HVAC / AIR QUALITY
HVAC IN THE KITCHEN
Julian Shine, Managing Director at Shine Catering Services, explores why FMs should insist on a catering- specific balanced ventilation system in kitchen environments.
It is a viewpoint generated from bitter experience, but I can’t stress enough the importance of a catering- specific ventilation system in professional kitchens. You would think it nonsensical that the manufacturer of a passive ventilation hood, designed to service the volume flow rates and capture containment overhangs required by the cooking equipment for compliance with DW 172-2018 V2, could be leant on to solve a building’s ventilation issues. So did I.
Integration of the building’s ventilation with the catering specific ventilation will often be undertaken as an arithmetical exercise, with the consulting engineer not perceiving the real-world effect it will have on the performance of the extremely sensitive balance within the cooking area.
If your ventilation consultant has used the kitchen canopies to provide the majority of general room air change rates for the whole building with supply air distributed around the building, check that they haven’t created a wind-tunnel within the architectural design. A high velocity of air across any cook line will destroy the containment capabilities of a correctly ventilated and sized canopy.
In addition, a kitchen must remain under negative pressure to prevent the escape of odours to the surrounding building, with more sensitive environments targeting larger differentials between the extract and supply rates. Natural infiltration into the kitchen will then provide the balance of between 25% and 5% of your extract rate.
If your cookline has a large volume flow rate associated, be mindful of where this balancing air will come from and
36 | TOMORROW’S FM
its effect on doors. If a relatively open kitchen, there are usually few issues, but if a closed facility in a new airtight building, doorways can be rendered difficult to pull open from the outside of the kitchen or permanently sucked open. We have seen facilities that would fail to contain the plume when doors close to the cook line are opened, as the cross draughts blow away the smoke, water, grease and toxins.
Another issue we see is the provision of supply air in the wrong place in a dedicated catering ventilation system. Building constraints may dictate the points at which supply air can be delivered, however, cold air being sucked across a hot pass results in cold, skinned plates of food being served. If the hot pass is directly in front of the cookline and the supply air is integrated into the front face of the canopy, inboard air and cooling spots will lessen the air pushed towards the pass.
The purpose of the catering ventilation system is to provide a safe and comfortable working environment for the operators, protect the building fabric by containment of the cookline plume, and to provide a serviceable transit through the building’s fire compartments to an appropriate intake and discharge point. This is best provided by an independent catering design without integrating the ventilation of other areas within a building.
Even when the kitchen has been designed well and the volume flow rates have been calculated correctly, it is always essential that the effect of the velocities of air within different areas of the kitchen are considered as makers or breakers of success.
www.shine.co.uk twitter.com/TomorrowsFM
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58
