Avoiding low frequency noise in packaged HVAC equipment

Journal Article · Tue Jun 01 04:00:00 EDT 1993 · ASHRAE Journal (American Society of Heating, Refrigerating and Air-Conditioning Engineers); (United States)

OSTI ID:6158967

Ebbing, C E ^[1]; Blazier, Jr, W E ^[2]

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1. Carrier Corp., Syracuse, NY (United States). Commercial Unitary Division
2. Warren Blazier Associates, San Francisco, CA (United States)

The purpose of this article is to help those involved in the design and commissioning of packaged HVAC systems to understand the root causes of low frequency noise problems and how to avoid many of them at the design stage. In the 1980's, two things happened to dramatically change the types of noise problems encountered in typical new construction. The first was the introduction of new energy regulations that favored variable air volume (VAV) distribution systems over constant volume air distribution systems. A by-product of VAV design is that mid- and high frequency sound pressure levels produced by current air terminal devices and diffusers in many applications are significantly lower than in the past. The second factor was a trend away from the use of built-up central station fan equipment in favor of packaged, floor-by-floor air handlers or rooftop units. As a result, today's HVAC system noise problems are not confined to just the roar and hiss of the past, but now include intense low frequency rumble and time modulation. Indeed, most current noise problems in modern buildings occur in the frequency range well below 250 Hz. A large fraction of these are a result of the dominant sound pressure levels in the 12 to 40 Hz region. These factors, combined with a substantial increase in the level of low frequency sound from the rest of the system, can produce a non-neutral, time modulated, rumbly sounding background noise that many people find objectionable.

• OSTI ID: 6158967
• Journal Information: ASHRAE Journal (American Society of Heating, Refrigerating and Air-Conditioning Engineers); (United States), Journal Name: ASHRAE Journal (American Society of Heating, Refrigerating and Air-Conditioning Engineers); (United States) Vol. 35:6; ISSN 0001-2491; ISSN ASHRAA
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320106* -- Energy Conservation
Consumption
& Utilization-- Building Equipment-- (1987-)
320107 -- Energy Conservation
Consumption
& Utilization-- Building Systems-- (1987-)
AIR POLLUTION ABATEMENT
BLOWERS
DUCTS
EFFICIENCY
ENERGY EFFICIENCY
ENERGY SYSTEMS
MECHANICAL VIBRATIONS
NOISE POLLUTION
PERFORMANCE
PLANNING
POLLUTION
POLLUTION ABATEMENT
SPACE HVAC SYSTEMS