Duct Testing & Sealing in Jackson, MS

Because without it, every statement anyone makes about your ductwork is a guess — including ours. A duct leakage test converts the condition of a hidden system into one number: the air escaping the ducts, measured in CFM and expressed as a percentage of the airflow your system moves. That number tells you whether sealing is worth doing, where the work in the job actually is, and afterward whether it accomplished anything.

It also settles arguments the rest of the trade keeps having by feel. Rooms that will not cool get blamed on undersized equipment, humidity on the thermostat, dust on the filter. A leakage test plus a total external static pressure reading separates a leak from a restriction from a capacity problem in one visit.

The common ones are: rooms at the end of long runs that never keep up in summer; equipment that runs continuously without satisfying the thermostat; a house that stays humid and clammy at a comfortable temperature; an attic smell when the system first starts; and fine dust reappearing at the supply registers within days of cleaning.

Every one of those also describes a failing or undersized air conditioner, which is why so many Jackson homeowners replace equipment and stay disappointed. The tell that points at ducts specifically is the return-side evidence — the attic smell, the fiber-looking dust at the registers, the humidity that will not come down. Those mean unconditioned air is being pulled into the system, not merely lost from it. That is an indoor air quality problem as much as a comfort one, and a test confirms it in a single visit.

With a calibrated fan and a pressure gauge. We temporarily seal the supply registers and return grilles, connect the fan to the duct system, and pressurize the ducts to a reference pressure of 25 Pascals. To hold that pressure, the fan has to replace exactly the air that is escaping — so the airflow through the fan, read in CFM, is the leakage rate. Nothing is inferred.

The percentage is the part that matters. Leakage in CFM only means something next to the airflow your system actually moves, so we measure that too and divide — which is what makes the result comparable from house to house and from before sealing to after it. We can also isolate leakage to the outside — the portion escaping into the attic or crawl space rather than into the house — because that is the share doing the real damage.

On some houses clearly yes, on some houses clearly no, and the test is what tells them apart — which is the reason we test before we quote. We will not attach a savings figure or a payback estimate to it, because those numbers get invented in this industry far more often than they get measured.

What we will describe is the mechanism. Air lost from the supply side is conditioned air you paid for going into a 130°F attic instead of a bedroom; air pulled in through the return side is attic dust, insulation fiber, and humid unconditioned air entering the airstream your family breathes. Sealing stops both, and the re-test shows by how much. If your baseline test comes back tight, we will say so and you should spend your money elsewhere — that outcome happens, and it is why the test comes first.

Cleaning treats what is in the duct. Sealing treats what the duct does. They are separate services solving separate problems, and they are constantly sold as though they were the same one.

The practical consequence is worth understanding before you book either: a duct that got dirty because it leaks will get dirty again. Return-side leakage is a vacuum on the attic, so cleaning a leaking system removes the debris that is there today and leaves the mechanism that delivered it fully intact. Sealing addresses the mechanism. On plenty of Jackson homes the right sequence is to test first, seal what the test found, and then decide whether the ducts still warrant air duct cleaning at all — a question that page answers from the cleaning side, against the EPA's own as-needed criteria.

There are aerosol-based products marketed for interior sealing, and we do not lead with them. The EPA specifically cautions that the effectiveness and long-term safety of sealants applied inside duct systems has not been fully established, and we are not going to put a material inside the airstream your family breathes on the strength of a marketing claim.

Our default is mechanical and external: mastic and fabric-backed tape at the joints, mechanically fastened connections, and proper sealing at the boots, plenum takeoffs, and return panel seams the leakage test points to. It is slower attic and crawl-space work, but it is durable and you can see it. Where a run is beyond sealing — crushed, disconnected, or deteriorated — the honest recommendation is to replace that section rather than paint over it.

Sealing fixes a duct system that leaks. It cannot fix a duct system that was designed wrong, and telling those apart is a design question with a published answer: Manual D duct design, the industry standard for residential ductwork. Manual D sizes each trunk, branch, and return for the airflow that room needs at a static pressure the equipment can actually deliver against — it is the document that says what your ductwork should have been.

So we compare what you have against what Manual D would call for. A system with adequate duct sizing, a properly sized return, and reasonable static pressure that simply leaks is a sealing job. A system where the return is a single undersized hallway grille, where the branches were never sized for the rooms, or where total external static pressure sits far above what the equipment is rated to work against is a design problem — sealing it only tightens a layout that was never going to deliver the airflow anyway. Nobody in this market names Manual D, which is a strange thing to leave out of a conversation about spending money on ductwork.

The baseline test itself is typically under an hour on a normal single-system home: setting up the calibrated fan, temporarily sealing the registers and grilles, pressurizing to 25 Pascals, and recording the leakage. The static-pressure, airflow, and temperature-split readings add a little more, and then we walk you through the results before you decide anything.

Sealing is the longer half — an attic and crawl-space job measured in hours, depending on how much of the system is reachable and how many joints and boots need work. We schedule all of it inside our posted hours: Monday through Friday 7am to 6pm, Saturday 9am to 5pm, closed Sunday. If a job needs more time than one visit allows, we tell you that up front instead of rushing the sealing to fit the day.