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ACOUSTICAL SEALANT CHOICES
AIR BYPASS LEAKS
AIR LEAK SEALING PROCEDURE
AIR TEST FOR MOLD: ACCURACY
ALLERGEN TESTS for buildings
ALLERGENS in BUILDINGS, RECOGNIZING
ANIMAL ALLERGENS / PET DANDER
ANIMAL ENTRY POINTS in buildings
APPLIANCE EFFICIENCY RATINGS
BLOWER DOORS & AIR INFILTRATION
BLOWER FAN CONTINUOUS OPERATION
BLOWER FAN OPERATION & TESTING
BUCKLED FOUNDATIONS due to INSULATION?
BUILDING NOISE DIAGNOSIS & CURE
CARPET PADDING ASBESTOS, MOLD, ODORS
CARPETING, SELECTION & INSTALLATION
CATHEDRAL CEILING VENTILATION
CHIMNEY INSPECTION DIAGNOSIS & REPAIR
COMBUSTION AIR for TIGHT buildings
DIRECTORY of MOLD / ENVIRONMENTAL EXPERTS
ENGINEERED WOOD Flooring
FIREPLACES & HEARTHS
FLOOR TYPES & DEFECTS
FRAMING DETAILS for BETTER INSULATION
FREEZE-PROOF A BUILDING
FROST HEAVES, FOUNDATION, SLAB
HEAT LOSS in BUILDINGS
HOUSE DOCTOR, how-to be
INDOOR AIR QUALITY IMPROVEMENT GUIDE
Insulation Air & Heat Leaks
INSULATION LOCATION - WHERE TO PUT IT
INSULATION R-Values & Properties
KITCHEN VENTILATION DESIGN
LOG HOME GUIDE
MOISTURE CONTROL in BUILDINGS
MOLD: A COMPLETE GUIDE TO MOLD
NOISE / SOUND DIAGNOSIS & CURE
ODORS & SMELLS DIAGNOSIS & CURE
PLASTER, LOOSE FALL HAZARDS
PLASTER TYPE IDENTIFICATION
PLUMBING DRAIN NOISE DIAGNOSIS
PLUMBING NOISE CHECKLIST
ROOF NOISE TRANSMISSION
ROOF VENTILATION SPECIFICATIONS
SLAB CRACK EVALUATION
SOUND CONTROL in buildings
Splits in Structural Wood Beams
STAIRS, RAILINGS, LANDINGS, RAMPS
SUMP PUMPS GUIDE
THERMAL EXPANSION of HOT WATER
THERMAL EXPANSION of MATERIALS
TRUSS UPLIFT, ROOF
VENTILATION in BUILDINGS
WALL FINISHES INTERIOR
WIND WASHING INSULATION At EAVES
WINDOWS & DOORS
WOOD FLOOR DAMAGE
This article explains methods and materials used to control heating, ventilation, and cooling duct noises and sound transmission in buildings: how to make a quiet home, office, or place of business using sound isolation for ceilings, floors, walls, plumbing, etc.
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Our page top photo shows a typical fiberglass lined HVAC duct interior. The gray debris stuck to the fiberglass is usually house dust, comprised chiefly of skin cells and fabric fiber. Sometimes more troublesome debris collects on interior HVAC duct insulation.
As stated in Best Practices Guide to Residential Construction: Use fiberglass ductboard or fiberglass duct liners to quiet the noises of fans and moving air. Avoid sharing a common duct between two rooms that need sound privacy.
Elaborating on some duct insulation considerations: HVAC experts advise us that conventional practice is to insulate the interior of metal ductwork in order to minimize transmission of HVAC equipment sounds throughout a building.
Some fiberglass duct liners are plastic coated and may be able to be cleaned using gentle procedures.
But most common is the use of un-faced fiberglass duct interior insulation, typically treated with a surface resin binder to help reduce movement of fiberglass particles into the air stream.
Our fiberglass lined duct insulation photo (left) shows clean new metal ductwork with a pink fiberglass mat sound and temperature insulation installed on the duct interior. Our page top photo shows that building dust and debris quickly adheres to fiberglass interior duct insulation.
However our work on indoor environmental and air quality topics suggests that from an indoor air quality maintenance view, we prefer to see insulation on the exterior of metal ducts.
That approach permits the ducts to be cleaned, and it reduces the chances of mold growth in the ductwork.
Mold in Fiberglass Insulation illustrates problem mold growth in fiberglass insulation including in duct systems.
Construction of HVAC ducts from foil-faced insulating board (photo above left) combines sound and temperature insulation with aluminum foil to product ductwork that is quiet and cleanable using gentle methods.
Other steps to reduce HVAC system duct noise in buildings include:
Our photo (left) shows a furnace mounted in a mobile home closet. Owners, in an attempt to reduce furnace noise in the adjacent living space, closed off the return air inlet by installing a solid door. Heating output was substantially reduced and heating costs increased by this bad practice.
-- Adapted with permission from Best Practices Guide to Residential Construction.
Continue reading about methods for sound control in buildings by using the links provided just below.
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