【正文】 adjust the fort in their space. Improper temperature, humidity, ventilation, and indoor air quality can also have significant impacts on productivity and health. When we are thermally fortable we work better, shop longer, relax, breathe easier, focus our attention better. In order to provide a fortable and healthy indoor environment the building mechanical system must: Provide an acceptable level of temperature and humidity and safe guard against odours and indoor air pollutants. Create a sense of habitability through air movement, ventilation and slight temperature variation. Allow the occupant to control and modify conditions to suit individual preferences. Resistance to building management systems and intelligent buildings technology Our buildings are already energyefficient. (Is the whole building energyefficient, or is the landlord limiting his focus to mon areas and gross leased spaces?) We prefer the equipment with the lowest first cost when fitting out tenant space. (Does the specifier have any idea who will bear the increased operating costs of such a strategy?) We need a twoyear simple payback or less. (Is this still realistic, given that the percentage return on money markets is literally onetenth what it was 20 years ago?) Tenants pay all energy costs, and will get all the savings. (Do tenants really pay all energy or just the energy over a preset base year or expense stop?) We39。 can make people happier, healthier, and more productive. And with the reduced need for electric light, a great deal of money can be saved on energy. Nearly every mercial building is a potential energy saving project, where the electric lighting systems can be designed to be dimmed with the availability of daylight. Up to 75% of lighting energy consumption can be saved. In addition, by reducing electric lighting and minimizing solar heat gain, controlled lighting can also reduce a building39。 improved systemsdesign userfriendliness, and the provision of relevant instructions and information are all critical to enable theory to translate into practice, and for potential effectiveness and savings to be realised. Building management systems and intelligent buildings practical benefits Energyeffective systems balance a building39。s (passive infrared sensors), and manual user control. Lighting control methods Different control systems exist, again timebased control and optimiser parameterbased where a level of illuminance or particular use of lighting is required. Zones: lights are switched on corresponding to the use and layout of the lit areas, in order to avoid lighting a large area if only a small part of it needs light. Time control: to switch on and off automatically in each zone to a preset schedule for light use. Passive InfraRed (PIR) Occupancy sensing: In areas which are occupied intermittently, occupancy sensors can be used to indicate whether or not anybody is present and switch the light on or off accordingly. Light level monitoring: this consists of switching or dimming artificial lighting to maintain a light level measured by a photocell. Building management systems and intelligent buildings energy savings Until recent years, energy efficiency has been a relatively low priority and low perceived opportunity to building owners and investors. However, with the dramatic increase and awareness of energy use concerns, and the advances in costeffective technologies, energy efficiency is fast being part of real estate management, facilities management and operations strategy. The concepts are also now making significant inroads into the domestic