Ductwork Installation & Repair — Bay Area
Leaky, undersized, or poorly designed ductwork can waste 25–40% of your HVAC system's capacity before the air ever reaches a room. A perfectly good furnace or heat pump will underperform if the distribution system is the weak point. AD Mechanical designs and installs ductwork to ACCA Manual D standards.
Ductwork Services We Provide
- New ductwork design and installation (Manual D sizing)
- Full duct system replacement — attic, crawlspace, or slab
- Duct sealing — Aeroseal or mastic sealing for leaky systems
- Flex duct repair and replacement
- Sheet metal fabrication and installation
- Register and grille replacement
- Duct insulation for attic and crawlspace runs
- Zone damper installation and controls
- Return air improvements for high static pressure
- Duct leakage testing (duct blaster test)
Signs You Have a Ductwork Problem
- Rooms that never reach the setpoint temperature
- Uneven heating or cooling across different parts of the house
- High energy bills despite a new or efficient HVAC system
- Dusty rooms even with a clean filter
- Whistling or rushing air sounds from registers
- Conditioned air you can feel escaping in attic or crawlspace
- Disconnected or collapsed flex duct sections
Duct Leakage Testing
We use a duct blaster pressurization test to quantify leakage before and after sealing work — so you have a real measurement, not an estimate. Most Bay Area homes with original flex ductwork show 20–35% leakage to outside; sealing can typically get this under 5%.
San Jose, Santa Clara, Sunnyvale, Mountain View, Palo Alto, Redwood City, San Mateo, Burlingame, Millbrae, San Bruno, South San Francisco, Daly City, San Francisco, and nearby Bay Area cities