With today’s tighter building envelopes, it is imperative that builders and contractors stay up to date on industry standards for ventilation systems in order to ensure good air quality inside the home. Longer duct runs and multiple elbows increase static pressure, which can reduce airflow. ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) has set the industry standard for ventilation performance measurement at 0.25" water gauge for airflow. To meet this standard, Panasonic Home & Environment Company has introduced its third-generation WhisperGreen® line of premium ventilation fans.
23 30 00 HVAC Air Distribution
Air distribution refers to the distribution of air to and from conditioned spaces within a building. An air distribution system includes all sub-components, such as fans, filters, dampers, ductwork, etc. Air distribution systems come in a variety of material types, for example, fiberglass and galvanized metal. In fact, many different kinds of ducts may be found in a single air distribution system.
Fire dampers are dampers which are forced to close in the event of a fire. There are different kinds of fire dampers, and they are classified according to the following factors: how they are actuated or forced to close; the physical constraints of their installation; and the fire rating of the ceiling, floor, or wall being penetrated.
A variable-air-volume unit, or VAV box, as they are commonly called, is part of an air conditioning system. It is a device installed in the supply ductwork which regulates the volume of air being delivered to a zone. A zone is a defined space that is governed by a single thermostat or sensor, and for which there is a main supply duct that subdivides into as many ducts as are required to fully air condition the zone’s spaces. The device itself regulates the air passing through it by opening and closing a damper, and it can vary the quantity of air which passes through it. As the thermostat senses the need for more air conditioning, it signals the VAV to open the damper, and vice versa.
This topic covers information related to dampers installed as part of HVAC systems during construction. Volume control dampers can be installed inside a duct or as part of a register or diffuser. They are adjustable devices that control the volume of air provided to a specific location within a structure. Smoke and fire dampers are installed inside a duct located in a firewall. They are automated devices that close to prevent the spread of fire.
This topic covers information related to flexible ducts installed as part of HVAC systems during construction. Flexible ducts are round in shape and can be made from plastic with glass wool insulation over metal coiled wire.
This topic covers information related to HVAC fans installed as part of HVAC systems during construction. HVAC fans can be one of several types; axial, centrifugal, power ventilators or air curtains. Axial fans in construction are commonly known as ceiling fans. Centrifugal fans are commonly found in mechanical units that distribute air. Power ventilators are used to draw air from a room or portion of a structure and remove heat and/or moisture, such as attic vents and gable vents. Air curtains are stand alone devices that generate a wall of air that separates two spaces, such as an entry from the outdoors to the indoors.
This topic covers information related to air terminal units installed as part of HVAC systems during construction. Air terminal units control or modify the amount and temperature of air being distributed to a specific zone in order to achieve a desired comfort level within the space. Air terminal units are either a constant or variable volume systems.
This topic covers information related to diffusers, registers and grilles installed as part of HVAC systems during construction. Diffusers, registers and grilles are finish elements of an HVAC system where air is supplied or removed from a space or building.
This topic covers information related to kitchen hoods installed in commercial kitchens during construction. Commercial kitchen hoods exhaust air to remove contaminates, provide make-up air to ensure adequate indoor air quality and where required have an integrated fire suppression system.