The impact of windows on residential energy use.

The goal of this work is to better understand the influence of window U-factor and solar heat gain coefficient on residential space heating and cooling energy use in the United States. We calibrated our simulation models with residential energy use data and evaluated the affect of window U-factor and solar heat gain coefficient on space heating and cooling energy use. U-factor and solar heat gain coefficient have a comparable impact on heating energy use, whereas U-factor has a minor impact and solar heat gain coefficient has a strong impact on cooling energy use.

Ventilation, humidity, and energy impacts of uncontrolled airflow in a light commercial building.

A small commercial building was monitored before and after energy-saving retrofits to study the impact of retrofits upon ventilation rates, humidity, building pressure, and air-conditioning energy use. Duct airtightness testing identified severe duct leakage as a significant source of uncontrolled airflow. Differential pressure and infiltration measurements using tracer gas indicated an attic exhaust fan as another significant source of uncontrolled airflow. Duct repair resulted in a 31% drop (30.5 kWh/day) in cooling energy and an increase in relative humidity from 72% to 76%.

Design for smoking areas: Part 2 - applications.

Recent ASHRAE forums have revealed an increased interest in information and guidance relative to designing and applying ventilation systems for areas where smoking is permitted. There are few data currently available through ASHRAE for the engineer challenged with designing a cigar bar, a smoking lounge, or a bar or restaurant with smoking permitted. This paper applies laboratory data about the acceptance of environmental tobacco smoke to real-world applications.

Design for smoking areas: Part 1 - Fundamentals.

ASHRAE currently provides little practical information for optimizing the design of a cigar or smoking lounge, although recent ASHRAE forums have indicated an increased interest in this area. This paper provides a summary of the measurement of environmental tobacco smoke (ETS) from cigarettes or cigars, the manner in which ETS concentration varies with rates of smoking and ventilation, and the relationship between ETS concentration and indoor air quality.

Contaminant and heat removal effectiveness and air-to-air heat/energy recovery for a contaminated air space.

Measured contaminant and heat removal effectiveness data are presented and compared for a 3: 1 scale model room, which represents a smoking room, lounge, or bar with a two dimensional airflow pattern. In the experiments, heat and tracer gases were introduced simultaneously from a source to simulate a prototype smoking room. High-side-wall and displacement ventilation schemes were investigated, and the latter employed two different types of ceiling diffuser, low velocity slot and low-velocity grille.

Numerical simulation of contaminant distribution around a modelled human body: CFD study on computational thermal manikin - Part II.

The rising stream around a human body attributable to metabolic heat can carry contaminants from the floor level to the human breathing system. Thus, the quality of the breathing air greatly depends on the concentration distribution in the lower part of the room and the characteristics of the local air motion around the body. In this paper, a modeled human body (computational thermal manikin) is placed in a room that is air-conditioned with a displacement ventilation system.

Numerical simulation of the air conditioning environment in a computer room.

This paper describes the development of software for simulating the air-conditioning environment in a computer room. This software uses a finite volume method combined with a rectangular structured mesh system and a k-£ two-equation model for turbulence. Some special modeling techniques are also used. This software has two purposes: (1) to optimize the layout of a computer room, thus minimizing the electric power used for air conditioning, and (2) to reproduce the situation in which an accident is caused by an air-conditioning problem and to assist in an investigation of the problem.

T-Method duct design, Part V: duct leakage calculation technique and economics.

The procedure of incorporating duct leakage into the T-method simulates leakage as an additional parallel section with zero length for each duct section. The assumption that additional air leakage creates additional system resistance is wrong. Leakage always reduces, not increases, system resistance. How fan power consumption changes due to leakage depends on the fan performance curve.  Methodology was developed to add duct leakage to the T-method previously developed for both the design and simulation of duct systems. It is shown that in most cases the sealing of ductwork is economical.

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