Note that not both exhaust fans are required for hood exhaust.
Kitchen hood exhaust temperature. The hvac designer should compare the submitted exhaust val ues with the minimum listed ul 710 exhaust rates for capture containment table 1. Kitchen exhaust continued ansi ashrae ies standard 90 1 2010 4 air conditions and when dvs s or energy recovery devices are required. Always consider the exhaust flow recom mended by the hood supplier. Factory built commercial cooking recirculating systems 3.
Example a shows a kitchen that does not have more than 5 000 cfm of hood exhaust. Then work with the equipment supplier to achieve a workable hood size and equipment layout. Most hood manufacturers also offer hood. Hoods shall be type 1 or type 2 and shall be designed to capture and confine cooking vapors and residues.
To work it out find out the gas supply to the cookers convert it to energy and calculate the temperature rise using the kitchen exhaust rate. 3 backshelf hoods are available as exhaust only hoods i e. These have no provision for introducing tempered or un tempered air integral to the hood. Commercial kitchen restaurant duty exhaust hood wall canopy stainless steel exhaust hood with baffle hood filters high temperature light fixtures and 10 round exhaust riser 4 long hood.
Calculation of air volume to exhaust correction factors according to the type of installation chart 2 type of installation multiplication factor wall mounted hood 1 0 single island hood 1 2 double island hood 1 15 partial stainless steel end skirt on each side of the hood see section k 0 95 full stainless steel end skirt on each side. Factory built commercial exhaust hoods which are tested 2. In commercial kitchens exhaust hoods are often used in combination with fire suppression devices so that fumes from a grease. Quick calc on a typical exhaust hood indicates about a 10 oc temperature rise.
A kitchen hood exhaust hood or range hood is a device containing a mechanical fan that hangs above the stove or cooktop in the kitchen it removes airborne grease combustion products fumes smoke heat and steam from the air by evacuation of the air and filtration. The illustration above shows a typical commercial kitchen application utilizing a roof mount upblast exhaust fan or wall mount upblast exhaust fan in conjunction with a supply fan. This would be a worst case steady state scenario but might be exceeded if there is a flare up when cooking. 4 the length of a backshelf should be a minimum of the length of the cooking equipment.
Thermophoresis causes particles to migrate from hot to cold air temperatures due to uneven thermally induced collisions with gas molecules. When the exhaust air temperature is elevated and there is an appreciable wall exhaust air temperature difference the phenomena of thermophoresis becomes an important deposi tion mechanism.