Potential of savings for demand controlled ventilation (DCV) in office buildings

For energy savings, DCV systems are more and more used in ventilation systems but toestimate their energy savings, variation of occupation in the building (in time and number ofperson) must be estimated. We have enquired on real occupation on site in 27 offices and 13meeting room in France. Occupation rates have been monitored either by webcam or byenquiry to the users. Results show very low occupation rates in meeting rooms although mostpeople feel they are very occupied. Yet effective time of meetings and number of occupantsare less than expected.

Passive cooling in a low-energy office building

Natural night ventilation and an earth-to-air heat exchanger are applied in the low-energy office building ‘SD Worx’ in Kortrijk (Belgium). Temperatures measured during summer 2002 are used to discuss the operation and cooling effect of these passive cool

Natural ventilation for office buildings cooling

In the 1990's, concern about global warming has resulted in a resurgence of interest in naturally ventilated offices. The Belgian climate is particularly well adapted to apply cooling by natural ventilation. Indeed, except for a few hours a year, outdoor air temperature is lower than indoors. Lots of office buildings have no atrium or chimney to benefit from any stack ventilation. But natural ventilation can nevertheless be organized with only frontage windows either by single-sided ventilation or by cross ventilation.

Integrated systems demand control technology

The peak electrical demand of office building VAV systems will be reduced by about 1.2 Kw/1000 Ft2 by employing an Integrated Systems Demand Control Technology (ISDCT) sequence to reduce peak intake flow by about 56%.Supply, return, and exhaust fan energy decreases with reduced airflows and pressures; and chiller system energy is saved by reduced cooling coil loads.The ISDCT sequence continuously computes zone contaminant concentrations allowing compliance with reference standards.

IEA ECBCS Annex 36 : retrofitting in educational buildings - REDUCE 25 case study reports from 10 different countries

The IEA ECBCS Annex 36 deals with the energy retrofit of educational buildings. Researchers from 10 participating countries from Europe and the US are collecting information on retrofit measures and case studies and are developing an energy concept adviser for technical retrofit measures. This internet-based computer tool for decision-makers is the main outcome of the annex. One of the most important inputs to the tool is the collection and assessment of case studies, which is also presented in a specific report.

Hygrothermal behaviour of a humidity controlled air inlet

This paper deals with the real behavior of a humidity controlled air inlet, regarding to relative humidity and temperature. It has been often heard, that relative humidity is not the best indicator for detecting a need of ventilation in main rooms (living room and bedrooms) because it is season dependant (the absolute humidity outside varies in a wide range from winter to summer, which should lead the air inlet to be closed in winter and open in summer).

Humidity control in offices in the Belgian climate

In the survey study ‘Kantoor 2000’ the HVAC-system of several large office buildings in Flanders was monitored. Some of these buildings use air humidity control, most of them not. This triggered the question : why? In this paper the humidity control strat

Dynamic buffer zone - Controlling moisture and heat flow

The building envelope is primarily an environmental separator, which allows indoor spaces to bemaintained at different conditions from the outside environment. Intentional humidification during the heating season is a common practice in cold climates. Moisture escaping from a humidified building due to air leakage through flaws in the air barrier system can negatively affect the durability of the building envelope.

Directional airflow performance of ventilators for natural ventilation

The use of natural ventilation systems continues to be a popular feature in low energy, sustainable building design. One feature of natural ventilation is that, depending upon the prevailing climatic or thermal conditions, the airflow through a ventilator can be bi-directional. Aerodynamically, the ventilator, depending upon its construction, may not perform in the same way for the two different flow directions.

Development of indoor climate classes to assess humidity in dwellings

The knowledge of indoor air humidity in the design phase is important to decide on the appropriate moisture control measures to prevent moisture problems in building components. Because of the uncertain nature of most of the factors affecting the indoor humidity, its accurate prediction in the design phase is not possible. To overcome this problem, the concept of Indoor Climate Classes has been introduced and used in Europe since its early development in the Netherlands in the 1970s up to its recent introduction in a European Standard on the hygrothermal performance of building components.