A New Dimension in Service Agreements

Sept. 7, 2011
Traditional service agreements are focused on the performance of the equipment part of an HVAC system as though the equipment was the single component that controlled efficiency and comfort.

Traditional service agreements are focused on the performance of the equipment part of an HVAC system as though the equipment was the single component that controlled efficiency and comfort. Why not take a look at the performance of other components of the system and consider how you could move ahead of the rest of the industry if you were to look beyond the box, and offer a higher level of system operating efficiency?

The Dilemma

Many contractors are being faced with a new dilemma. As SEER numbers skyrocket and new equipment is sold with a promise of more energy savings and more comfort, consumers are not seeing the savings or the comfort they were sold.

A traditional service call is dispatched only to find the manufacturer recommended service checklist finds no fault with the equipment. Your customer demands answers, but you may have none to offer.

The Solution

The answers to these comfort and efficiency questions are found only by looking beyond the box with a new set of service parameters that will open the doors to solutions that your company may have overlooked for decades.

Consider expanding your service agreements beyond the box, and focus on the performance of the system by including the effects of the duct system. Adding a couple of quick tests is sure to add a new dimension to diagnostics and troubleshooting.

Once system performance issues are identified, new repairs can be offered to your customers that will solve their comfort and efficiency problems and generate new business for you. Both parties win at this new facet of our industry.

New Temperature Measurements

Traditional service agreements include temperature measurement of air entering and exiting the equipment. This equipment temperature change measurement, when linked to airflow, can provide evidence that the equipment is operating within specifications, but that doesn’t tell the whole story.

By adding temperature measurement at the registers and grilles, system temperature measurement can be seen. Rarely is system temperature change the same as equipment temperature change.


Say the equipment temperature change in cooling mode is 20 degrees. In many regions of the country, if airflow is adjusted properly, that indicates the equipment is operating well.

But if the system temperature change of the system is measured at one or two registers and grilles is only 12 degrees, a new performance issue has been discovered outside the box.

Divide 12F by 20F to discover only 60% of the equipment generated BTUs are being delivered into the conditioned space of the building. Eight degrees or 40% of the cooling capacity of the equipment was lost through the duct system as the conditioned air traveled through unconditioned space.

Consider adding register and grille temperature to your service agreements as an additional service to your customers. This will uncover temperature loss issues that you can address for the customer.

The Value of the Repairs

Reducing duct leakage and installing additional duct insulation are the most common fixes needed once these system defects are identified. Are these repairs profitable? It depends on how you choose to price them. Price these repairs not at usual markups, but sell these repairs for what they are worth.

Compare the value of a 40% increase in efficiency to what the marked up cost of 40% more efficient cooling equipment might cost, if you can find equipment that’s much more efficient. Would that value be perhaps $500 per ton? Or is it $750 per ton? Remember the traditional cost, plus markup doesn’t apply here. You’re selling solutions, not just labor and material.

Total External Static Pressure

The other obvious measurement that can be added to your service agreements to expand your service beyond the box is to measure total external static pressure. This test takes less than 5 minutes yet provides amazing insight into the sizing and installation quality of your air distribution system, the pressure drop of your filter and the condition of the cooling coil.


Take the pressure reading where air enters the air moving equipment and where air exits the air moving equipment using a manometer and some tubing to connect the manometer to the equipment. Drill 3/8-in. test holes right into the equipment to get access to the pressures.

Say the fan is rated at .50-in. w.c. of pressure as indicated on the nameplate. If the reading where air enters the equipment is -.40-in. w.c., and the pressure at the discharge of the equipment is +.42-in. w.c., simply add the two readings together to find the system is operating at .82-in. w.c., which is actually the national average for a .50-in. w.c. rated fan. Yes, the system is in trouble and airflow is probably well below 300 CFM per ton.

Pressure Repairs

Typical pressure repairs include a new filtration system, custom designed with a low pressure drop, cleaning cooling coils and most often adding additional duct capacity to undersized duct systems. The typical U.S. residential duct system is 25% undersized. Once again price the repairs based on the potential improvement in system performance compared to the cost of more efficient equipment.

Offer Additional Testing

More and more successful contractors are learning and utilizing advanced system performance diagnostic testing. While temperature and pressure testing may indicate system defects, most likely more advanced airflow, pressure and temperature testing may be needed to pinpoint and solve system performance defects.

This is a valuable service that your customers will appreciate and quickly understand the need to purchase, once they are taught to see beyond equipment performance alone.

Consider expanding your service agreements to go beyond the box and provide advanced services that will distinguish you from the pack of competitors and open up needed and profitable new services you can offer those you serve.

Rob “Doc” Falke serves the industry as president of National Comfort Institute an HVAC based training company with technical and business level membership organizations. If you're an HVAC contractor or technician interested in free reports on how to measure and interpret static pressure or system temperature change, 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.