HVAC & Home Comfort Glossary
Plain-English definitions of the terms you'll see on this site and in your estimate.
Cooling & heating
- SEER2
- Seasonal cooling-efficiency rating (2023 standard). Higher means more cooling per dollar of electricity.
- AFUE
- Furnace efficiency — the percentage of fuel turned into usable heat.
- HSPF2
- Seasonal heating-efficiency rating for heat pumps. Higher is better.
- Heat pump
- Heats and cools by moving heat instead of burning fuel — very efficient in mild Central Texas winters.
- Ductless / mini-split
- A ductless heat pump that conditions a single room or addition — ideal for garages, offices, and casitas.
- Tonnage
- AC capacity (1 ton ≈ 12,000 BTU/hr), set by a load calculation — not square footage alone.
- Manual J
- The industry load calculation that right-sizes equipment to your specific home.
- Short cycling
- When a system turns on and off too frequently — often a sign of oversizing or a fault.
- Dual-fuel
- A heat pump paired with a gas furnace for backup — efficient most of the year, with strong heat in a hard freeze.
Refrigerants & credentials
- R-410A
- A legacy refrigerant being phased down under the EPA AIM Act.
- A2L (R-454B / R-32)
- Lower-global-warming refrigerants used in new 2025+ systems.
- EPA certified
- Federal certification required to handle refrigerants safely and legally.
- Factory-trained
- Technicians trained by the manufacturer (Holman is Trane & Daikin factory-trained) on correct sizing and installation.
Indoor air quality
- MERV
- Filter rating — a higher number captures smaller particles (balance with airflow).
- HEPA
- High-efficiency particulate filtration for the smallest airborne particles.
- UV germicidal light
- UV-C light installed at the coil to reduce mold and microbial growth.
- Whole-home dehumidifier
- Controls humidity beyond what the AC manages on its own — useful in muggy Central Texas shoulder seasons.
- ERV / HRV
- An energy- or heat-recovery ventilator that brings in fresh air without wasting conditioned air.
- Cedar fever
- The Central Texas winter allergy season driven by mountain cedar pollen — a common reason homeowners upgrade filtration.