Ventilation Requirements

Depending on local codes, ventilation requirements may vary. A basic formula is as follows: 100 to 150 CFM (cubic feet per minute) per square foot of floor space that the appliance or line up occupies. For example, one standard six burner unit, which measures 36" wide by 38" deep, equals approximately 9 square feet of floor space, therefore 900 to 1,350 CFM of exhaust is required.

Units with charbroilers may require more CFM exhaust; check with local authorities.

The hood should extend a minimum of 6" over all exposed sides of an appliance or line up. Seldom can the units be without rear clearance, so figure 4" in the rear.

For every cubic foot of gas that is burned, 11 cubic feet of by-products are produced. These by-products must be vented to the outside.

Ventilation systems need to be properly balanced to ensure that all the by-products are exhausted. There must be an adequate supply of fresh air for proper combustion and still a very slight negative pressure in the kitchen.

Sometimes a hood system will be operating perfectly as per its manufacturer’s specifications, however there is still a problem with the gas-cooking appliance. The hood system may not be compatible with the gas appliance under it. In these instances, the service contractor for the hood system and the appliance Servicer will have to work together to attempt to correct the problem. If it is determined that the hood system is not compatible with the appliances under it, it is imperative that this information be communicated to the end user, the dealer and all parties involved, especially the Vulcan-Hart Company.

If the fresh air system (make up air) is such that ovens and griddles are experiencing fluing problems, there will be component failures due to excessive heat. If the open burners are fluttering or blowing around due to make up air being directed at the top or front of the unit delayed, no ignition will occur, and the appliance’s performance will be severely affected. If it is determined that any of these conditions exist, the appliance warranty will be voided.

Some cities allow the use of a direct vent system in lieu of a motor-driven exhaust system to vent a bake oven. Check with local authorities.

To increase appliance performance and minimize energy consumption of the ventilation system:

•Add side panels on canopy hoods.

•Avoid make up air diffusers close to hood or re direct air away from top and/or rear of appliance.

•Add multi-or variable-speed exhaust and make up air fan controls.

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