Air Makeup Units - Paint Booths

Air Makeup Units ( AMU's ) replace air that is exhausted from a building by paint booths, sanding booths or benches, or any other equipment that exhausts air from inside the building to the outside of the building. They are most often supplied with heating capabilities to provide warm tempered air during the winter and colder parts of the year. During warmer periods they work as blowers pulling air from outside of the building and discharging it into the building. Air makeup units can be connected directly to a paint booth to provide a closed loop system with a bake/cure mode that does not affect the air pressure in your building. Air makeup units can also "dump" air into the building without being connected directly to a paint booth.

You will need and air makeup unit anytime air being exhausted from your building is creating negative air pressure in the building. Negative air pressure in a building can create an unsafe environment for workers and equipment. You will need a heated air makeup unit if you are in an area that get below 60 Degrees F. Most paints need to be applied in temperatures above 60-65 Degrees F.

Your air makeup unit will need to make up for all air being exhausted from your building. The total output capability of the air makeup unit should slightly exceed the total amount of air being exhausted from you building. If you are connecting the air makeup unit directly to a paint booth you should size the air makeup unit with a slightly higher airflow ( measured in C.F.M. - cubic feet per minute ) than the paint booth exhaust. For example, if the paint booth is exhausting 26,000 C.F.M. the air makeup unit should be capable of producing at least 28,000 C.F.M.. This safety factor or design factor makes certain you do not end up with a negative pressure reading in you paint booth.

Yes. The air makeup unit go go inside the building next to or on top of the paint booth. It can go outside of the building on the ground or mounted on the roof of the building. If the air makeup unit is inside of the building it will still need inatke ductwork connecting it to the outside of the building. The intake air for an air makeup unit must come from otside of the building.

The air makeup unit will need electricity and gas. The gas can be propane or natural gas. Gas pressures usually need to be in the 1 P.S.I to 5 P.S.I. range. Most air makeup units require 3 phase power, and voltage.

To get a cure/bake mode with your air makeup unit the unit will need to be connected directly to an intake plenum on your paint booth with ducting. This direct connections allow for providing cure/bake temperatures in your paint booth of 140 Degrees F to 160 Degrees F.

Some products or coatings require humidity controlled environments for applying the coating. Humidity control is accomplished by using an air makeup unit with an air conditioning system to bring the incoming air below the local dew point to condence the moisture out of the incoming air. These systems can use chilled water or DX cooling to bring the incoming air down to below the local dew point. These humidity control systems often take advantage of a booth recirculating system to reduce the amount of air being treated. 80-20 systems that recirculate 80% of the booth air and combine that with 20% of treated air help reduce the cost of air conditioning the air down to below dew point temperature. These systems require constant monitoring of the recirculated air with gas sensors to assure that the air inside of the booth is less than 25% the LFL (Lower Flammable Limit) or LEL (Lower Explosive Limit) of the coatinging being used. Always work with a supplier that has experience with these systems as they are costly and work at the edges of the requirements for the air inside of a booth.

By using an air makeup unit with an air conditioning system. These systems can use chilled water or DX cooling to bring the incoming air temperature down. These air conditioning systems often take advantage of a booth recirculating system to reduce the amount of air being treated. 80-20 systems that recirculate 80% of the booth air and combine that with 20% of treated air help reduce the cost of air conditioning the air down to the desired temperature. These systems require constant monitoring of the recirculated air with gas sensors to assure that the air inside of the booth is less than 25% the LFL (Lower Flammable Limit) or LEL (Lower Explosive Limit) of the coating being used. Always work with a supplier that has experience with these systems as they are costly and work at the edges of the requirements for the air inside of a booth.