Computer Laboratory

Energy and Environmental

To date, the William Gates building remains the most energy efficient building in the portfolio of the University of Cambridge.

This is done by careful management and monitoring of the building management system which looks after temperatures throughout the building.

To help keep this system working at optimum, Building Services request that users of the WGB refrain from opening windows.

If you have any questions or need any clarification, please do not hesitate to contact Building services who will be more than happy to talk to you.

Where possible please do not open windows to control the temperature in your room, but use the climate control dial in your room. The heating and cooling, as well as the humidity in the air of your office, is monitored daily to make sure that the building is maintained at a comfortable temperature and to ensure the economic use of energy.

We are always happy to discuss the management of climate control around the building, and 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

Ventilation

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.

Heating

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 in a central machine room to a comfortable temperature (21 °C). Your window and outside office walls are highly insulated. The room temperature depends mainly on

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

If you have problems with the room temperature, and in particular before bringing in your own heater, get in touch with building-services.

Cooling

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 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

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.

Winter heating:Building Services have found that we can provide extra background heat from the Chilled Beams in the Winter, in a reversal of the way in which the Chilled Beams work during the Summer. An e-mail is sent out to the building-users list to let you know that the beams are running warm and that those who wish to take advantage of any extra heating can open the Oventrop Valve or move the control over to the blue setting. Instead of running at 14-16 degrees the beams run at 20-22 degrees during the winter months now. Don't forget to return the valve to its usual setting during the Summer.

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.

Lights

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 (datasheet) 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.

Windows

Windows are kept locked throughout the building in the interests of energy efficiency; for security on the ground floor and for safety reasons elsewhere. Open windows increase the heating or cooling demands of the building (provided by gas and electricity). Rising energy costs make it even more critical to ensure that the building is running efficiently.

All windows are equipped with blinds. Where these are not sufficient to protect a room user’s eyes from direct sunlight during some hours of the day, a second, opaque, blind can be installed. Contact Building Services if you need one.

If your room is too hot or too cold, then please let Building Services know so we can adjust the ventilation in your room to your needs.

Why windows should remain closed

The reason why we like to keep windows closed at the William Gates Building, is to conserve energy. The Building Mangement System, which controls the climate in the Building, helps with this aim:

  • warm air is blown into your room via the floor vents
  • cool air is generated by use of the chilled beam control (Oventrop valve) on the wall next to the light switch in your room
  • both of these are adjustable

With these control systems in place, you can perhaps begin to understand how opening a window open for long periods of time while the building is heating in the winter, or cooling in the summer, would lead to a huge waste of energy.

The Building Management System (BMS) is also adversely affected by the false indications given by the temperature change taking place when a window or outside door is left open. Such false indications of temperature can change the settings for heating/cooling for up to three working days, so you can understand why the windows are now kept closed.

If you wish to change the temperature in your room, please talk to Building Services who can make adjustments to the way in which your office is ventilated thus keeping you comfortable in your working environment.

Computers

A large fraction of the energy consumed in our building powers our IT infrastructure. Therefore, where possible, computing infrastructure should be turned off when not in use.

In particular, desk computers should be switched off or sent into a hibernation mode when not used (especially overnight), and their displays switched off. 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.

Recycling

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).