What is a set-point?
The set-point is the agreed temperature that the building will meet and is usually included in lease conditions. The typical ‘set-points’ are 21–22°C in winter and 23–24°C in summer. However, for every 1°C adjustment of the air-conditioning closer to the outside temperature, the energy required for heating and cooling is cut by 5–10%.
The feeling of an office being freezing in summer and stuffy and hot in winter means that the set points may not be optimised and the building is working a lot harder than it needs to in providing those temperatures.
Research in the field of indoor comfort is showing that lower winter temperatures (20°C) and higher summer temperatures (up to 25°C) can maintain comfort levels acceptable to most occupants, depending on other aspects of the building, relative humidity and the occupants’ tolerance levels. More flexible or ‘floating’ set points could be negotiated between tenants and facilities managers, potentially forming part of green lease conditions or through other channels.
Notes for building owners
Some premium office managers do a lot of work in maximising their heating and cooling efficiency. There are a number of resources to assist in both technical areas and the tasks that require education and behaviours for tenants for the sector. The Commonwealth Government’s Energy Efficiency Exchange is a good place to start for an overview of this topic.
A talk by Prof. Richard DeDear at the Sydney Better Buildings Partnership Green Leasing event explains the complexities of occupant comfort for building operators.