Air Duct Cleaning Glossary

This glossary decodes the jargon you’ll hear when researching air duct cleaning for your Georgetown home—especially important for older brick and masonry houses where dust, pollen, and hidden moisture can silently cut efficiency and air quality. Know these terms to make smarter choices when you schedule your duct cleaning.

Georgetown’s historic homes and newer builds alike depend on clean, efficient ductwork to keep energy bills low and indoor air healthy. Whether you’re comparing duct cleaning services or troubleshooting uneven heating in your 1840s farmhouse, understanding these terms helps you ask the right questions. We’ve tailored this glossary to the quirks of older masonry homes—think brick chimneys, plaster walls, and seasonal humidity swings that can shorten HVAC life if ignored. Need a free estimate? Contact us today.

SEER rating

SEER stands for Seasonal Energy Efficiency Ratio. It measures how efficiently an air conditioner or heat pump cools your home over an entire season, calculated by dividing cooling output in BTUs by the energy it consumes in watt-hours. A higher SEER (16 or above) means lower monthly bills and a gentler load on Georgetown’s older ductwork, which can crack under pressure. Look for ENERGY STAR models if you’re upgrading in a home with original plaster and tight crawl spaces. See our full list of services.

AFUE

AFUE, or Annual Fuel Utilization Efficiency, tells you how much of the fuel burned by your furnace actually becomes heat for your home. Expressed as a percentage, a 90 AFUE furnace turns 90% of its fuel into warmth, while the rest escapes as exhaust. In Georgetown’s drafty older homes, upgrading to a high-AFUE model can offset heat loss through single-pane windows and uninsulated brick walls. Learn more at request a free estimate / contact us.

Heat pump

A heat pump is a two-way HVAC system that moves heat in or out of your home using refrigerant and a reversing valve. In summer it acts like an air conditioner; in winter it extracts heat from cold outdoor air to warm your house. Because it doesn’t burn fuel, it’s quieter and often cheaper to run than a traditional furnace—ideal for Georgetown homes with limited attic space for ductwork expansion.

Air handler

The air handler is the indoor unit that circulates conditioned air through your ductwork. It houses the blower fan, evaporator coil, and air filter, and often connects to a heat pump or furnace. In older Georgetown homes with original ductwork, a mismatched or undersized air handler can overwork your system and stir up dust from cracked masonry joints—leading to costly repairs if left unchecked.

Condenser

The condenser is the outdoor unit of an air conditioning or heat pump system. It releases heat absorbed from inside your home into the outside air using refrigerant and a compressor. Positioned on the north side of your house in Georgetown’s humid summers, a shaded condenser runs more efficiently and lasts longer—so keep it clear of ivy and brick dust.

Evaporator coil

The evaporator coil sits inside the air handler and absorbs heat from indoor air as refrigerant passes through it. Over time, mold and dust can build up on the coil, reducing cooling efficiency and spreading allergens through your ductwork. In Georgetown’s older homes with plaster walls and limited airflow, a dirty coil can double your energy bills in just one season.

Refrigerant

Refrigerant is the chemical compound that absorbs and releases heat as it cycles between the evaporator and condenser coils. Older systems may use R-22 (Freon), which is being phased out due to environmental concerns, while newer systems use R-410A or R-32. If your Georgetown home still has an R-22 system, consider upgrading to avoid costly refrigerant shortages and improve indoor air quality.

BTU

BTU stands for British Thermal Unit, the standard measure of heat energy. One BTU is the amount of heat needed to raise the temperature of one pound of water by one degree Fahrenheit. Furnaces and air conditioners are rated in BTUs per hour; a 60,000 BTU furnace can heat a 2,000-square-foot Georgetown home, but only if your ductwork and insulation match the load—otherwise you’re paying to heat the great outdoors.

Ductwork

Ductwork is the network of metal, fiberglass, or flexible tubes that carry heated or cooled air from your HVAC system to every room. In Georgetown’s older homes, original ductwork may be made of uninsulated metal or even clay tiles, prone to leaks, rust, and mold growth. Leaky ducts can lose up to 30% of conditioned air, driving up bills and pulling in attic dust through cracked plaster ceilings.

Zoning

Zoning divides your home into separate temperature-controlled areas using motorized dampers in the ductwork and multiple thermostats. It’s ideal for Georgetown’s two-story homes with sun-exposed west-facing rooms or finished attics, where one thermostat can’t keep all floors comfortable. Proper zoning reduces energy waste and prevents overworking your HVAC in rooms that rarely get used.

MERV rating

MERV stands for Minimum Efficiency Reporting Value, a scale from 1 to 16 that rates how well an air filter captures particles. A MERV 8 filter traps dust mites and pollen; a MERV 13 captures viruses and smoke. In Georgetown’s older homes with brick chimneys and open fireplaces, upgrading to a MERV 11–13 filter can dramatically reduce soot and ash recirculation through your ductwork.

Load calculation (Manual J)

Manual J is the industry-standard method for calculating how much heating and cooling your home needs based on size, insulation, windows, and local climate. A Georgetown home with single-pane windows, plaster walls, and a finished attic will have a very different load than a newer ranch with double-pane windows. Skipping this step can lead to an oversized or undersized system that wastes energy and strains your ductwork.

Thermostat setback

Thermostat setback is the practice of lowering (in winter) or raising (in summer) the temperature when you’re asleep or away to save energy. Programmable or smart thermostats make this automatic. In Georgetown’s drafty older homes, even a 7-degree setback overnight can cut heating bills by 10% without sacrificing comfort—just ensure your ductwork isn’t leaking at the joints.

Short cycling

Short cycling happens when your HVAC system turns on and off too frequently, usually because it’s oversized for your home or your ductwork is leaking. In Georgetown’s older masonry homes, short cycling can overheat the furnace, damage the heat exchanger, and stir up dust from cracked plaster and brickwork. It also drives up energy bills and reduces system lifespan.

Plenum

The plenum is the large metal box or duct section that connects your HVAC system to the main supply and return ducts. In older Georgetown homes, the plenum may be a repurposed brick chamber or a poorly sealed metal box prone to air leaks. A leaky plenum can pull in attic dust and unconditioned air, reducing efficiency and spreading allergens throughout your home.

Duct liner

Duct liner is a fiberglass or foam insulation applied inside metal ductwork to reduce heat loss, noise, and condensation. In Georgetown’s older homes with uninsulated metal ducts, adding or replacing duct liner can prevent mold growth from summer humidity and reduce energy waste—especially in attics and crawl spaces where temperatures swing wildly.

Frequently Asked Questions