How do replacement air ceiling registers affect the hood?
The placement and location of ceiling registers (diffusers) for the introduction of replacement air can have a direct impact on the proper operation of the exhaust hood. Diffusers that have been designed for commercial spaces, such as “four way diffusers” were developed to have a high induction capability. That means they discharge at a relatively […]
Is cooking equipment makes and models important for preliminary engineering?
Commercial cooking equipment makes and models are important for preliminary engineering Outdated methods of ventilation design categorized commercial cooking equipment (appliances) into different classes; light, medium, heavy-duty and extra heavy duty (solid fuel). The average exhaust rates were established for each category based on rules of thumb, cfm per foot of hood. With the advent […]
What temperature should the supply air be introduced to the Kitchen?
Engineers will typically design for a supply air temperature at 10 degrees above traditional occupied spaces outside of the kitchen. Supply air is usually brought into an occupied space at 57°F/14°C off the coil to mix with room air to maintain a specified space temperature at design conditions. In a kitchen, due to the air […]
Who is the “AHJ” and what authority do they have on a project?
AHJ refers to “The Authority Having Jurisdiction”. The AHJ has final authority for the interpretation of fire and building codes (NFPA, IMC). Although model codes are interepted fairly consistently, a number of municipalities may have variations or interpret certain elements of the codes differently. In some cases there are additions not covered in the model […]