Department of Computer Science and Technology

Energy and Environmental

The William Gates building aims to be an energy efficient building.

To optimise energy efficiency, Building Services request that, where possible, users of the WGB refrain from opening windows. If you do need to open your office window, please ensure that your door is kept closed whilst it is open. Please do not leave your window open overnight, or while the office is not in use.

Where possible, use the climate control dial in your room to control the temperature. If you require any further information, please contact Building Services, who will be happy to discuss this issue and answer any questions you may have.

Climate control


Offices are supplied with fresh air through round metal vents in the floor. Air leaves an office via a rectangular hole on the wall leading to the corridor ceiling void. Air that has passed through an office leaves the building and is not recirculated (except perhaps when the outside temperature is very low). The heat of the outgoing air is recycled through a heat exchanger.

Air flow can be adjusted per building section, as well as in individual floor vents. If you believe that any adjustments are necessary, contact building-services.


Each office has a large radiator ("chilled beam") along the wall by the door, which is suspended from the ceiling and covered with a white box. It is connected via a thermostatic valve to the building's chilled water system. This radiator can only cool, not heat the room. It is mainly intended for use in rooms with a large number of computers or where there is too much solar gain over the summer months.

The amount of chilled water flowing through the radiator is controlled by the adjustable thermostat that is located next to the door and the light switch. Its settings are:

5chilled water flows if room > ~28 °Cwarmest setting
4chilled water flows if room > ~24 °Crecommended
3chilled water flows if room > ~20 °C
2chilled water flows if room > ~16 °Ccoolest useful setting
1chilled water flows if room > ~12 °Cbelow water temperature
*chilled water flows if room > ~7 °Cbelow water temperature
0chilled water flows alwaysonly for testing

If you prefer to ventilate your office by opening the window, please ensure the cooling valve is set to 5 (red dot).

With electrical heating: In rooms that have an electrical heater installed, make sure that the cooling thermostat is closed by setting it to 5 (red marking) when the electrical heater is on. This is to avoid heating and cooling simultaneously and thereby wasting a lot of energy.

Details: The thermostat appears to be an inverted (cold water) version of the oventrop Uni FH with remote control. The above approximate temperatures come from the manufacturer's installation instructions. The dots between numbers 2 and 4 correspond to a temperature difference of 1 °C.


Most offices have no individual heating mechanism; a few corner rooms have wall-mounted electric heaters. The air pumped into the floor space is heated to 21 °C. Your window and outside office walls are highly insulated. The room temperature therefore depends mainly on:

  • the temperature and flow rate of air from the floor vents and/or open windows
  • power dissipated by electrical devices (computers, lamps)
  • solar gain
  • the setting of the cooling thermostat

To reduce solar gain in the summer, please use the blinds. If you have problems with the room temperature being too low, please do not bring in your own heater. Instead, please get in touch with building-services to discuss the problem.


The ceiling lights are equipped with a light sensor located in a small white cylinder at one end of the fitting. They can be adjusted such that the reflected light level seen by the downward-looking phototransistor remains roughly constant. A correctly adjusted sensor helps to save energy. If you believe that your lamp needs adjustment, please contact building-services. If the light malfunctions, the electronic ballast may have to be replaced (we had a series of early failures with these).

In some areas of the building (not offices), a passive infrared detector switches the lights on and off based on occupancy and ambient light. It comes with a manual override button:

  • If the lights are on, using the override will turn the lights off permanently until the override button is pressed again.
  • If the lights are off (because of the ambient light), use the override to turn the lights on. The lights will remain on until the occupancy period is over.


A large fraction of the energy consumed in our building powers our IT infrastructure. Therefore, where possible, computing infrastructure should be set to hibernate or low power mode when not in use. Lab-managed machines are already set up in this way, so no future action is required.

Avoid animated screen savers. If you prefer to leave your computer on to access it remotely, please consider the following alternatives:

The sys-admin wiki features an energy-saving page with more detailed suggestions.


As of April 2011, all waste discarded by the Computer Laboratory is brought to a central recycling site, where it will be sorted.

  • Paper can be discarded in collection points next to the printers, but can also be disposed of in normal office bins.
  • Glass jars and bottles, cardboard and any general waste can all go into office bins.
  • Soft-drink cans and shredded paper will be collected in the same way but with a clear plastic liner in the bin.
  • Food waste must be separated and put into the correct bin in the kitchens.
  • Batteries, toner, IT equipment, and light bulbs are collected separately at Stores (GW03).