LEV-CO’s Non-Tempered Air Make-Up Systems replaces exhausted air more efficiently and with more comfort than conventional Air Make-Up air systems. Ideal for production facilities that generate heat, for example welding shops where welding processes generate up to 450,000 BTU per hour per welder.
Non-Tempered units are grouped into 2 different types:

• 100% Outdoor Air: These units draw outside air and consist of a simple Axial fan, motorized inlet damper, Insulated cabinet and flow straightener.
• Modulating units – 0-100% Outdoor air: these units draw a variable amount of outside air from outside and when the internal temperature drops below the customer’s set point (EG: 70 degrees F) the THERMOSTAT controlled modulating air-mixing system allows air to be drawn from OUTSIDE or INSIDE in order to maintain desired indoor temperature. This solution is most often selected when the production level cannot be guaranteed or additional heat sources are not available.

Both solutions are aided by custom engineered flame retardant fabric distribution ducting, where we able to take advantage of the STRATIFIED heat in ceiling, creating the equivalent of lowering a conventional thermostat by ½ degree F per foot of ceiling height or provide MAKE-UP without additional heat.
This is accomplished by discharging the air in HIGH velocity air jets as close to the ceiling as possible. The result of the mixing is that the fresh air is heated to room temperature very quickly before it reaches the lower occupied area. This is extremely effective in welding shops where each welder can generate as much as 450,000 BTU per hour in heat.
This “De-Stratifying” air distribution method has the added benefit of diluting and cooling any “Fugitive emissions/smoke” in the ceiling space and allows this air to be drawn down to floor level where it can be filtered and or exhausted by local exhaust ventilation systems.
When no fresh air is needed, the system can be shut down and the outside air dampers will close automatically or the system can be run on one hundred percent (100%) re-circulated air.
Conversely, if cooling air is required, “Bi-Flex” ducting can be selected (Optional). Bi-Flex ducting allows the air to continue to be exhausted into the ceiling space in the winter months AND then be re-directed downwards to the workers in summer months. This method leaves the bulk of the hot air in the ceiling space and places high velocity cooling air towards the worker. (The velocity shall not be high enough to disturb welding gases/processes).