HVAC Energy Efficiency for Durham Homeowners
Where Energy Goes in a Durham Home
In most Durham-area homes, HVAC accounts for 40–60% of total energy use. The specific split between heating and cooling depends on the home’s size, insulation level, and system type. In older homes with poor insulation and leaky ductwork, that percentage is higher.
The most cost-effective efficiency improvements, in rough order:
- Duct sealing — leaky ducts in unconditioned spaces (attics, crawl spaces) can lose 20–30% of conditioned air before it reaches the living space
- Thermostat management — a programmable or smart thermostat reduces cooling and heating in unoccupied periods; 2-4°F setback can reduce energy use 10–15%
- Equipment maintenance — a poorly maintained system uses more energy per BTU of delivered comfort; refrigerant issues and dirty coils both reduce efficiency
- Insulation improvement — air sealing and insulation in the attic reduces cooling load in summer and heating load in winter
- Equipment replacement — upgrading from a low-SEER system to a current-standard unit; the payback period depends on equipment age and current efficiency
Equipment Efficiency Ratings
For air conditioning and heat pumps, SEER2 (Seasonal Energy Efficiency Ratio 2) is the current standard rating. Higher numbers mean more cooling per unit of electricity. In Durham’s climate, the payback period on higher-SEER equipment is shorter than national averages because cooling hours are higher.
For heat pumps in heating mode, HSPF2 (Heating Seasonal Performance Factor 2) rates heating efficiency. In Durham’s mild winters, heat pumps spend most of their heating-season hours in efficient operating ranges.
What to Evaluate
Duke University facilities management operates large heating and cooling infrastructure in Durham — a local benchmark for rigorous energy management. The City of Durham provides energy efficiency program information for residential customers.
After the basics, the evidence points to duct performance as the highest-impact efficiency opportunity in older Durham homes. A contractor who offers duct leakage measurement — a blower door test or duct blaster test — can quantify actual losses before recommending duct sealing.