Semi Downdraft Paint Booths
Semi-downdraft paint booths operate much like a crossdraft since the exhaust is still achieved via the rear of the paint booth workspace, however the incoming air is now introduced to the workspace through small section in the ceiling located at the front of the paint booth.
This creates a draft pattern that is directed at a diagonal from the filtered area of the ceiling to the exhaust point at the rear of the paint booth.
Advantages of Semi Downdraft
- The airflow pattern gives a slight advantage over crossdraft paint booths since the incoming air is not going across the painted object but rather on a diagonal heading somewhat downward.
- A semi downdraft paint booth is also a very economic choice since concrete is not necessary and the cost of the unit is generally a mid-range price from most paint booth manufacturers.
Disadvantages of Semi Downdraft
- A semi downdraft paint booth still suffers from the fact that the painter is most likely going to be in the way of the draft and will be exposed to more overspray than need be.
- Additionally, the downward or diagonal shape of the draft, can create a dead zone at the front of the paint booth that gets little or no airflow.
- The painter must think ahead and position the area to be sprayed toward the back to get the best air flow. If a part or area of an object must be painted at the front of the paint booth, the area may not exhaust properly or even worse, the overspray may begin to swirl in the dead zone, picking up dust or dirt from the floor and laying it into the finish.