InspectAPedia®   -   Search InspectApedia

Ceiling whole house fan system (C) Daniel FriedmanBuilding Fan Noise Troubleshooting
Diagnose, & cure air exhaust fan, vent fan or other bulding fan & motor problems

  • POST a QUESTION or COMMENT about diagnosing the source and finding the cure for noises or sounds in or around buildings and their systems

Building fan or fan motor noise troubleshooting: causes & cures.

How to diagnose & fix noises traced to fans used in building ventilation systems, air condtioners, heat pumps, furnaces, kitchen or bathroom vents or other locations.

These articles discuss building noise control: how to inspect, diagnose & cure noise or sound problems in homes or commercial buildings.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Sources of Fan Noises in Buildings & How to Control Fan Noises

Bathroom ceiling vent fan, heater, light combination (C) Daniel FriedmanBuilding fans are used for indoor air quality (whole house fans, attic vent fans, air to air heat exchanger fans, bathroom and kitchen vent fans).

Normal fan and vent noises

originating in the vent fan motor and the noise of air movement through the vent are measured in sones. A residential exhaust fan that is left on constantly and that runs at 400 CFM or below, should operate at a noise level of 3 sones or less.

Abnormal fan noise sources

include noises traced to fan motors (humming, rattling) or mechanical components such as a loose fan blade (ticking, rattling, banging) as well as possible electrical hazard noises (unsafe wiring or motor defects, hissing, etc.)

Usually if there's a noise complaint blamed on or thought to be originating at a fan or blower assembly we already suspect a specific fan, but don't rule out building noises traced to a variety of fan assemblies including

Fans used for building ventilation: attic exhaust vents, whole house ventilation systems, fans in appliances such as clothes dryers, microwaves and ovens or refrigerators, bath or kitchen exahust vent fans, continuously operating fans such as crawl space vent systems and radon mitigation system fans, and of course fans used in the air handler of heating and air conditioing air handlers.

There's also a fan inside of oil burners and in direct vent exhausted oil or gas appliances, and there may be a draft inducer fan on some heating equipment chimneys.

Fan or blower noises on heating and air conditioning systems may include ticking or clicking (fan blade hitting an obstruction), humming (motor troubles), rattling (loose fan pulley), squeaking (dry fan or fan motor bearings) and other sounds.

Air conditioner and heat pump systems use fans both in the indoor air handler (the blower fan) and outside at the compressor-condenser unit.

List of Sources of Noises Originating in a Blower or Fan

Electrostatic air cleaner at an air handler (C) Daniel Friedman at InspectApedia.comA fan motor or assembly that's having trouble and even a fan that is operating normally can create a varity of noises including the following:

How to Convert Sones to Decibels or phones

1 sone = 40 dB or 40 phones, but

Watch out: the dB scale is logarithmic, not linear.

Conversion table: Sones to dB or phones

Sones dB /
Decibels /
Phones
0.06 (Hearing threshold) 15
0.25 25
0.44 (Whispered speech) 30
0.5 (Rustling leaves) 32
1 (Typical refrigerator) 40
1.4 (Typical dishwasher) 45
2 50
3 (Typical office noise level) 55
3.5 (Moderate dishwasher noise) 58
4 (Normal conversation) 60
7 (1200 CFM Modernaire floor fan on high speed) 68
8 70
9.2 (Typical vacuum cleaner) 72
16 80
32 (Typical lawnmower) 90
64 (Typical leaf blower or power saw) 100
128 110
256 120
724 (Jet plane takeoff) 135
1024 (Police siren at 100 ft.) 140

Notes to the table above

Watch out: noise levels over 82 dBA require hearing protection if you are withing 5 ft. of the noise source

ISO 532-2:2017 specifies a method for estimating the loudness and loudness level of stationary sounds as perceived by otologically normal adult persons under specific listening conditions.

It provides an algorithm for the calculation of monaural or binaural loudness for sounds recorded using a single microphone, using a head and torso simulator, or for sounds presented via earphones. The method is based on the Moore-Glasberg algorithm.

DIN 45631 Procedure for calculating loudness level and loudness

Formula to convert Sones to dBA

x sones = 10 log2 x + 40 phons or dBA

Formulat to convert dBa or phons to Sones

2(x - 40)/10 sones

Fan Noise Standards

Noises from Fans & Venting Equipment in Other Building Locations

Ceiling whole house fan system (C) Daniel FriedmanVentilation fans used in baths, kitchens, air to air heat exchangers, whole house ventilating fans, attic vent fans, gable end vent fans, and fans used in small appliances such as microwave ovens, even stereo systems can produce hums, clicks, and rattles as well.

To help separate normal fan operating noise from noise indicating trouble you'll want to read our discussion of fan noise level ratings measured in sones.


...

Continue reading at AIR LEAK NOISES in BUILDINGS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

Suggested citation for this web page

FAN NOISES in BUILDINGS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING NOISE DIAGNOSIS

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification
when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Comment Form is loading comments...

Citations & References

In addition to any citations in the article above, a full list is available on request.



ADVERTISEMENT