General HVAC Frequently Asked Questions

HVAC stands for Heating, Ventilation, and Air Conditioning.

Proper ventilation ensures the circulation of fresh air, removes pollutants, controls humidity, and maintains indoor air quality, contributing to a healthier and more comfortable environment.


It’s recommended to service your heating system annually, preferably before the colder months, to ensure efficiency, detect issues early, and prevent breakdowns.

Common signs include unusual noises, a sudden increase in energy bills, uneven heating, and frequent on/off cycling.


Proper ventilation helps regulate indoor temperature, reducing the load on heating and cooling systems and contributing to energy efficiency.

Improving ventilation can be achieved by regularly changing air filters, using exhaust fans, and considering the installation of a ventilation system like an energy recovery ventilator (ERV) or heat recovery ventilator (HRV).

Air Conditioning

Air conditioner filters should typically be replaced every 1-3 months, depending on factors like filter type, usage, and indoor air quality.

Regular maintenance includes cleaning or replacing filters, checking and cleaning coils, inspecting the refrigerant levels, and scheduling professional tune-ups.

Energy Efficiency

Upgrade to a programmable thermostat, seal air leaks, ensure proper insulation, and schedule regular maintenance to enhance energy efficiency.

Yes, many governments offer incentives, tax credits, or rebates for installing energy-efficient HVAC systems. Check with local authorities or energy efficiency programs for available incentives.


At that time, the current HVAC industry refrigerant, R-410A, was deemed a contributor to global warming and the EPA mandated that manufacturers switch to a refrigerant with a Global Warming Potential (GWP) of 700 or less by January 1, 2025.

In 2020, as part of a global agreement to reduce greenhouse gasses, the American Innovation and Manufacturing (AIM) Act gave the US Environmental Protection Agency (EPA) authority to regulate hydrofluorocarbons (HFCs) and begin the phase down of refrigerants with high HFCs by 2036.

When selecting our new refrigerant, Lennox considered ease of installation, service, safety, performance, environmental impact and more. We chose our 2025 Compliant Refrigerant for a number of reasons:

  • The GWP is 78% lower than previous refrigerants and has zero ozone depletion potential.
  • Lennox engineers worked to maximize equipment performance and efficiency with this refrigerant while minimizing changes to installation requirements.
  • Our testing shows it remains more consistent in long-line sets for more reliable performance.

Transitioning to Low GWP Refrigerants

GWP is a way to measure the gases going into the atmosphere and their effect on our planet’s temperature. Low GWP indicates a safer gas for the environment. Lennox’ 2025 Compliant Refrigerant choice has 78% lower GWP than the previous version.

Refrigerants with low GWP are designed to minimize impact on the environment in terms of global warming and climate change. Several factors contribute to refrigerants having low GWP:

  • Ozone-Depleting Free: Compared to refrigerants with high levels of HFCs, low GWP refrigerants are non-ozone depleting and have lower global warming potential.
  • Chemical Composition: Low GWP refrigerants are composed of elements and compounds that have minimal greenhouse gas effects, such as hydrogen, carbon, and fluorine. Refrigerants with high GWP often contain chlorine.
  • Short Atmospheric Lifetime: Refrigerants with shorter atmospheric lifetimes tend to have a lower GWP level as they don’t stay in the atmosphere for extended periods, reducing the overall impact on global warming.


Lennox has chosen to replace R-410A, with our 2025 Compliant Refrigerant, R-454B. It has 78% lower GWP than previous refrigerants, has shown to be more consistent in long-line sets during testing, and will benefit equipment performance with minimum changes to installation requirements.

The last refrigerant transition phased out refrigerants with high ozone depletion potential (ODP), such as R-22. The current HVAC industry refrigerant, R-410A, does not contribute to ozone layer depletion but it does have significant Global Warming Potential (GWP) as high as 2088. The Environmental Protection Agency (EPA) mandated that manufacturers switch to a refrigerant with a GWP of 700 or less by January 1, 2025.

The Environmental Protection Agency (EPA) recently proposed regulations aimed at banning the use of many hydrofluorocarbons (HFCs) in HVAC systems. Beginning in 2024, the phase down of HFCs are required to be at 40% below baseline, a significant decrease in the number of available production and consumption allowances compared to previous years.

The HFCs and HFC-blend refrigerants being phased out are as follows:

  • R-404A
  • R-134A
  • R-410A
  • R-407C used to replace R-22.

In response to the new regulations, low-GWP refrigerants have been created to have similar but better efficiencies and capacities than the refrigerants they are intended to replace. These include R-32 and R-454B.

IAQ Market Trends

Demand for Healthier Air is Growing

Homeowners are willing to spend an average of $800 on Indoor Air Quality (IAQ), a 25% increase from 2019.* HVAC systems are intertwined with IAQ as they address temperature control, outdoor air ventilation, filtration, pressurization, and moisture control, allowing you to earn profits by adding Lennox Healthy Climate™ IAQ accessories to every install.

Homeowner IAQ Trends
  • 57% of homeowners rate IAQ just as important as energy efficiency
  • 57% of customers want to learn more about IAQ
  • 46% of homeowners want whole home solutions

American Home Comfort Study 2022 by Decision Analyst

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