Improving ventilation in winter

We have a responsibility to advise businesses on proper ventilation throughout the year. We have therefore worked in collaboration with the University of Sheffield to develop guidance to support you and your employees.

Why is proper ventilation important

Spaces with poor ventilation have been shown to increase infections by nearly 50%. Improving ventilation in your venue can help to reduce respiratory infections.

This will keep your customers safe and has been shown to reduce staff sick leave by 35%.

How to improve ventilation

Use the short term options listed if possible, and work towards longer term changes.

Short term

You can put the following short term measures in place to improve ventilation:

• open high level windows, so the cold air mixes with the warmer room air before reaching people
• small or thin openings work well in winter, so cracking a window open is better than nothing
• if your windows don't open and if you only have larger openings, like your front door, use these for short periods to replace stale air with fresh air
• ensure you have a clear ventilation plan for when you will replace the air, and who is responsible for carrying out the plan

Medium term

CO2 monitors

Consider using a CO2 monitor to help you estimate your ventilation levels. This will allow you to adjust your ventilation to bring in the right amount of outdoor air, while minimising the impact on your heating bills.

On a CO2 monitor, values of 800 ppm or lower indicate good ventilation. Values of 1500 ppm or higher indicate you should improve ventilation. If the value is consistently above 1500 ppm, work towards the long term actions below.

A typical monitor can cost as little as £300, not including running costs.

Air cleaners

Where noise is an issue that prevents you opening a window, consider purchasing an air cleaner that plugs into the wall. Air cleaners that include a fan and HEPA filter are recommended.

Costs for an air cleaner system for a bar area of approximately 100 metres squared start at £2500, not including running costs.

Long term

Install mechanical systems, for example, wall mounted fans are easier to retrofit. Heat recovery systems are available and are recommended to reduce bills.

The typical cost for 100 people ranges. For example:

• £1500 for fans only (planning, installation and extras such as sound attenuation not included)
• £15000 for cheaper units are extract only, more expensive units provide heat recovery