Air Duct Cleaning Glossary

Randolph homeowners with older brick homes need a clear, no-jargon glossary to decode air-duct lingo before scheduling a clean. These terms decide comfort, cost, and indoor air quality—especially when your ducts hide historic masonry or fragile liners.

Whether your Randolph home still breathes through original brick flues or modern flex-duct, knowing the right terms saves time and money. Air Duct Cleaning services we offer are tailored for older masonry systems and newer ductwork alike. Contact us for a free estimate that speaks your home’s language.

SEER rating

SEER stands for Seasonal Energy Efficiency Ratio. It measures how efficiently a central air-conditioner cools your Randolph home over an entire season. A higher SEER (16+) means lower electric bills and a gentler load on your aging ductwork. Older systems often dip below SEER 10, so upgrading can cut runtime and dust buildup in historic masonry ducts. See our full list of services.

AFUE

AFUE is Annual Fuel Utilization Efficiency, the percentage of fuel your furnace turns into heat instead of waste. An AFUE of 90 means 90 % of gas becomes warmth; the rest escapes up the chimney or into duct leaks. In Randolph’s older homes, AFUE below 80 is common and drives up heating costs while forcing ducts to work harder. Learn more at request a free estimate / contact us.

Heat pump

A heat pump moves heat in or out of your home using refrigerant, acting as both heater and air conditioner. Unlike furnaces, it doesn’t burn fuel, so it’s quieter and cleaner for Randolph’s historic neighborhoods. Modern cold-climate models keep pumping warmth down to 5 °F, protecting older duct liners from freeze-ups and cracks.

Air handler

The air handler is the indoor unit that pushes conditioned air through your Randolph home’s ductwork. It houses the blower motor, evaporator coil, and air filter. If your home has original plaster ceilings, a properly sized air handler prevents excessive pressure that can crack fragile masonry ducts over time.

Condenser

The outdoor unit that releases heat absorbed from inside your Randolph home. It contains the compressor and condenser coil. A dirty condenser coil forces the system to run longer, blowing more dust into ducts and shortening the life of historic liners. Keep it clear of leaves and salt spray from Randolph’s coastal winds.

Evaporator coil

Located inside the air handler, the evaporator coil cools air by absorbing heat and turning refrigerant from liquid to gas. Over time, condensation can corrode older coils, especially in Randolph’s humid summers. A corroded coil drips water into ducts, fostering mold that thrives in brick flues.

Refrigerant

The chemical that absorbs and releases heat as it cycles between indoor and outdoor units. Older systems often used R-22 (Freon), now phased out and costly to recharge. Modern replacements like R-410A are safer for Randolph homes with sensitive masonry ducts and help avoid pressure spikes that crack liners.

BTU

British Thermal Unit measures heat energy. One BTU raises one pound of water by one degree Fahrenheit. A furnace rated at 60,000 BTU delivers 60,000 BTUs of heat per hour. In Randolph’s drafty Victorian homes, an undersized furnace runs constantly, overheating ducts and loosening fragile masonry mortar.

Ductwork

The network of pipes or channels that carry heated or cooled air from your HVAC system to every room. In Randolph’s older homes, ductwork may be original brick flues, fragile metal, or modern flex-duct. Leaky or collapsed sections waste energy and pull in dust that coats historic masonry with grime.

Zoning

Zoning divides your Randolph home into separate temperature areas controlled by dampers in the ductwork. Older masonry systems rarely support zoning without costly modifications. For newer ductwork, zoning saves energy by conditioning only occupied rooms, reducing wear on historic liners.

MERV rating

MERV (Minimum Efficiency Reporting Value) rates how well an air filter traps particles. A MERV 8 filter catches dust mites and pollen; MERV 13 captures viruses and fine soot from Randolph’s busy streets. Using a filter too high for your system can choke airflow and stress older duct liners.

Load calculation (Manual J)

Manual J is the industry-standard method for calculating how much heating or cooling a Randolph home needs. It factors in square footage, insulation, window orientation, and even brick thermal mass. A proper load calculation prevents oversized equipment that cycles on and off too quickly, harming fragile masonry ducts.

Thermostat setback

Setting your thermostat back (lower in winter, higher in summer) when you’re asleep or away saves energy. Smart thermostats can automate setbacks for Randolph’s older homes with slow-reacting masonry walls. Avoid drastic setbacks, though—sudden temperature swings can crack plaster and loosen duct liners.

Short cycling

Short cycling is when your HVAC system turns on and off too frequently, never reaching full efficiency. It’s common in Randolph homes with oversized furnaces or leaky ductwork. Each start-up blasts dust from fragile liners into living spaces and accelerates wear on historic masonry ducts.

Masonry duct

Original brick or terra-cotta ductwork found in many Randolph homes built before the 1950s. These channels were designed for gravity heat and often lack insulation or smooth interiors. Over time, mortar erodes and bricks settle, creating gaps that pull in dust and outdoor allergens.

Duct liner

A flexible or rigid insulation layer inside metal ducts that reduces heat loss and noise. In Randolph’s older homes, original liners can become brittle and collapse, sending fibers into the airstream. Modern liner restoration seals leaks and prevents mold growth in historic masonry flues.

Manual D

Manual D is the ACCA standard for designing duct systems to match your HVAC equipment. In Randolph’s older homes, Manual D often reveals undersized or collapsed ducts that waste energy and overwork fragile masonry channels. Correcting these issues improves airflow and protects historic liners.

Frequently Asked Questions