Return air in, supply air out. The difference across the evaporator coil is the fastest honest read on whether a system is healthy, and it takes four minutes. We measure it before we quote anything.
400CFM
Airflow per ton of cooling. The first number checked on a sizing complaint.
0.5IN WC
Total external static pressure most residential duct systems are designed around.
8-13MERV
Filter range a typical residential blower can pull through without starving.
±3°F
Room to room variance a properly balanced system should hold.
Four services
01
Warm air at the vents is usually low charge, a fouled evaporator coil, or a failed run capacitor. We read the split and the static pressure before anyone touches refrigerant, because two of those three are not a refrigerant problem.
02
No heat. We test the igniter, the flame sensor, and the high limit in that order, then tell you which one failed.
03
Sizing comes from a load calculation, not from the tonnage of the box being replaced.
04
A leaking return pulls attic air into the house, which is why the filter loads up fast and the far bedroom never catches up. We seal the plenum and the branch joints, then re-balance so the runs at the end of the trunk get their share.
Plates 01 to 04
Example imagery, not photographs of completed jobs. A live site would carry the owner’s own pictures of their own work here.
Four steps
01
Tell us what the system is doing. We book an arrival window rather than a whole day.
02
Temperature split, static pressure, and charge. The readings decide the diagnosis, not the age of the unit.
03
What failed, what it costs, and what happens if it waits. You approve before anything is replaced.
04
Floors covered, work done, and the same readings taken again so you can see what changed.
Figure 01
Air takes the cheapest path available to it. A joint that has opened up is a cheaper path than the bedroom at the end of the trunk, so that bedroom loses every time. These are drawings, not photographs.
Open joint upstream. The runs past it never see full airflow.
Joint sealed. Every run on the trunk gets its share.
03 entries
Often not. A unit that short cycles or blows warm can be a capacitor, a contactor, or a clogged coil. We measure first and replace what actually failed.
A straight swap of a furnace and coil is usually one day. Reworking ductwork adds a day or more, and you will know which one you are looking at before the work starts.
Usually airflow rather than equipment. Undersized returns, crushed flex duct, and dampers left where the last person put them all show up as one room that never catches up.
Book a diagnostic
Warm air, no heat, a loud start, one room that never catches up. The more specific you are, the shorter the visit is.