Indoor air quality ventilation airflow rates and HV AC capital and operating costs usually are closely related. Auxiliary energy loads for supply air heating or cooling sometimes can substantially reduce the need for dehumidifying or humidifying by using air-to-air heat or energy exchangers. The most important factors in reducing HVAC capital and operating costs are ventilation airflow requirements, climatic parameters, exchanger recovery system performance factors and duration of operation.

A Japanese electronics company has developed a new type of gas-to-gas heat exchanger, called the Ductron. The heat exchanger has a simple structure composed of aluminium or stainless steel pass partition plates stacked with a gas passage (1 cm wide) between each plate, Heat exchange duct- Ductron and can be installed as part of an air duct system. It is applicable not only to HVAC systems but also to various industrial applications. The efficiency level is over 5 0%.

MJM ACOUSTICAL CONSULTANTS INC. has been retained by the CANADA MORTGAGE & HOUSING CORPORATION to conduct a research project on the noise isolation provided by access doors in multi-dwe.lling buildings. A total of nine Sound Transmission Loss (TL) tests were conducted on four 1 3/4" doors (one wood door and three metal doors) and one 2 1/4" wood door. This research project has also been used as a preliminary attempt to validate a simple method to m. easure the Sound .T ransmission Loss and. Sound Transmission Class of a door when it is installed on site.            

This Update presents guidelines for controlling the transmission of impact sound through concrete-slab and wood-joist floor systems in multi-family dwellings. It is based primarily on industry-supported research conducted by IRC.