Why have ventilation in offices? We have been asked this a few times and there are actually several reasons. The question is more important at the moment with the current Covid 19 pandemic as people are worried about being inside enclosed spaces without ventilation.
Although this issue has been brought to many peoples attention, fresh air in offices is actually a legal requirement in order to comply with Building Regulations.
When we carry out refurbishment projects that affect fire escape routes, general fire protection separation in offices and warehouses we have to submit plans to Building Control to get approval. Part of the things they look for is in Part F which relates to ventilation and there is a required to supply a certain rate of air in litres per person. We therefore have to calculate the correct size unit for the number of people.
What about Windows?
Most offices have windows. In theory you could argue that as the office has windows it has fresh air ventilation so does not need any mechanical method of delivering it. How many people have the window open though? Particularly in winter when there is a howling gale outside as well as raining horizontally. People are just not going to open them. The best way to ensure that you have fresh air is to have a proper VAM unit installed.
Although we can focus on C02, as well as being easily measured with a meter, there is an actual impact on people in terms of their performance if the C02 levels are too high. C02 is carbon dioxide and is a by product of combustion. Humans produce it when they breath.
Carbon dioxide levels and potential health problems are indicated below:
- 250-350 ppm: background (normal) outdoor air level.
- 350-1,000 ppm: typical level found in occupied spaces with good air exchange.
- 1,000-2,000 ppm: levels associated with complaints of drowsiness and poor air
The effect on office staff when C02 levels are above 1000 ppm cannot be under-estimated. If your office feels stuffy and there is a general lethargy in the mid afternoon where everyone needs more coffee and less is produced, there is probably not enough fresh air in the space.
Opening a window is good, and will create a difference but this is not always possible. In order to get the correct flow rates, and ensure that the air is filtered then a VAM unit needs to be fitted.