Air Duct Cleaning Glossary

This quick glossary decodes the 12 most important air-duct and HVAC terms every Cohasset homeowner should know before winter arrives. Clear definitions help you spot trouble early, save on repairs, and breathe easier all season long.

Winter winds off Nantasket Beach can push dust, pollen, and hidden allergens straight through your ductwork. Before the first Nor’easter hits, take 60 seconds to learn these terms so you can decide if a deep clean or seasonal tune-up is right for your Cohasset home. We serve all South Shore towns from Scituate to Plymouth—see our full service area.

SEER rating

SEER stands for Seasonal Energy Efficiency Ratio. It measures how efficiently your air-conditioner or heat pump cools your home over an entire season. A higher SEER (16+) means lower electric bills and a gentler impact on the Cape Cod grid. If your unit is older than 10 years, a new system with a SEER 20+ can cut summer costs by 30 %.

AFUE

AFUE, or Annual Fuel Utilization Efficiency, tells you how much of the fuel burned by your furnace actually heats your Cohasset home. An AFUE of 90 % means 90 cents of every dollar goes to warmth, not up the chimney. Older furnaces often dip below 70 %, so upgrading can pay for itself in two to three winters.

Heat pump

A heat pump is an all-in-one heating and cooling system that moves heat instead of burning fuel. In winter it pulls warmth from outside air (even when it’s 20 °F on Jerusalem Road) and delivers it inside. In summer it reverses and acts like an air-conditioner. Modern cold-climate models keep working down to –15 °F.

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. If you hear loud banging from your basement or closet, the blower wheel inside may be out of balance and should be inspected before winter.

Condenser

The condenser is the outdoor unit of your heat pump or central AC. It releases heat absorbed from inside your Cohasset home into the outside air. Keep it clear of seaweed and salt spray from the harbor; a blocked condenser can raise your electric bill by 15 % and shorten equipment life.

Evaporator coil

The evaporator coil sits inside the air handler and absorbs heat from your home’s air. Over time, dust and mold can coat the coil, reducing efficiency and spreading spores. A coil cleaning every 2–3 years keeps your system running at peak SEER and AFUE.

Refrigerant

Refrigerant is the fluid that absorbs and releases heat as it circulates through your heat pump or AC system. Low refrigerant means your system runs longer and never quite reaches the thermostat setting. If your Cohasset home feels clammy or the coils freeze, call us for a refrigerant check before the first frost.

BTU

BTU stands for British Thermal Unit and measures heating or cooling power. One BTU is the energy needed to raise one pound of water by one degree Fahrenheit. A typical 2,000 sq ft Cohasset home needs about 60,000 BTUs to stay cozy on a 10 °F January night.

Ductwork

Ductwork is the network of metal, fiberglass, or flexible tubes that carry heated or cooled air from your furnace or heat pump to every room. Leaky or dirty ducts in an older Cohasset home can lose 20–30 % of conditioned air, driving up bills and spreading dust. A duct inspection and seal before winter can cut heating costs by hundreds.

Zoning

Zoning divides your home into separate temperature zones controlled by dampers in the ductwork. Bedrooms on the second floor can run cooler than the living room on the first floor without wasting energy. Installing a zoning system in a Cohasset colonial with hot/cold spots can save up to 35 % on annual HVAC costs.

MERV rating

MERV stands for Minimum Efficiency Reporting Value and rates how well an air filter traps particles. A MERV 8 filter catches dust and pollen; a MERV 13 also stops mold spores and pet dander. In coastal Cohasset, where salt and seaweed blow in, upgrading to MERV 11–13 keeps indoor air cleaner and reduces duct buildup.

Load calculation (Manual J)

Manual J is the industry-standard formula HVAC pros use to size a new heating or cooling system for your exact home. It factors in square footage, insulation, window area, and Cohasset’s coastal climate. Installing an oversized unit causes short cycling and humidity problems; an undersized unit never meets demand. Always insist on a Manual J before any new installation.

Thermostat setback

Thermostat setback is the practice of lowering the temperature automatically when you’re asleep or away. A programmable or smart thermostat can drop the setting 7–10 °F for 8 hours and save 10 % on heating bills. In a drafty Cohasset Victorian, pair setback with duct sealing to prevent cold-air surprises.

Short cycling

Short cycling happens when your furnace or heat pump turns on and off too frequently, never reaching the thermostat’s set temperature. Causes include a dirty air filter, low refrigerant, or an oversized unit. In a tight Cohasset home, short cycling can spike electric bills and leave rooms unevenly heated. Schedule a system diagnostic to diagnose the root cause before winter.

Static pressure

Static pressure is the resistance air encounters as it moves through your ductwork and filters. High static pressure forces your blower to work harder, wastes energy, and can damage the motor. In older Cohasset homes with narrow duct runs, a pressure test can reveal hidden airflow problems before the first cold snap.

HEPA filtration

HEPA stands for High-Efficiency Particulate Air. A true HEPA filter captures 99.97 % of particles as small as 0.3 microns—including viruses and fine sea-salt aerosols common along the South Shore. Installing a whole-house HEPA filter or portable unit can dramatically reduce allergy and asthma triggers in a coastal home.

Frequently Asked Questions