Custom Ductwork ModificationsBuilt in Our Portland Shop
Rerouting, resizing, adding zones — we design and fabricate it all in-house. Fix the hot and cold spots your original ductwork never could.
In-House Sheet Metal — From Design to Install
We don't order parts and wait — we cut, bend, and fabricate custom ductwork in our own shop for faster turnaround.
When Your Ductwork Needs Modification
Badly sized or poorly designed ductwork is the #1 reason Portland homeowners can't get comfortable. Older Portland bungalows, ranches, and split-levels are notorious for undersized ducts, too few return air paths, and registers in the wrong spots. When you add a room, finish a basement, or upgrade HVAC equipment, existing ductwork usually can't keep up. We use Manual D calculations to design modifications that actually deliver balanced airflow to every room.
Ductwork Modifications We Handle
From a single damper install to a full system redesign — we have the tools, the shop, and the experience to get it done.
System Rebalancing
Adjust dampers, resize ducts, and modify registers to deliver even airflow to every room. Fix hot/cold spots without replacing your entire system.
Zone Additions
Add ductwork to new rooms, finished basements, attic conversions, or home additions. We integrate new zones seamlessly with your existing system.
Custom Fabrication
Custom plenums, transitions, and duct sections — cut, bent, and assembled in our own shop. Built to fit your home, not forced to fit from a catalog.
Trunk Line Upgrades
Undersized trunk lines starve distant rooms of airflow. Upsizing the mains lets your system push enough air to every branch.
Register Relocation
Move registers to better locations, add returns for improved circulation, or switch from floor to ceiling registers for better comfort.
Damper Installation
Install manual or automatic dampers to control airflow to different zones. Balance your system without expensive zoning equipment.
6 Signs Your Ductwork Needs Reworking
Rooms That Won't Heat or Cool
If certain rooms are always too hot in summer or too cold in winter — regardless of thermostat settings — undersized ducts or poor layout is almost always the culprit.
Weak Airflow from Vents
When you hold your hand to a register and barely feel air moving, the ductwork may be undersized, have too many bends, or be restricted by crushed flex duct.
High Energy Bills
Bad ductwork forces your HVAC to run longer cycles. If your PGE or NW Natural bills seem high for your home's size, inefficient ducts may be driving the cost.
Noisy Duct System
Whistling, popping, or banging noises from your ducts indicate airflow problems. Undersized ducts create high-velocity air that whistles; improper supports cause banging.
Recent Home Renovations
If you've added rooms, finished your basement, converted your attic, or removed walls, your existing ductwork probably needs modifications to serve the new layout.
New HVAC Equipment
Upgrading to a larger furnace or AC requires matching ductwork. Many Portland homes have ducts sized for older, smaller equipment that can't handle modern high-efficiency systems.
Dealing With Any of These?
We'll assess your duct system, pinpoint the problem, and tell you exactly what it'll take to fix it.
Call (503) 698-5588 for Free AssessmentHow a Ductwork Modification Job Works
Proper engineering, custom fabrication, and verified results — not guesswork.
Full System Assessment
We inspect every duct run, measure airflow at each register, and identify restrictions, leaks, and design problems. We also check your equipment capacity against what the ductwork can actually deliver.
Manual D Design
Manual D is the industry standard for duct design. We calculate the exact CFM each room needs and engineer modifications to deliver it. No eyeballing — just math.
Custom Fabrication
Our sheet metal shop builds custom ductwork, plenums, and transitions to spec. Everything fits because we made it for your specific layout — no generic parts.
Professional Installation
Our NATE-certified technicians install all modifications with proper supports, sealed connections, and insulation where needed. We protect your home during work and clean up completely.
Airflow Verification
After installation, we measure airflow at every register to verify balanced delivery throughout your home. We adjust dampers and make final tweaks to optimize performance.
Serving Portland Metro Area
Custom ductwork modifications across the greater Portland area
Portland Ductwork Modification FAQs
Related HVAC Services
Duct Cleaning
Remove dust, allergens, and debris for cleaner air and improved efficiency.
Duct Sealing
Seal air leaks to maximize efficiency and comfort throughout your home.
Duct Insulation
Prevent energy loss and condensation with proper duct insulation.
Furnace Installation
Pair your modified ductwork with a new high-efficiency furnace.
Ready for Better Comfort in Every Room?
Get a free ductwork assessment and discover how modifications can transform your home's comfort.
Free assessments • In-house fabrication • Since 2008