The majority of the Beijing National Stadium’s HVAC needs were supplied by Carrier, who supplied over 70% of the HVAC systems for the Beijing Olympics. The majority of the space is open-air, which eliminates the need for a great deal of HVAC systems withing the complex. It is also designed to allow a great deal of natural light inside the building, which reduces the cost of lighting.
Due to a lack of accurate plans of the building, quite a few assumptions needed to be made. The primary assumption was that each of the floors was identical, containing the same amount of occupied space, having the same loads. The calculations were also very generalized, and did not take into account the various exposure levels of each wall, the loads that electrical equipment would provide, or the effects of latent heating of the space.
The first calculation that was done was to estimate the perimeter of the exposed wall within the building. Since it is a stadium, much of the space is open-air, and is not conditioned. Using a map of the stadium, the retail spaces and restrooms were outlined, and using a drafting program, the wall perimeter was calculated. Each space had a perimeter of 122 feet, with twelve spaces per floor and six floors. That resulted in 44064 sq. ft. of exposed wall. Using that number, the BTU/hr going through the walls was calculated for both heating and cooling scenarios.
When calculating the annual cost for natural gas and electricity used, using a full calendar year would not be practical, since the space is not going to be used 24/7. Therefor, when considering heating loads, an 8 hour day, for 5 days a week was used for 5 months of heating, and 7 months of cooling, as this would be a typical work week. As this is a stadium, the actual hours of operation are most likely going to be less that what was estimated, but the estimate was still within reason.