English

In buildings growing conditions for mould fungi can occur and cause fungus infestation. Thepossible danger for the occupants of dwellings lies in the production and spreading ofpathogens (disease causing agents). Therefore, consequent measures have to be taken to avoidhealth dangers that result from mould fungi in buildings. A strategy has to be set up thatfocuses on the growth conditions for mould fungi and also considers the complex transientprocesses of building physics.

Novel indoor air purification technology using ions generated by discharge plasma has beendeveloped. The effect of ions on airborne influenza virus has been investigated by the plaquemethod using MDCK cells and the hemagglutination test. It has been discovered that theseions can inactivate influenza virus in air world first. The infection rate of influenza virus toMDCK cells has been drastically reduced with the use of ions generated by the developeddevice. Furthermore the efficacy tests of these ions for polio virus and coxsackie virus havebeen performed.

A novel indoor air purification technology using ions generated by discharge plasma hasbeen developed. With the application of AC voltage between electrodes, dischargeplasma has been occurred and positively charged ions and negatively charged ions havebeen generated at atmospheric pressure. The chemical compositions of the ions have beenclarified to H + (H2O)m and O2 (H2O)n by time-of-flight mass spectroscopy.Bacteriostatic and fungistatic effects of these ions have been investigated.

Microclimates in moisture chambers and environment in houses were evaluated using afungal index. The index was calculated from the growth rate of a sensor fungus in a test piece,fungal detector, during an exposure period to the test environment. In the constant climates inthe moisture chambers, higher indices were obtained at higher relative humidity. In the roomswith higher fungal indices, the densities of airborne fungi were higher, indicating arelationship between the index and fungal contamination.

This paper demonstrates the technical considerations that are important to understanding the energy-saving potential of encouraging the use of brushless direct current (BDC) motors in residential air handlers. Energy savings estimates are provided, and the regulations that are already in place are explained. Some misperceptions about the testing and operation of residential furnaces and air conditioners are also covered. Using one set of parameters that assume typical cyclic

The life-cycle assessment (LCA) methodology is used in this paper to assess the environmental effects of air-handling units (AHU) over a 20-year life cycle. This assessment is based on quantifying the consumption of resources (energy and materials), the harmful emissions into the environment (air, water, and soil), and the potential changes in the environment (climate change, acidification, and ozone production).

This paper shows how air-to-air heat and energy system design problems can be formulated for a simple HVAC configuration and solved for the least life-cycle cost system while still retaining a small payback period. Mathematical expressions and design tables are presented to facilitate the design process. The design process is illustrated for the city of Chicago where both large heating and cooling loads occur in HVAC applications. The example design problem presented shows that

This paper presents an integrated IAQ/HVAC simulation environment that can model the impact of contaminant-based demand-controlled ventilation (DCV) strategies on both indoor air quality and HVAC system energy use for multizone buildings. The predictions of the integrated IAQ/HVAC simulation environment are first validated against experimental data obtained from laboratory testing. Then the simulation environment is used to investigate the performance of three ventilation control strategies, namely: one conventional control using fixed-position for outside air damper and two

This paper examines thermal mixing of outdoor and return airstreams in typical air-handling units equipped with parallel blade dampers. The mixing of the two airstreams in rectangular and square mixing chambers is studied for eight different dampers and blade orientations. Testing is conducted at a total supply air of 16000 CFM with outdoor flow percentages of 15% and 30%. The temperature differential between the outdoor and return airflows is kept at 40F. Damper blades with chords of 4 and 6 inches are tested.

Field tests of stairwell and vestibule pressurization systems were performed in a 32-story high-rise building. Pressure differences in the stairwell, and vestibule and average air velocity were tested under various conditions. Test results indicate that indirect pressurization through a stairwell is feasible. Ignoring stack effect, the worst door-opening condition is that the fire doors of the top or bottom three adjoining floors of the building are open simultaneously. Pressurization systems in