. We’ll follow the good, better and best tradition.
Good Testing and Assurance – Basic testing may include: measurement of equipment temperatures and comparing them to manufacturer’s specifications, verifying electrical values and testing total external static pressure and plotting fan airflow. Of course, you should measure Carbon Monoxide in heating mode if fossil fuel appliances are installed.
Package this information in a written report with the warranty information, and you’ve done better that most in the industry. This is a good start.
Better Testing and Assurance – The next step up may be to add more performance related data to prove the effectiveness of your work. Remember, this can be done in your service as well as installation departments.
Consider calculating delivered efficiency of the equipment. This isn’t has hard as you may imagine. At the equipment, use the fan airflow and temperature above to calculate equipment delivered BTU. This is calculated by multiplying airflow by temperature change, by a BTU multiplier. Compare the equipment delivered BTU to the equipment rated BTU capacity as evidence the equipment is operating according to manufacturer specifications.
You may also add some pressure drop testing of the coil and filter and compare this to the manufacturer’s specifications. Consider adding additional manufacturer specifications in your warranty package.
Best Testing and Assurance – Testing that moves past the equipment and into the distribution system is the ultimate evidence discerning customers are looking for. Full testing and assurance may include an air balance report showing that the airflow into each room meets your engineering calculations within 10%. You might add temperature testing at the registers and grilles and BTU delivery calculations into the building.
The best assurance will address evidence that each system complaint your customer had has been adequately addressed and solved. Air balance reports have been used for decades as the ultimate quality assurance document.
How Much Will Customers Pay?
Of course how much a customer is willing to pay depends on what they want and how prepared and able you are to deliver what they’re looking for.
Previously it was recommended that you establish a recognized and repeatable program in your company to provide reasonable assurances of quality and efficiency. When your company has packaged a program and is ready to deliver those services, your chances of selling testing as greater valued service increases substantially.
Experienced contractors often can add 20% to 30% of the retail price of a system upgrade as part of the package if they’re willing to test and document the results of their work. This can be a very profitable upgrade and a cost that many customers are more than willing to pay if they know they’ve received what you have promised to deliver.
Good HVAC Work, Not Science Projects
When you get down to it, this is HVAC work. Be assured however that solid business principles will always drive this industry and drive our customers. Most people want quality and are willing to pay for it. We aren’t interested in science projects and neither are our customers. What we both want is reasonable evidence that we’ve done a good job verified by simple, reasonable testing.
Rob “Doc” Falke serves the industry as president of National Comfort Institute an HVAC based training company and membership organization. If you're an HVAC contractor or technician interested in a free field procedure about how you can plot fan airflow, 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.