Ventilation

Ventilation

Good ventilation is very important in all areas because:

• Germs need moisture for their growth, so the more moisture removed from food preparation and storage areas the better.
• Excess heat and steam are removed at source, so that a cooler environment is provided for food, thereby minimising bacterial growth. Employees who work in a cooler, less humid environment are more diligent, more productive and suffer less fatigue.
• Excess steam will also result in a need for more frequent decoration and increased operating costs.
• Dry foods such as flour will spoil if good ventilation is not provided.
• Good ventilation in toilets and toilet lobbies prevents foul odours permeating the rest of the building.
• All air intake points should have suitable insect mesh screens to prevent pests getting into the food premises.

Localised Mechanical Extract Ventilation

Localised mechanical extract ventilation must always be provided over heat and steam producing equipment. The canopy serving such areas should be high enough to ensure comfortable head-clearance. Fluted filters must be provided on the canopy in order to prevent grease being drawn into the ducting and on to external walls and roofs at the point of discharge. Of course, there is little point in providing good extract ventilation unless suitable intake ventilation is also provided. Care should be taken in the placing of inlets for ventilation to ensure that they are most likely to take in air of the cleanest quality available in the area.

Grease-laden ducting is a serious fire hazard. Canopies should also have suitable drip-channels, preferably discharging into a small retention cup at one corner to facilitate regular cleaning and a rounded grease channel is easier to clean than a V-shaped one. Wire-mesh grease filters pose an onerous cleaning problem and also pose the risk of pieces of wire mesh falling into food as a result of continuous cleaning with caustic solutions.

Many food premises fail to place ventilation canopies over such items as dish-washers and still-room boilers, or at least site them close to good air extraction points. This should have been considered at the planning stage thus preventing costly intervention at a later date.