Duct Repair & Sealing in Glen Mills, PA
Duct problems are assumed to belong to old houses, which is why the Glen Mills version catches people out. Most of what we repair around Concord and the neighboring Delaware County townships is builder-installed flexible duct in homes between ten and thirty years old, and it goes wrong in a small, consistent set of ways.
PJ MAC HVAC Service & Repair repairs, seals and rebalances duct systems from our Baltimore Pike office in Glen Mills.
Flexible duct only performs if it is installed straight
Flex is rated on the assumption that it is pulled taut, supported at short intervals and run reasonably directly. Very little of it is. Left slack between joists it sags into a chain of curves, and each one costs pressure. A strap pulled hard across the outside compresses the insulation and the core. A run left twice as long as it needed to be charges the fan for every extra foot. None of it is visible from inside the house, and all of it shows up as the room at the far end never being right.
Attic runs are where the money is
A great deal of duct in this housing lives in a vented attic that passes well over a hundred degrees in July and sits close to outdoor temperature in January. Every leak up there is conditioned air paid for and thrown away, and thin or displaced insulation changes the temperature of the air that does arrive. Sealing and insulating attic runs is normally the highest-value work available here, and it needs no finished ceiling opened.
Boots, takeoffs and the cabinet
Leakage concentrates at connections, not along the middle of a duct. The boot where a run meets the ceiling or floor is frequently not sealed to the drywall, so air escapes into the ceiling cavity before it reaches the register. Takeoffs at the supply plenum, the plenum seams, and the cabinet-to-plenum joint are the other three. Sealing those properly, rather than with tape that lets go, is modest work with a disproportionate effect.
One return for the whole floor
Two-story houses here often have a single central return per floor, sometimes one for the whole house. That works only while the interior doors stand open. Close a bedroom door and the supply keeps pushing air into a room with almost no path back out; the room pressurizes, airflow drops, and the imbalance pushes air through the building shell instead. A return, a transfer grille or a properly sized door undercut fixes bedrooms that no damper adjustment ever would.
How the work runs
- ✓Static pressure and delivered airflow measured before anything is recommended
- ✓Plenum seams, takeoffs, joints and boot-to-drywall connections sealed, not taped over
- ✓Slack, crushed and over-long flexible runs shortened, re-supported or replaced
- ✓Attic and crawl space runs sealed and insulated so they stop conditioning the roof space
- ✓Return capacity or transfer paths added where rooms have supply and no way back
- ✓Zone dampers verified, then the system rebalanced once the leaks are closed
When sealing is not the answer
Occasionally a trunk was undersized on the day it went in, and sealing only makes a badly proportioned system quieter about its problem. We will say that, and quote replacing the section that is wrong. Duct repair is also not duct cleaning: cleaning removes accumulated debris, to NADCA standard using source removal under negative pressure.
Glen Mills Duct Repair & Sealing — Questions We Get
My house is twenty years old. Can the ductwork really be the problem?
Frequently, yes. Builder-installed flexible duct is rated on the assumption it is pulled taut and run directly, and a lot of it was left slack, over-long or crushed under a strap. That geometry costs airflow permanently, it is invisible from inside the house, and it usually presents as one or two rooms that have never been comfortable.
One bedroom is always hot with the door shut and fine with it open.
That is a return-path problem rather than a supply problem. With the door closed the room has air being pushed in and almost no route out, so it pressurizes and the delivered airflow drops away. A transfer grille, a jump duct or a correctly sized door undercut resolves it, and it is much less work than it sounds.
How do you know whether it is the duct or the equipment?
We measure static pressure and airflow before recommending anything. If the blower is working against a high pressure with a clean filter and a healthy motor, the restriction is in the distribution, and no new equipment will change that. It is a fast reading and it decides where the money should go.
One zone will not condition. Is that a duct fault?
As often as not it is the damper rather than the duct. Zone dampers have actuators that stick, fail part-open or lose their calibration, and a control fault presents the same way. That is worth confirming before anybody opens a ceiling looking for a leak.
Is sealing the attic ducts worth it on its own?
In this housing it is usually the single best-value piece of duct work available. Runs in a vented attic sit in extreme temperatures in both seasons, so leaks there are conditioned air thrown straight away, and thin insulation changes the temperature of whatever does arrive. It is also done without touching finished space.
Which areas does the Glen Mills office cover?
Glen Mills and the surrounding Delaware County communities, including Concord, Chadds Ford, Garnet Valley, Thornton, Cheyney, Media, Aston and Chester Heights.
Who serves Glen Mills
Glen Mills calls are handled out of our Glen Mills office at 53 W Baltimore Pike #201, Glen Mills, PA 19342. Call (610) 424-6273 — we answer 24 hours a day.