Air Duct Cleaning Glossary

This no-BS glossary cracks the code on 15 air duct cleaning terms Cambridge homeowners actually need to know before calling any pro. We cut the jargon so you can spot inefficiencies, dodge costly myths, and decide when it’s time for a whole-home air duct cleaning in Cambridge.

Cambridge homes lose up to 30 % of heating and cooling through leaky or dirty ductwork—yet most owners don’t know the difference between a SEER rating and a short cycle. Before you book a duct cleaning or upgrade your HVAC, run your questions past this plain-English glossary. We’ve linked the terms that matter most to local pros you can trust. Ready to cut waste and breathe easier? Explore our full duct-cleaning services or get a free estimate today.

SEER rating

SEER stands for Seasonal Energy Efficiency Ratio. It measures how efficiently a central air conditioner cools your Cambridge home over an entire season. A higher SEER (16+ for new units) means lower electric bills and a smaller carbon footprint. If your outdoor unit is older than 10 years, odds are it’s below 13 SEER—costing you hundreds per year. Compare SEER ratings before you replace or clean your system.

AFUE

AFUE, or Annual Fuel Utilization Efficiency, tells you how much of your furnace’s fuel actually becomes heat instead of wasted exhaust. A 90 % AFUE furnace turns 90 cents of every dollar into warmth; the rest goes up the flue. Cambridge homes with AFUE below 80 % are burning cash. Upgrading to 95 % AFUE can cut winter bills by a third.

Heat pump

A heat pump is a two-way HVAC system that both heats in winter and cools in summer by moving heat instead of burning fuel. In Cambridge’s mild winters, a cold-climate heat pump can keep you comfortable down to 5 °F without backup heat. Look for models with at least 10 HSPF (heating) and 16 SEER (cooling) for year-round savings.

Air handler

The air handler is the indoor unit that pushes conditioned air through your ductwork. It houses the blower fan, evaporator coil, and air filter. If your handler is dirty or the blower wheel is gummed up, airflow drops and your Cambridge home feels stuffy even when the AC is running. Check your blower and coils before assuming ducts are the problem.

Condenser

The condenser is the outdoor metal box that releases heat from your air-conditioning cycle. In Cambridge summers, a condenser caked with pollen or shaded by ivy can lose 15 % efficiency. Keep it clear of bushes and hose it down twice a year to avoid costly repairs.

Evaporator coil

The evaporator coil sits inside your air handler and absorbs heat from indoor air, turning refrigerant into cool gas. Over time, dust and mold coat the coil, choking airflow and breeding bacteria. A dirty coil can add $200–$400 to your annual cooling bill. Learn the signs you need a coil cleaning.

Refrigerant

Refrigerant is the chemical that absorbs and releases heat as it circulates through your AC system. Low refrigerant (often from leaks) forces the compressor to work harder, driving up bills and shortening equipment life. Cambridge homeowners should never top off refrigerant themselves—only EPA-certified techs can handle it.

BTU

BTU stands for British Thermal Unit and measures heating or cooling power. A typical Cambridge furnace delivers 60,000–100,000 BTUs; a window AC unit might offer 8,000 BTUs. Matching BTU to your home’s size prevents short cycling and sky-high bills. Use a Manual J load calculation to size your system right.

Ductwork

Ductwork is the network of metal, fiberglass, or flex pipes that carry heated or cooled air from your HVAC system to every room. Leaky or crushed ducts in Cambridge’s older triple-deckers can lose 20–30 % of conditioned air before it reaches your vents. Sealing and cleaning ducts can cut heating and cooling costs by hundreds per year.

Zoning

Zoning divides your home into separate temperature zones controlled by dampers in the ductwork. In a Cambridge Victorian with hot upstairs rooms and chilly first-floor kitchens, zoning can save 30 % on energy by only conditioning occupied spaces. Installing zoning in a 3,000 sq ft home typically costs $2,500–$4,500.

MERV rating

MERV (Minimum Efficiency Reporting Value) rates how well an air filter traps particles. A MERV 8 filter catches dust and pollen; MERV 13 captures viruses and smoke. Cambridge allergy sufferers should use MERV 11–13, but check your system’s max—higher MERV can starve airflow if your blower isn’t strong enough.

Load calculation (Manual J)

Manual J is the gold-standard method for sizing HVAC systems based on your home’s square footage, insulation, windows, and Cambridge-specific climate data. Guessing or using rule-of-thumb leads to oversized units that short cycle and undersized units that run constantly. Always insist on a Manual J before any replacement.

Thermostat setback

Thermostat setback is automatically lowering the temperature when you’re asleep or away to save energy. A smart thermostat in a Cambridge triple-decker can cut winter heating bills by 10–12 % with an 8-hour nightly setback of 7–10 °F. Programmable models pay for themselves in under two years.

Short cycling

Short cycling is when your HVAC turns on and off too frequently—often in less than 10 minutes. In Cambridge homes, short cycling is usually caused by a dirty air filter, low refrigerant, or an oversized unit. Each cycle wastes energy and strains components, shortening system life by years. Spot the signs early.

Plenum

The plenum is the large box that connects your HVAC system to the main supply and return ducts. In Cambridge multi-family homes, a leaky plenum can pull unconditioned attic air into the system, making rooms stuffy and driving up bills. Inspect plenum seals whenever you schedule duct cleaning.

Damper

A damper is a movable plate inside ductwork that opens or closes to control airflow to specific rooms. Manual dampers let you balance temperatures; motorized dampers enable zoning. In older Cambridge homes, stuck or missing dampers often cause hot/cold spots that feel like duct problems.

VOCs

VOCs (volatile organic compounds) are gases emitted from paints, cleaners, and furniture that can linger in ductwork. Cambridge apartments with recent renovations often trap high VOC levels. A professional duct cleaning can remove settled particles and improve indoor air quality by up to 40 %.

Frequently Asked Questions