The Hidden Cost of Poor Installation: Why HVAC System Performance Falls Short

I came across this great article from the ESCO Institute. It's definitely worth a read. 👇

Despite the increasing sophistication of modern HVAC equipment, many systems installed in the field today fail to deliver their promised efficiency and performance. While manufacturers continue to innovate with advanced technologies and smarter controls, a disconnect remains between equipment potential and real-world operation. This gap is not due to flaws in the equipment itself but rather stems from critical installation and commissioning errors that are far too common.

To understand why so many HVAC systems underperform, we must look at the key factors that undermine system efficiency, reliability, and occupant comfort. Four primary culprits stand out: improper refrigerant charging, inadequate airflow, lack of combustion safety testing, and incorrect sensible-to-latent heat ratios.

1. Improper Refrigerant Charging

Perhaps the most prevalent issue in the field, improper refrigerant charging, affects a staggering 68% of all air conditioning systems. These systems are often charged either above or below the manufacturer's recommended levels. While the margin of error may seem minor, the consequences are anything but. Even a slight deviation from the ideal charge can increase energy consumption by 18% to 25%.

An overcharged system can lead to high compressor head pressures, increased wear and tear, and ultimately a shorter lifespan for the equipment. Conversely, undercharged systems struggle to provide adequate cooling, increasing run times and operational costs. Both scenarios contribute to unnecessary energy waste and higher utility bills for consumers.

2. Inadequate Airflow

Another widespread issue is improper airflow, which affects 70% of HVAC systems in operation. This problem typically arises from undersized ductwork, dirty air filters, blocked vents, or poorly designed distribution systems. Airflow is the lifeblood of HVAC performance, and when it falls outside optimal parameters, system efficiency and comfort suffer.

Inadequate airflow compromises both sensible and latent capacity. On the sensible side, it leads to uneven temperatures and reduced cooling or heating output. On the latent side, it hampers humidity control, creating a sticky, uncomfortable indoor environment that can encourage mold growth and degrade indoor air quality. In the end, occupants are left adjusting thermostats more frequently, leading to further energy inefficiency.

3. Lack of Combustion Safety and Efficiency Testing

Shockingly, 91% of HVAC systems that involve combustion heating go untested for combustion safety and efficiency. This oversight is not only an energy efficiency issue but also a serious safety concern. In systems burning natural gas, propane, or oil, a proper air-to-fuel ratio is crucial for clean, efficient combustion.

Deviations in this ratio can reduce energy efficiency by 18% to 20% and may also result in the production of carbon monoxide, an invisible and potentially lethal gas. Flame instability, back drafting, and other combustion issues can further exacerbate the problem, posing risks to both occupants and property. Comprehensive combustion testing ensures both optimal performance and peace of mind.

4. Incorrect Sensible-to-Latent Heat Ratios

HVAC systems are designed to manage two types of heat: sensible (temperature) and latent (moisture). Achieving the right balance between these two is essential for occupant comfort and system efficiency. Unfortunately, many systems fail to maintain this balance due to improper sizing or incorrect configuration.

When latent heat is not adequately removed, indoor humidity levels rise. This can lead to condensation on walls and windows, musty odors, and an increased risk of mold and mildew. When systems are oversized, they often short-cycle, meaning they run for brief periods and shut off before dehumidifying properly. The result is discomfort, poor indoor air quality, and increased energy use from constant cycling.

The Bottom Line: Quality Installation Matters

High-performance HVAC systems require more than just cutting-edge equipment. To truly deliver on their promise, they demand meticulous attention to installation details and rigorous performance verification. Without proper commissioning, even the most advanced systems can operate inefficiently, driving up energy costs, reducing comfort, and shortening equipment lifespan.

The good news is that these issues are preventable. With proper training, adherence to best practices, and a commitment to quality, contractors can ensure HVAC systems perform as intended. This includes verifying refrigerant charge, measuring airflow, conducting combustion safety testing, and ensuring systems are correctly sized and configured for their application.

In the HVAC industry, performance should not be left to chance. It must be measured, verified, and guaranteed. As energy costs continue to rise and consumers demand greater efficiency and comfort, prioritizing proper installation and commissioning is not just a good idea, it's essential. Investing in performance now pays dividends in the form of lower operating costs, safer indoor environments, and longer-lasting equipment.

For contractors, building professionals, and homeowners alike, the message is clear: don't let good equipment go bad through poor installation. Demand quality. Verify performance. And unlock the full potential of your HVAC system.