Soundproofing your HVAC system is one of the most confusing parts of soundproofing and one many of my students always have questions on. In this article I will demystify how to soundproof your HVAC system and give you some concrete principles that will help you with your design.
1) Increase Duct Size
The number one way to ensure you don't hear the air coming into your soundproof room is to make sure that your ducts are big enough, so that the air moves slowly through them. The goal is to have the speed of the air between 300-100 FPM or Feet Per Minute.
Let's look at an example. If you ventilation system is pushing out 100CFM or Cubic Feet Per Minute then you would want a 1 foot by 1 foot duct to get the speed of the air to 100FPM.
2) Right Angle Bends Introduce Noise
When your duct work makes a right angle bend it introduces turbulence which leads to air noise in your duct system. To reduce this try keeping your right angles at least 5-10 meters or 16-32 feet from your exit registers. If this isn't possible then just keep them as far away as possible. You can also use silencers to reduce the noise in a vent.
3) Use Round Ducts
Rectangular ducts create more turbulence and noise in the duct system. It is best to stick to round non-rigid ducting.
4) Baffle Boxes
A baffle box is a rectangular box that has several 90 degree angles that slow the air down and help reduce sound that travels from one room to the next through a duct system. They are great when your HVAC may be close to your soundproof room and you need a short duct system that is soundproof to get into your room. I used a baffle box system in my studio and it works great. Watch the video above to learn more about how to build a baffle box and get a feel for the design.
Conclusion
1) Create a large duct size to slow the air down
2) Don't make 90 degree turns in ducting close to your exit registers
3) Use round non-rigid ducting
4) Use a baffle box if your design would benefit from one
Do You Want To Learn More About Soundproofing?
Join Our FREE Soundproofing Workshop
Categories
All Categories 1/4 wavelength rule 101 2x4 a237 resilmount clip absorption absorption coefficient acoustic acoustic cauk acoustic caulk acoustic clips acoustic cloud acoustic cualk acoustic fields acoustic foam acoustic gobos acoustic holes acoustic panel lighting acoustic panels acoustic treatement acoustic treatment acoustics acousttic putty aes67 air space airflow airgap airlock airtight amroc angled walls aoip apartment audio gear protection audio interface ethernet audio networking audio over cat5 audio over cat6 audio over ethernet audio recording gear audio studio wiring avb avb audio backset backyard studio baffle box balanced power systems base basement basics bass bass traps bedroom recording studio beginner soundproofing blueprints bolt area bonello criterion boner bottom plate brick budget builder building soundproof windows cad calculator cantered walls carbon dioxide carpet glue cat5 cathedral ceilings caulking ceiling height cfm clean power for audio gear client work coincidence effect coincidence frequency communicating doors concrete concrete blocks concrete slab construction plans contractors control control room design cost creative studio lighting cubic feet per minute dante dante audio dante vs avb decibel levels decibel x decibels decibelx deciboard dehumidifier diaphragmatic diaphragmatic absorbers diffraction diffusion diy dolby atmos door door hardware double pane windows double wall double wall system double walls drums studio drywall ducted mini split ducting ductulator ductwork electrical emi and rfi interference solutions erv ethernet europe existing ceilings existing floors existing walls exterior wall extreme soundproofing fiberglass fiberglass insulation firestops flanking paths floating floor floating walls floor floor design flush mounting speakers flutter echo foam framing frequencies fresh air frost king weather stripping furring channel garage garage conversion gobo panels green building green glue ground loops prevention guitar amp iso cabinet hardwood floor harwood floor hat channel hat channel system hat channel wall system hat channels hat channels and loft floating floor heating and cooling helmholtz resonators helmholtz slot resonator hiring home recording home recording studio home recording studio build it like the pros home recording studio design home studio acoustics home studio gear home studio grounding home studio lighting home studio power solutions home studio vibe home theater how to build hrv humidity hush frame rafts hushframe rafts hvac i-b3 ib-1 clips ib-3 clips icf insulated concrete forms insulation isolated concrete slab isolated ground receptacles isolation clips isolation hangers knauf ecose insulation laminate glass latent cooling load led lights for studio lede listening position live room local codes log cabin louden low frequencies mason industries masonry mass mass air mass resonance mass loaded vinyl mass spring mass system master handbook of acoustics mastering mastering studio metal roof mini split minisplit mistakes mitsubishi mixing mlv modes moisture mold monitors mortise lockset mortised lockset mr cool nc levels nd isolator clip new zealand noise criteria noise criteria curve noise criterion curve non-environment room outsulation assembly owens corning 703 permits philip newell philips hue studio setup pipewrap plans plaster plywood podcast poly barriers polyurethane foam portfolio power conditioners for studios practice room prefrabricated shed pretty good house proaudiola producer professional studio design tips professional studio lighting putty pads q-sys q-sys by qsc qrd 13 quadratic residue diffuser quietrock r value rebond foam recording studio recording studio design recording studio door redco reflection free zone rehearsal room relative humidity revit rew rfz risc clips rockwool rod gervais roof room acoustics room modes room ratios room size room software room treatment safe n sound sand sand filled sbir scatter plates schroeder diffuser sensible cooling load sepmeyer shed silentfx drywall simple soundproofing single pane windows sketchup sliding door small rooms snakes soffit mounting speakers solid core doors sonarworks sonopan sooundproof soudproofing sound transmission sound transmission class soundbreak soundgrid soundgrid waves soundid reference soundproof soundproof beam soundproof beams soundproof bedroom soundproof booth soundproof budget soundproof ceiling soundproof ceilings soundproof curtains soundproof door soundproof door cost soundproof door seals soundproof doors soundproof drum room soundproof ducts soundproof expense soundproof floor soundproof floors soundproof glass soundproof materials soundproof method soundproof pipes soundproof shed soundproof sliding glass door soundproof studio soundproof studio tour soundproof underlayment soundproof wall soundproof walls soundproof window soundproof window insert soundproof windows soundproofing soundproofing budget soundproofing calculator soundproofing cons soundproofing cost soundproofing mistakes soundproofing on a budget soundproofing pros soundproofing stores soundproofing walls soundproofing101 sounproofing speaker calibration spl meter splayed walls spray foam staggered studs standing waves star grounding star grounding tips stc stc rating studio audio setup studio design studio design electrical studio design mistakes studio electrical setup studio lighting design studio lighting ideas studio lighting tips studio locations studio power solutions studio setup tips studio tour studio wiring best practices superheavy door surge protection for audio equipment surround sound sway bracing team tecsound tempered glass tl transformer power conditioning triple leaf efffect trudoor trunk rubber ups for home studios vapor barrier vapor open assemblies vapor variable membrane ventilation vocal booth vocal booth acoustics vocal studio voice over studio volkman voltage regulation for studios wall walls weight whisper room vocal booth wic wood furring xlr cables youtube youtube studio acoustics youtuber zero international 367aa zero international 770aa perimeter seal zero international seals