A high-efficiency heating and cooling system may not be something a custom luxury homeowner prioritizes when designing their home. However, a well-designed HVAC system can improve your family’s health and comfort and save you energy and money.

What is a High-Efficiency HVAC System?

Many home builders don’t use a closed return system. Instead, they build in the space between a home’s drywall where the air passes through dust, debris, and other irritants. Those dirty particles end up circulating through the home through the ducts.

The key to a high-efficiency HVAC system is using a closed return system. The air flows into a home’s rooms and back into the central system through a closed, fully ducted system sealed with sheet metal.

By using this closed return system, high-efficiency HVAC systems keep more irritants out and more clean air in. 

How Much Energy Will a High-Efficiency HVAC System Save?

A high-efficiency heating and cooling system will only realize its potential in a home that’s detailed to require less heating and cooling than the typical home. This means sealing all duct seams, eliminating gaps around insulation batts, and plugging air leaks, especially in attics and basements. The small investment required for these measures will not only lower energy bills but also make the home healthier and more comfortable. 

High-efficiency systems use up to one-third less energy. If you have an older system installed in the past 20 to 25 years, you might have a furnace with a 65 to 70% Annual Fuel Utilization Efficiency (AFUE) rating. Newer high-efficiency models can work at a 93% AFUE rating and provide you with better airflow.

How Much Money Can a High-Efficiency System Save?

If you have an older system with a low AFUE rating, one-third of every energy dollar you spend is being wasted. 

Upgrading to a high-efficiency system with an AFUE rating of 90% or higher can save you up to 20% of every energy dollar spent.

The average annual energy cost for a home equipped with a gas furnace and central air (old HVAC system) is about $875, which is 43% of a year’s total energy spending. An average new HVAC system with ductwork in the US costs $9,582. That means after installing a high-efficiency system with an AFUE rating of 90% or higher, the system will pay for itself after only a few years.

Other cost-saving benefits to high-efficiency HVAC systems include tax rebates and discounts on energy-efficient usage.


With over 25 years of building experience, Donnelly Timmons builds luxury custom homes with high air quality in mind. We can provide you with a high-efficiency HVAC system in a new custom home in the Nashville area. 

To learn more and get a free consultation, contact Donnelly Timmons!