Lone Star Cooling and Heating
Get help with Ductwork & Duct Sealing
Call Lone Star Cooling and Heating, have us call you, or describe the issue.
Prefer to talk?
Call (325) 219-0005Finding where a duct system loses air, in the attic, the crawlspace or at the equipment, and sealing the joints and gaps so more of what the system heats and cools reaches the rooms it was meant for.
01Ductwork
Duct problems rarely announce themselves directly. These are the signs that usually lead back to them.
Weak airflow at a few vents often traces back to a leaking joint or a run that has come apart somewhere between the equipment and the room. Sealing and reconnecting the ducts sends that air back to where it was headed.
A leaking return duct draws in air from wherever it runs, and in an attic, crawlspace or garage that air carries dust, insulation fibers and odors. Sealing the return side stops the system from pulling that air into the rooms.
When ducts leak into a space outside the heated and cooled part of the building, the equipment has to run longer to make up for air that never arrives. A leakage test shows how much is escaping, and sealing recovers it.
Ducts can separate at a joint or slip off a fitting, and the air meant for a room then pours into the attic or crawlspace instead. Reconnecting the run and sealing the joint restores the room’s supply.
In humid weather, cold supply ducts with torn or missing insulation collect condensation, and it can drip onto the ceiling below. Restoring the insulation and its outer jacket, and sealing any leaks at those joints, stops the dripping.
02Urgency
Most duct trouble costs comfort and energy slowly. A few situations should not be left.
None of this fixes the ducts. It keeps people safe and limits the damage until they are seen.
If a carbon monoxide alarm sounds, get everyone out into fresh air and call 911. Leave the heating off until it has been checked.
Switch the system off at the thermostat so the ducts stop sweating, and keep people clear of any light fixture or outlet in a wet ceiling. A bucket under the drip limits the damage.
Ductwork & Duct Sealing
Serving Abilene, TX.
03Where ducts leak
The leaks that matter most are the ones outside the space the system is heating or cooling.
Ducts leak most at their joints: where runs meet the equipment, where branches split from the main trunk, and where each run ends at a boot behind a vent. Flexible duct can also tear or pull free of its collar. Supply leaks push heated or cooled air into the attic or crawlspace, while return leaks draw that space’s air back into the system.
In hot climates, attic ducts spend the summer in one of the hottest places on the property. Cooled air escaping there is simply lost, and a leaking return pulls attic heat and dust straight into the equipment. The insulation wrapped around attic ducts matters for the same reason, since a thinly insulated run warms the air inside it before that air reaches a room.
04Sealing methods
The two approaches reach different leaks, and many jobs use both.
A technician brushes mastic over each seam that can be reached, backs larger gaps with mesh, and reconnects runs that have come apart. It handles the biggest leaks and any loose connections, but only on ducts someone can physically get to.
With the vents covered and the equipment protected, the duct system is pressurized and an aerosol sealant is blown through it. The particles collect at the edges of each leak until it closes, including leaks hidden in walls and ceilings. It cannot bridge large gaps or reconnect a fallen duct, so those are fixed first.
05What changes the job
Ducts in an open attic or a tall crawlspace can be sealed joint by joint. Runs under a low roof, in a tight crawlspace or inside finished walls and ceilings may only be reachable from inside the ducts.
Sheet metal, duct board and flexible duct each leak in their own ways and are sealed differently. Old flexible duct that has turned brittle, or duct board that is crumbling, may be past sealing and better replaced.
In an attic or crawlspace, sealing a duct and leaving its insulation torn or missing solves only half the problem. Damaged insulation is usually repaired while the joints are being sealed.
06Questions
It depends on where the ducts run and how leaky they are. Ducts inside the heated and cooled part of the building leak into rooms that want the air anyway. Ducts in an attic, crawlspace or garage lose it to a space nobody is trying to heat or cool, and that is where sealing makes the biggest difference.
Not for long. Cloth-backed duct tape dries out and lets go, especially in the heat of an attic. Duct joints are normally sealed with mastic, a thick paste brushed over the seam, or with foil tape rated for ductwork.
The usual method is a duct leakage test. The vents and returns are covered, a calibrated fan pressurizes the duct system, and the airflow needed to hold that pressure shows how much is escaping. Smoke or a thermal camera can then help locate the individual leaks.
A smell of gas, a carbon monoxide alarm, a burning electrical smell, or no heat or cooling in dangerous weather: urgent. A system that runs longer than it used to, a new noise or one room that is off: worth a visit soon, but not tonight.
What the system is doing, when it started, what the thermostat is set to and what it reads, and whether the outdoor unit is running. The age of the equipment and a photo of its label help a technician arrive prepared.
Lone Star Cooling and Heating
Call Lone Star Cooling and Heating, have us call you, or describe the issue.
Prefer to talk?
Call (325) 219-0005