It's 10:00 PM. Do you know what your building is doing? Is the economizer set to maximum outside air? Has the lighting control system, be it human or machine, switched circuits off in unoccupied areas? What percentage of your personal computers is running?
Increased building indoor air quality (IAQ) complaints due to reduced outdoor air ventilation rates led to ASHRAE Standard 62-1989. Even though the stipulated total outdoor ventilation flow rate may be drawn into the HV AC system, thermal imbalances in the various zones of the building can lead to certain zones being starved of the specified ventilation flow rate thereby creating localized IAQ problems.
Thermal distribution systems represent the most promising opportunities for cost-effective energy savings in residential new construction. This paper describes the results of an unusual but on-going collaboration between the building industry, the environmental community, the research community, and the regulators to develop cost-effective, implementable procedures for improved heating, ventilating and air conditioning (HV AC) duct system design, fabrication, and installation
Equivalent leakage areas (ELAs) of 50 Russian apartments were measured under three conditions: 1) as found, 2) exhaust vents sealed, and 3) vents, electric boxes and windows sealed, in 12 buildings of similar construction. Distributions of ELA per unit of apartment volume are presented for the three conditions. Apartment ELAs were found to vary slightly with floor, indicating that the level of occupant-applied weatherstripping is a function of occupants' perception of infiltration rates and that lower floor occupants perceive larger infiltration rates than upper floor occupants.
This paper reports on the ventilation measurements in a cinema using the tracer-gas technique. Both the local and room air exchange efficiencies were measured. The two tracer-gas methods, "step-up" and "step-down (decay)", were used alternately when the cinema was in use to enable a continuous measurement of air-exchange efficiencies under various occupancies. The air exchange efficiencies were found to be very close to that for a perfect mixing, with little influence from the occupants. This might be due to that the cinema had a downward mixing ventilation with a large air change rate.
The use of computers for simulating building thermal behavior started early at the Royal Institute of Technology in Stockholm, Sweden. The first example of such use dates from a 1957 study of an exterior wall exposed to solar radiation. The simulation program, later named BRIS, has gradually evolved with regard to the users and growing computer capacity. It has been used since the early sixties for research projects, design work and development of new systems, among others the ventilated hollow-core slab (Thermodeck) system.
As an introductory note, this aims to place the need for cooling for thermal comfort into the context of overall energy efficient building design. Additionally, it stresses the role of ventilation in meeting cooling requirements. Chapters are included on ventilation and cooling requirements; factors affecting cooling load; ventilation and cooling systems; and energy issues in ventilation and cooling, covering space cooling load, plant load and fan energy.