System performance testing should be something all stakeholders within the HVAC and energy efficiency industries should embrace. It cuts to the chase as to whether a system is delivering the comfort and energy efficiency it promises.
One of the biggest challenges? People cannot understand “System Performance” without agreeing on the definition of an HVAC system. For decades our industry has referred to unitary equipment as the “system.” Think about our industry’s marketing over the past 30-40 years. In most cases, manufacturer literature refers to furnaces and condensing units as “systems.”
Contractors perpetuated this misnomer with marketing showcasing replacement “systems.” In truth, our industry has been marketing and selling replacement equipment, not systems.
While technically an air handler/furnace, coil, and condensing unit are a closed loop system when it comes to the refrigerant side, they are far from being the SYSTEM when it comes to the “Air” side of comfort delivery.
An HVAC system starts at the return grilles, which are connected by ductwork to the return side of the FURNACE OR AIR HANDLER, which in turn is connected to the supply ductwork, and ultimately the supply registers.
An HVAC “SYSTEM” starts at the return grilles. They are connected by ductwork to the return side of the furnace or air handler. These are connected to the supply ductwork, and ultimately the supply registers.
Once all stakeholders begin to understand that while the equipment is a component of an HVAC system — in fact, you could say it’s the heart and lungs of the system — it still is not “the” system.
This sounds logical and even simplistic, but it’s an important concept that needs to resonate not just with manufacturers and distributors, but with utilities and government who design energy programs and efficiency standards.
Still, today most programs and standards are focused on equipment efficiencies and duct sealing measures that miss the mark. They should focus on field measured system efficiencies.
Why Do Manufacturers Insist the System is the Equipment?
Manufacturers are rightfully concerned that if standards are written to govern how to measure field performance of an entire “system,” government agencies will hold them accountable for something completely beyond their control.
The fear is these agencies might expect manufacturers to design equipment that overcomes the deficiencies of a poor air distribution and magically deliver 100% of its capacity to the space.
So let’s put that into perspective. Imagine if EPA (Environmental Protection Agency) held auto manufacturers accountable for the MPG (miles per gallon) of a vehicle in which the engine was being replaced, regardless of the condition of the car?
In a comparable situation to the replacement sector of the HVAC industry, an auto manufacturer would be held accountable for the MPG of a vehicle with a leaky gas tank, shot transmission, and bald tires, because a brand-new engine was installed in that jalopy. That would be ludicrous, right? How could the DOE (Department of Energy) hold manufacturers accountable for the installed efficiency of an HVAC system? The furnaces, coils, air handlers and condensing units are just components, not the system itself.
It’s important for manufacturers and distributors to educate government and utilities about this indisputable reality. Expecting anything different defies the very laws of physics.