Our make up air systems are designed as a "draw-through" heating and ventilation system. The burner combustion zone is located close to the intake/return air plenums, ahead of the blower-fan discharge plenum, allowing various discharge configurations without the use of ductwork. Uniform airflow across the burner insures maximum fuel efficiency as well as constant air-delivery volume. With the combustion taking place before the supply fan, the air-delivery system can compensate for volume expansion as the air is heated.
Other types of make-up air systems push air thorough the burner. These "blow-through" units have certain disadvantages in efficiency. When the fan inlet temperature varies, the fan brake horsepower requirements will change. The blow-through designs will deliver constant air volume, but only if the discharge temperature is constant. If the discharge air temperature varies, the air volume will vary. This can possibly disrupt the balance of exhaust air and make-up air.
American Hood MUA units are complete in every aspect, with all necessary gas and electrical controls included. Attractive standard features as well as numerous options and accessories insure maximum design flexibility and application versatility. With ventilation airflow rates up to 50,000 CFM and firing rates up to 6,000,000 BTU/HR, various model choices have become popular over the years.
For more information click on the product links or call us at 1-800-854-3267.