Evaluation of residential duct sealing effectiveness.

The purpose of this project was to evaluate duct sealing as a means of reducing the energy consumption of hot air distribution systems in central Pennsylvania houses. Five houses were studied, all of which were heated with forced-air electric heat pump systems. During the winter of 1995, the heat pump energy consumption, supply air temperature, and the temperature at the thermostat were monitored continuously for approximately two months prior to the duct retrofit. A test also was performed to measure the leakiness of the ductwork.

Residential field testing of an aerosol-based technology for sealing ductwork.

Research over the past five years has indicated that a significant majority of the cost of residential retrofit duct sealing is in the labor required to find and seal those leaks. This paper describes the results of a field investigation of the performance and practicality of sealing residential duct leaks from the inside by means of a technique based upon injecting a fine aerosol spray into the duct system. The field results presented are from 4 7 houses located in Florida.

Field comparison of design and diagnostic pathways for duct efficiency evaluation.

A new method of test for residential thermal distribution efficiency is currently being developed under the auspices of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). This test method will have three main approaches, or "pathways," designated Design, Diagnostic, and Research. The Design Pathway uses builder's information to predict thermal distribution efficiency in new construction.

The sound of silence.

As active noise control systems begin to penetrate the market place, are the days of the passive attenuator numbered? Andrew Brister looks at the likely future for anti-noise.

Fan and ventilation duct noise in submarines.

Fans and their associated ventilation ducts are amongst the major sources of airborne noise encountered within a submarine. Health & Safety Standards require that the ship's crew are not exposed to unnecessary high levels of noise and have a suitable environment free from intrusive noise in order to work and rest. The problem with noise emitted from fans and ducts in submarines can be categorised as follows:

Can a new duct test take the pressure?