Air Duct Cleaning Glossary

This glossary decodes the 15 most important air-duct terms Andover homeowners need to know before scheduling a premium white-glove cleaning. Learn what each term really means so you can protect your family’s air quality, cut energy waste, and keep your HVAC system running like new.

Andover’s hot, humid summers and snowy winters push ductwork harder than most, so knowing the right terms helps you choose the best white-glove service and ask the right questions. Whether you live near Ballardvale, Shawsheen Village, or right here in town, this plain-English glossary explains what matters most. Ready to breathe easier? Contact us for a free estimate.

SEER rating

SEER stands for Seasonal Energy Efficiency Ratio. It measures how efficiently a central air-conditioner cools your Andover home over an entire season. The higher the SEER number (minimum 14 in new units), the less electricity it uses and the lower your summer bills. Think of it as miles-per-gallon for your AC. Upgrading to a SEER-21 unit can cut cooling costs by 30 %.

AFUE

AFUE, or Annual Fuel Utilization Efficiency, tells you how much of the fuel burned in your furnace actually heats your Andover home instead of going up the chimney. A 95 AFUE furnace turns 95 % of its fuel into heat; the other 5 % is lost. New federal standards now require at least 90 AFUE for most gas furnaces. Upgrading can slash winter heating bills and improve comfort.

Heat pump

A heat pump is an all-in-one heating and cooling system that moves heat rather than creating it. In summer it pulls heat out of your Andover home; in winter it pulls heat from the outdoor air (even when it’s below freezing). Modern cold-climate models keep working reliably down to 5 °F. Because they don’t burn fuel, they’re far more efficient than furnaces in moderate weather.

Air handler

The air handler is the indoor “blower” that pushes conditioned air through your ductwork. It houses the evaporator coil, blower motor, and air filter. If your Andover home has a heat pump or central AC, the air handler is the quiet workhorse that keeps every room comfortable. A clean air handler prevents dust buildup that can trigger allergies and reduce efficiency.

Condenser

The condenser is the outdoor unit that releases heat extracted from your Andover home. It contains the compressor and condenser coil, which must stay free of leaves and snow to work at peak SEER. A dirty condenser can raise your cooling costs by 15 % and shorten equipment life. Keep the area around it clear and schedule a spring tune-up before Memorial Day.

Evaporator coil

Sitting inside the air handler, the evaporator coil chills refrigerant so it can absorb heat from indoor air. Over time, condensation can leave mineral deposits or mold on the coil—especially in humid Andover summers. A fouled coil forces your system to work harder, driving up bills and reducing comfort. Professional coil cleaning restores efficiency and prevents musty odors.

Refrigerant

Refrigerant is the chemical that circulates through your AC or heat pump, absorbing heat indoors and releasing it outdoors. Older R-22 (Freon) is being phased out; modern systems use R-410A or R-32. Low refrigerant means your Andover unit can’t cool properly, wastes energy, and may ice up. If your bills are climbing for no reason, a leak could be the culprit—schedule a diagnostic today.

BTU

BTU stands for British Thermal Unit and measures heating or cooling power. One BTU raises one pound of water by one degree Fahrenheit. A typical Andover furnace might deliver 60,000 BTUs, while a window AC unit could offer 10,000 BTUs. Bigger isn’t always better—an oversized unit short-cycles, wastes energy, and leaves humidity behind. A Manual J load calculation ensures the right size for your home.

Ductwork

Ductwork is the network of metal, fiberglass, or flexible tubes that carries heated or cooled air from your furnace or air handler to every room in your Andover home. Leaky, crushed, or dirty ducts can lose 20–30 % of your conditioned air before it reaches the vents. Sealing and cleaning ductwork restores airflow, improves comfort, and lowers utility bills—especially important in older homes with original ductwork.

Zoning

Zoning divides your Andover home into separate temperature zones controlled by motorized dampers and independent thermostats. Bedrooms on the second floor can stay cooler at night while the main floor stays warm, saving energy without sacrificing comfort. Zoning works best with a variable-speed air handler and can cut annual HVAC costs by 10–25 %. Ask us about adding zoning when we inspect your system.

MERV rating

MERV (Minimum Efficiency Reporting Value) rates how well an air filter traps particles. A MERV-8 filter catches dust and pollen; a MERV-13 captures viruses, smoke, and fine allergens. Higher MERV filters protect your HVAC and your family’s lungs, but they also restrict airflow if your system isn’t designed for them. In Andover’s pollen-heavy springs, upgrading to MERV-11 or MERV-13 can make a noticeable difference in indoor air quality.

Load calculation (Manual J)

Manual J is the gold-standard method for sizing HVAC equipment. It accounts for your Andover home’s square footage, insulation, window orientation, occupancy, and even local climate data. An oversized unit wastes money and comfort; an undersized one struggles on the coldest winter nights. Before you buy a new furnace or AC, insist on a Manual J calculation—we provide it free with every estimate.

Thermostat setback

Thermostat setback is the practice of automatically lowering (or raising) the temperature when you’re asleep or away to save energy. A programmable or smart thermostat can cut Andover heating and cooling costs by 10–12 % without sacrificing comfort. For best results, set a 7–10 °F setback for eight hours at night and while you’re at work. Pair it with zoning for even greater savings.

Short cycling

Short cycling happens when your Andover furnace or AC turns on and off too frequently, never reaching full capacity. It’s usually caused by a dirty air filter, low refrigerant, oversized equipment, or a faulty thermostat. Short cycling wastes energy, increases wear, and leaves humidity behind—making your home feel clammy. If your system runs for less than 10 minutes at a stretch, call us for a diagnostic before it damages the compressor.

HEPA vacuum

A HEPA vacuum uses a high-efficiency particulate air filter to trap 99.97 % of particles as small as 0.3 microns—including mold spores, pet dander, and fine dust. Our white-glove technicians use portable HEPA vacuums during duct cleaning to prevent cross-contamination in your Andover home. Unlike standard shop vacs, HEPA vacuums ensure that the contaminants we remove stay removed.

Encapsulation

Encapsulation is the process of sealing ductwork with a durable, flexible coating to stop leaks, insulate against temperature loss, and prevent mold growth. In older Andover homes with leaky or deteriorating ductwork, encapsulation restores airflow, improves efficiency, and extends system life. It’s faster and less invasive than full duct replacement and can be completed in a single day.

UV-C light

UV-C light is a germicidal wavelength that inactivates mold, bacteria, and viruses inside your ductwork and air handler. Installed alongside a new coil or in the return plenum, UV-C keeps coils clean and air cleaner without chemicals. In humid Andover summers, UV-C helps prevent musty odors and improves indoor air quality for families with allergies or asthma.

Frequently Asked Questions