Ductwork that is designed, sealed and tested
Undersized, crushed or disconnected ducts can undo the performance of the best equipment. New ductwork starts with a design and ends with measurements.
Why ducts matter as much as equipment
Your furnace, air conditioner or heat pump creates comfort, but the ducts deliver it. When ducts are too small, poorly routed, leaking or collapsed, airflow drops, rooms go uncomfortable, noise increases and equipment strains. Many homes have ductwork that was installed quickly decades ago and has since been crushed, disconnected or outgrown by new equipment and additions.
Replacing ductwork is an opportunity to correct those problems permanently. A proper design calculates how much air each room needs, sizes trunks and branches to deliver it at reasonable static pressure, and makes sure return air is adequate. Installation then follows that design with sealed joints, supported runs and insulation where ducts pass through unconditioned spaces.
We handle full duct system replacements, partial replacements of damaged sections, new runs for additions and finished basements, and return air corrections.
Duct project details
- Design standard
- ACCA Manual D sizing
- Materials
- Sheet metal trunks, rigid and flex branches
- Verification
- Static pressure and register airflow
Indications that ducts need replacing
Duct problems often hide behind symptoms people blame on the equipment.
Rooms far from the system stay uncomfortable
Long runs with inadequate sizing or too many turns deliver little air to distant rooms, leaving them hot in summer and cold in winter.
Whistling or roaring at registers
High air velocity through undersized ducts or restrictive grilles creates noise and signals high static pressure.
Visible damage in the attic or crawlspace
Crushed flex duct, torn insulation, disconnected joints and sagging runs waste conditioned air where no one benefits from it.
Dust and odors after the system runs
Leaky return ducts pull air from attics, garages and crawlspaces, bringing dust and fumes into living spaces.
A new system that underperforms
New equipment connected to old, undersized ducts often cannot reach its rated capacity or efficiency.
Additions or remodels
Rooms added onto the original home frequently get a single branch tapped from the nearest duct, which rarely delivers enough air.
How a duct replacement project runs
Measure and inspect
We measure room loads, inspect existing ducts and record static pressure and airflow to identify restrictions, leaks and design flaws.
Design the system
Using Manual D, we size trunks, branches, returns and registers so each room gets its required airflow at an acceptable static pressure.
Proposal and scheduling
You receive the design summary, materials, scope and a flat price, along with an estimate of how long the work will take.
Removal and installation
Old ducts are removed, and new ducts are installed, sealed at every joint with mastic or listed tape, supported and insulated as required.
Test and balance
Static pressure and airflow at registers are measured, dampers are adjusted, and results are shared so you can see the improvement.
Static pressure, returns and the details of a good duct install
Static pressure is the resistance air meets as it moves through the duct system. Most residential blowers are designed to operate within a specific external static pressure range, commonly around half an inch of water column total, though manufacturers specify the exact figure. When ductwork is undersized or restrictive, static pressure climbs above that range, airflow drops and the blower works harder. Measuring static pressure before and after a duct project gives an objective view of whether the new system performs as designed.
Return air is the most frequently neglected part of residential ductwork. A home with a single small return, or with bedroom doors that close off supply air without a path back, cannot circulate air properly. Adding returns or transfer grilles often solves comfort problems that no amount of supply ductwork could fix. On the supply side, flex duct performs well when it is pulled tight, kept as short as practical and supported without sagging. Sheet metal is preferred for trunks and long runs because it holds its shape and resists airflow better.
Sealing is part of the install
Every joint, seam and connection on new ductwork is sealed with duct mastic or UL 181 listed tape. Standard cloth duct tape is not used, because its adhesive fails over time and joints slowly open back up.
How duct design affects comfort and noise
Ductwork is the delivery system for heating and cooling, and its design determines whether each room receives the air it needs. A good duct design starts with the airflow required for each room based on its heating and cooling load. Supply ducts are then sized to carry that airflow at reasonable velocity, while return ducts bring air back to the equipment.
Undersized ducts force air through at high velocity, creating noise and raising static pressure, which reduces equipment efficiency and can shorten blower motor life. Oversized ducts can reduce air velocity too much, leaving rooms stuffy. Long, poorly supported flexible duct runs with sharp bends restrict airflow even when the diameter looks correct.
Returns are often the weakest part of older systems. A single central return may not allow air to flow back from closed bedrooms, creating pressure differences that reduce comfort and draw unconditioned air from attics or crawlspaces. Adding returns or transfer grilles can solve these problems.
Duct replacement projects begin with measuring static pressure and airflow, then designing changes based on those readings. New ducts are sealed at joints and connections, insulated in unconditioned spaces and supported properly. After installation, airflow and static pressure are measured again to confirm improvement.
Ductwork mistakes that hurt performance
These installation errors are common and costly.
Using flexible duct carelessly
Kinked, sagging or overly long flexible ducts restrict airflow. Proper support and short runs are essential.
Ignoring return air
Insufficient return air raises static pressure and reduces comfort. Returns should be sized as carefully as supplies.
Leaving joints unsealed
Unsealed ducts leak conditioned air into attics and crawlspaces and can pull in dust and moisture.
Skipping insulation in unconditioned spaces
Uninsulated ducts lose heat in winter and gain heat in summer, reducing efficiency.
Not measuring before and after
Without static pressure and airflow measurements, it is impossible to know whether duct changes solved the problem.
What affects a ductwork project price
- Extent of replacement
- Replacing a few damaged runs costs far less than a complete system replacement with new trunks, branches and returns.
- Access
- Open attics and basements allow faster work. Crawlspaces, tight attics and finished spaces take longer and may require patching.
- Materials
- Sheet metal costs more than flex duct but lasts longer and moves air more efficiently, especially for trunks and long runs.
- Insulation requirements
- Ducts in unconditioned spaces need insulation to the level local code requires, which adds material and labor.
Ductwork questions
Well-installed sheet metal ductwork can last for decades. Flex duct generally has a shorter life, especially in hot attics where the outer jacket and insulation can deteriorate.
Adding registers without addressing duct sizing and return air often does not help, and can reduce airflow elsewhere. A design review finds the real limitation.
If ducts are being replaced, cleaning the old ones is unnecessary. Cleaning can help existing ducts that are sound but dirty, especially after construction.
In many cases, yes. Properly sized ducts lower air velocity and static pressure, which reduces whistling and blower noise.
Partial replacements can be done in a day. Full system replacements typically take a few days depending on the home's size and access.
Get air to the rooms that have been missing it
Schedule a duct evaluation and receive a design summary with a flat project price.