The aim of that study was to find out if heating is the alternative for crawl space moisture control with a reasonable low energy consumption. Using a ground cover without thermal insulation and heating of the crawl space proved to be a good alternative method to control mold growth.

The aims of that study were to find out how the thermal capacity, resistance, and the placement of insulation layers affect relative humidity in crawl spaces. The results show that there are two alternative ways to use ground covers in combination with air change to achieve acceptable conditions in crawl spaces.

The aims of that study were on the one hand to find out how relative humidity can be reduced by optimal selection of ground covers and air change rates, and on the other hand to evaluate the acceptability of achieved moisture conditions by means of mould growth analyses. Two buildings (one relatively warm and the other relatively cold) were studied with the resistance-capacity network model. Simulations of thermal and moisture buffering effects of air change rates and various ground covers were made.

This paper describes the smoke control aspects of twonaturally ventilated high-rise office buildings with operable windows. One utilizes its operable windows in conjunction with an HVAC system to provide tenants with fresh air. The other utilizes a series of automatically controlled windows and
vents in conjunction with tenant-controlled windows to provide ventilation. Both buildings, located in San Francisco, were designed under the Uniform Building Code.

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