The purpose of continuous fan operation is to bring in fresh outdoor air to the conditioned space in order to maintain acceptable indoor air quality. Ventilation not only uses more energy, but it also impacts air distribution system efficiency.This is partially due to various system interactions. The objective of this paper is to quantify the impact of continuous fan operation on energy use and distribution efficiency by introducingtwo new parameters: energy use ratio (EUR) and distribution efficiency ratio (DER).
Recently indoor air quality (IAQ) became an important issue and as a result researchers have developed a large number of different air quality indicators. This study focuses on air exchange efficiency (ea) and contaminant removal effectiveness (e) as suitable indicators for use in design and on-site measurements. These two IAQ indicators were numerically studied and compared for five typical indoor spaces with different ventilation strategies and contaminant sources. Overall,
Past research that has evaluated the association between student performance and some change variable (building renovation, room temperature, curriculum, teacher involvement, etc.) has focused on student-level data and has not adequately accounted for regression artifacts (regression to
The interior zone and exterior zone air-handling units (AHU) can be connected through their return air ducts to become a new air-handling unit system, named OAHU system, which allows optimal choice of outside air intake and decouples sensible and latent cooling in a zone with lower sensible
This research evaluated the effectiveness of local supply ventilation in controlling air quality at or near workers’ breathing zones in livestock confinement buildings. Commercially available ceiling (box-type) diffusers and local supply ventilation syste
For energy savings, DCV systems are more and more used on ventilation systems. In France, in non residential buildings, these systems are generally controlled by either a CO2 sensor, or an optical movement detection (infrared). To achieve correct performances, pressure conditions in duct and fan regulation must be considered.
Every city or town has a market to supply fresh food to its residents. A market has the function of displaying fresh food, auctioning it, and supplying it to consumers. A market must fulfill this role throughout the year even in cold, snowy areas, and this calls for a large, covered space. At the same time, vehicles of various sizes drive in and out of the market premises to transport food into and out of the market. These vehicles emit exhaust gas, however, and the introduction of a large amount of fresh air into the market space is indispensable for maintaining good air quality.
We designed a roofed parking lot for a large wholesale market in Sapporo City to protect trucks and cars from snow and rain. Every day, the area attracts a large number of vehicles including trucks. Drivers often leave the engines running for heating in winter and cooling in summer. Exhaust gases poison the air, creating a serious environmental problem. The roof of the new parking lot is equipped with two kinds of chimneys, such as high chimneys to exhaust waste air and low chimneys to supply fresh air.
The annual energy cost and first cost of the HVAC system, life-cycle costs (LCC) and benefits of improved productivity were simulated in an office building located in a cold climate when improvements of air quality were made by increasing the outdoor air supply rate and by reducing the pollution loads. The building was ventilated by a variable air volume (VAV) system with an economizer or a constant air volume (CAV) system with heat recovery. The pollution loads were assumed to be similar to those in a non-low-polluting or low-polluting building.
This paper describes a study of reduced performance of mechanical exhaust systems in 42 Dutch houses after several years of operation. It also describes the effect of reduced ventilation on air quality and the perception and use of the ventilation system by residents. The guanine contents of dust samples taken from the sleeping room were determined to assess the risk of allergy.
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