Ventilation FAQs

Updated 15 December 2021

I am concerned that my teaching/lab room is not safe to use

All occupied spaces have been through a rigorous re-entry process which has included a check on ventilation provision.

Rooms with mechanical ventilation have been checked and systems have been altered to operate in accordance with government guidance and the Chartered Institution of Building Services Engineers (CIBSE) recommendations.

Their operating times have been altered so they come on earlier and run on beyond the occupation periods to purge spaces before and after occupancy, they operate with full fresh air (no recirculation of room air)  and controls are set to deliver the maximum volume that the air handling unit is capable of delivering.

Spaces which rely solely on natural ventilation have been checked to ensure the windows can be opened easily and have window stickers in place advising they must be opened when the room is occupied.

Ventilation is only one of a number of measures the university has taken to limit the opportunity for the spread of COVID, including reduced capacity in teaching spaces, setting seating at 1M, enhanced cleaning and hand sanitiser etc.

If a space has no identifiable means of fresh air provision it is restricted to single occupancy or taken out of use whilst remedial measures are identified and implemented.

What types of ventilation do we have in our rooms?

We have rooms with only natural ventilation (windows), rooms with only mechanical ventilation and rooms with both natural and mechanical ventilation.

My room has air conditioning is that the same as ventilation?

Air conditioning units heat or cool air but do not always provide fresh air. We have only opened spaces that have fresh air provision via mechanical ventilation or opening windows or both.

Is natural ventilation better than mechanical ventilation?

Opening windows will provide fresh air into a room, however they are subject to prevailing weather conditions and do not provide the consistently controlled level of air flow that a mechanical system does. The opening of windows also relies on the user to remember to do so. However both forms of ventilation can provide good fresh air and all staff should follow any local instructions about opening windows and not obstructing the mechanical vents.

If I can’t feel any air from the ventilation grilles does that mean its not working?

Not necessarily, mechanical systems provide a consistent air flow and when designed correctly it is not unusual for room occupants to feel no air movement (systems are designed to move air without causing discomfort). However as some mechanical systems are operating at enhanced rates some noise and draughts may be prevalent.

What do I do if I have concerns about the ventilation in my teaching space?

All rooms have been assessed for ventilation provision. If a space had no means of fresh air provision this has been restricted to single occupancy or taken out of use whilst remedial measures are identified and implemented.

Any concerns of stuffiness, stale air or other causes of concern should be raised through Estates helpdesk and will be investigated further.

I have been told I have to keep the windows open but this is making the room cold?

In the winter months, rooms which require open windows may become cooler than normal. It may be necessary for people to assess the conditions in their space and look to dress in warmer clothing during colder spells.

Windows should be closed when the space is not being used. Closing windows fully on exit will help to avoid heat loss overnight which can makes spaces very cold in the morning.

How wide do I need to open windows?

Spaces which rely solely on natural ventilation must have their windows opened when occupied however, in the winter, wind speed and air pressure are greater than in summer, therefore, ventilation rates are increased and the same size window openings can provide more fresh air.

Partially opening windows can provide acceptable ventilation while keeping workplace temperatures comfortable. Opening higher-level windows will create fewer draughts. There are a number of practical steps you can take:

  • Sit away from windows if the room isn’t full
  • Wear suitable layers of clothing to help control your own personal comfort
  • If the room starts to become cold, part closing the windows is possible but do not close them fully.

Do I need a CO2 sensor in the room?

CO2 sensors are not routinely installed into spaces as we have ensured that the space has good ventilation.

Estates Engineering and Health and Safety teams work closely with Faculty Building Managers to identify and understand any areas of concern and to decide if CO2 monitors would be useful in the circumstances. The placement of CO2 sensors can provide confirmation of continuing performance and reassurance in spaces where concerns are identified.

In some circumstances where concerns are raised in our naturally ventilated spaces, we may provide a CO2 monitor to provide further information. The CO2 sensor will provide a visual status with a numerical guide (CO2 levels are measured in Part per Million or PPM), together with occupant guidance to open windows as CO2 levels increase.

For mechanically ventilated spaces with CO2 controls, reassurance measurements will be undertaken through the controls system and monitored by the Engineering Team to support the agreed occupancy levels.

Spaces found to be consistently above an average of 1500ppm (800ppm for spaces where continuous talking or singing, or high levels of physical activity take place) will be reassessed for allowable occupancy levels and may be taken out of use whilst improvements are identified and implemented.