A thorough visual inspection is the best way to verify the cleanliness of your heating and cooling systems. All portions of the system should be visibly clean - i.e., such that you cannot see any debris with the naked eye. Have the contractor show you the following areas in your system after the cleaning work to verify that the job was performed satisfactorily:

General

Did the contractor clean the entire heating and cooling system, including ductwork and all components.

Heating

Is the heat exchanger surface visibly clean?

Cooling

Are both sides of the cooling coil visibly clean?

Components

If you point a flashlight into the cooling coil, does light shine through the other side? It should if the coil is clean.

Are the coil fins straight and evenly spaced (as opposed to being bent over and smashed together)?

Is the coil drain pan completely clean and draining properly?

Access Doors and Covers

Are newly installed access doors attached with more than just duct tape (i.e., screws, rivets, mastic, etc.)?

With the system running, there should be no air leakage through access doors or covers. Is this the case?

Plenums

Is the return air plenum free of visible dust or debris?

Do filters fit properly and are they the desired efficiency?

Is the supply air plenum (directly downstream of the air handling unit) free of moisture stains and contaminants?

Blower

Are the fan blades clean and free of oil and debris?

Is the fan compartment free of visible dust or debris?

Metal Ducts

Are interior ductwork surfaces free of visible debris? (Select several sites at random in both the return and supply sides of the system)

Fiberglass Duct Surfaces

Is the fiberglass material in good condition (i.e., free of tears and abrasions; well adhered to underlying materials)?

Air Vents

Have you air vents been firmly reattached to the walls, floors, and / or ceilings?

Are the air vents visibly clean?

System Operation

Does the system function properly after cleaning?

Is the system operating free of any new or unusual noises?