Imposing limits on summer set-points in UK air-conditioned offices: A survey of facility managers

Various countries have introduced minimum cooling set-points for air-conditioning either through voluntary or mandatory policies. In the UK, recent recommendations advocate higher summer thermostat settings in offices than formerly, with an indication that 24±2 °C may deliver thermally comfortable environments. However, limited published information exists on the actual summer temperatures maintained in UK air-conditioned offices and on facility managers' perspectives on imposing limits upon summer set-point (SSP). To address this knowledge gap, an online survey was distributed to facility managers responsible for temperature regulation in UK air-conditioned offices. Over 60% of the respondents report a SSP≤22 °C, indicating potential to raise SSPs. Responses indicate that a recommendation is preferred to a mandatory approach in limiting SSPs, although a mandatory policy is acknowledged as a potentially more effective driver of change. Whilst a mandatory policy on SSP limits may not be welcomed by FMs and would be difficult to enforce, public sector organisations could lead the way in introducing minimum SSPs, as they generally implement higher SSPs than private organisations, are more supportive of such a policy and would accept higher SSPs. Further intervention studies are required to assess the impact on occupants' expectations and productivity, along with senior management's perceptions.