What is Ductwork?
Plain-English explanation from a licensed Utah HVAC, plumbing, and electrical contractor.
Ductwork is the metal or flexible tubing system that carries conditioned air from your furnace or air handler to each room and returns it for re-conditioning.
Full Definition
Residential ductwork comprises a supply system (which delivers conditioned air to rooms via registers) and a return system (which pulls air back to the blower). Properly designed ductwork follows ACCA Manual D for sizing: trunk and branch dimensions, register selection, and return path are calculated to deliver each room's Manual-J load at design static pressure. Most Utah homes use rigid sheet-metal trunks with insulated flex-duct branches.
Studies by the U.S. Department of Energy show typical residential duct systems leak 20–30% of conditioned air into attics, crawlspaces, and wall cavities. Sealing ducts can recover that loss and is one of the highest-ROI HVAC investments in Utah's climate.
Common Questions
Should I replace or seal my ductwork?
If the existing ducts are properly sized but leaky, sealing (with mastic or Aeroseal) is much cheaper. If the ducts are undersized or have major design flaws, redesign and replacement of problem sections delivers better results long-term.
How do I know if my ducts are leaking?
A blower-door + duct-blaster test gives an exact measurement. Anecdotal signs: dusty registers, rooms that won't condition, big bills, and visible disconnections in attic or crawlspace runs.
Related Terms
Duct Sealing
Duct sealing closes the gaps, holes, and leaky joints in your duct system so the conditioned air your HVAC produces actually reaches the rooms instead of escaping into the attic or crawlspace.
Static Pressure
Static pressure is the resistance your blower has to push against to move air through the duct system — too high and the blower struggles, efficiency drops, and the system runs hot.
Manual J Load Calculation
Manual J is the industry-standard whole-house heat-loss and heat-gain calculation that determines exactly how big your furnace and AC need to be — too big or too small both hurt comfort and efficiency.
Recent HVAC work in Utah
A few installs and service calls from the AYSP crew.
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