Rooftop units are direct expansion refrigeration systems that heat and cool a building. They contain a condensing and air-handling unit section and have several noise transmission paths, including radiated noise, supply and return in-duct and break-out noise, structure-borne noise, and re-generated noise. However, traditional sound attenuators alone address only a few of these paths. We take a holistic approach when designing standard and acoustic-modeled solutions to ensure they can handle all the noise transmission paths while minimizing the impact on the unit’s efficiency, expertly manufacturing them according to your precise specification requirements.
Scroll down to explore our noise and vibration solutions for rooftop unit systems.
STA
2-5dB(A)
Standard
This is a treatment of the compressor circuits for chillers with Screw Compressors. HUSH COVERS are used for the compressor housing, suction and discharge piping and oil separator vessels.
Sample Installation Images
Standard Highlights
- Source Control using HUSH COVER™ removable sound blankets
- Model HC-500S-1 blanket construction
- “D” ring fastening bands with Velcro flaps
- The SL System treats only the scroll compressor to achieve a 2 to 3 dB(A) typical noise reduction
- The SC System treats chiller circuit parts, all compressors, suction lines, discharge pipes and oil separators to achieve a higher 4 to 5 dB(A) typical noise reduction
WHI
Whisper
Sample Installation Images
Whisper Highlights
HPC-DS-49-E
- Plenum Vibration Curb with acoustical panel floor and offset SA and RA openings
- Controls structure-borne vibration, radiated noise and fan noise
- HUSH DUCT™ Silencers at supply and return curb openings (below deck)
- Ductwork connections to bottom of plenums can be field cut upon request
DEC
Deck
MODEL DS-30
MODEL DS-38
The model DS-38 Deck™ System is a multi-layer configuration which is an excellent alternative to traditional gypsum board treatments for equipment curbs. The DS-38 System outperforms traditional treatments and provides lower octave band transmission loss performance.
MODEL DS-40
MODEL DS-41
The model DS-41 Deck™ System is a multi-layer composite configuration that achieves excellent performance when used to attenuate RTU in-curb radiated noise. This cost-effective assembly is rated at STC-41 and out performs gypsum board treatments by up to 5 STC points.
MODEL DS-45
MODEL DS-53
The HUSHCORE® model DS-53 Deck™ System uses the same composite acoustic panels as our DS-52 System and is an equivalent offering. The DS-53 provides a high level of transmission loss for equipment curbs installed overtop noise sensitive spaces. This assembly provides for a quick and easy installation without sacrificing acoustic performance. BRD offers a variety of DECK system models depending on your noise sensitive project.
Sample Installation Images
Deck Highlights
LIN
Linear
The HUSHCORE® Linear™ System is a non-fibrous, non-fiberglass, fiber-free, fire-rated open cell acoustic foam duct liner. Consider this product when designing projects for owners who do not want exposed respirable fibers in the HVAC air stream.
Sample Installation Images
Linear Highlights
- Reduces in duct fan noise transmitted to occupied spaces via the ductwork system
- Fiber-free Non-Fiberglass model HLM-100-N open cell acoustic foam duct liner
- Noise Reduction Coefficient acoustic rating of NRC .80 for 1” thick
- Air Erosion Evaluation complies with requirements of UL 181, section 16
- Resistant to microbial growth
- Flammability rating of Class 1 per ASTM E84 and NFPA 255
- Installs with traditional adhesives and methodologies
ULT
Ultra
ULTRA is a plenum-style acoustical curb system and multi-path total noise control solution for rooftop curb-mounted HVAC equipment. The in-curb design features HUSH DUCT silencers and a solid bottom HUSH GUARD modular acoustical panel floor to facilitate side-by-side supply (SA) and return (RA) alignment. In addition, ULTRA includes an integrated, sealed, and pre-assembled vibration isolated curb with internal in-curb deck treatment. Snubbers help resist wind and seismic forces, and completely isolated top and bottom steel structural frames feature a continuous flexible weather seal.
Sample Installation Images
Ultra Highlights
- Integrated In-Curb Design with recessed horizontal HUSH DUCT™ silencers
- Multi-Path Total Solution
- Solid bottom HUSH GUARD™ HG-210 modular acoustical panel floor
- Ductwork connections offset in curb bottom panel from unit openings
- Ductwork connections can be field cut upon request
- Facilitates side by side SA and RA alignment
BAR
Barricade
Duct radiated or breakout noise can be effectively attenuated using the HUSHCORE® Barricade™ System. For downflow rooftop unit installations, treatment of the first 15’ to 20’ of SA and RA under the unit is most critical. Model LVQ-210-LAG material is an externally applied composite sound insulation.
Sample Installation Images
Barricade Highlights
- Reduces supply and return duct breakout and
Supply drop with BARRICADE™ System external acoustic lagging radiated noise - Composite exterior acoustic insulation using quilted fiberglass and loaded vinyl flexible barriers
- HUSH WRAP™ dual density construction model LVQ-210-LAG
- Tested for Insertion Loss per ASTM E-1222 “Standard Test Method for Laboratory Measurement of the Insertion Loss of Pipe Lagging Systems”
- Installs with banding, adhesives and/or mechanical insulation clip fasteners
- Seams and overlaps sealed with matching FSK tape.
SUP
12-15dB(A)
Supreme
Supreme™ System perimeter sound barrier walls are enclosures constructed of HUSH GUARD™ panels with a wind load rated, PE stamped structural steel framework. Optimal system performance is for barriers that are 2-3’ taller than the equipment. Acoustical air intakes and discharge stacks may also be needed to manage the unit operating efficiency impact.
The Supreme™ “PVC” System is a perimeter sound barrier solution constructed using all weather, lightweight corrosion resistant HUSH GUARD™ PVC panels. This product design is similar to the metal version but may be preferred where there are weight limitations or where environmental conditions such as coastal sites (near salt water) may dictate.
Sample Installation Images
Supreme Highlights
- Path Control Treatment
- HUSH GUARD™ modular acoustical barrier wall
- 12 to 15 dB(A) typical reduction
- HUSH GUARD™ panel construction
- Panels can be installed without a crane
- Superior weather resistant non- corrosion construction
- Performance is based on variations such as enclosure/wall height, distance to unit, and panel construction.
SUM
10-12dB(A)
SUMMIT
The Summit System for rooftop units is a source-applied treatment of the intakes and discharge fans using Hush Guard panels and Hush Duct Silencers. Hush Cover removable acoustic jackets address vibration and breakout noise concerns from the RTU’s circuit components. These high-performance solutions do not require roof penetration for costly and extensive structural steel framing supports.
Sample Installation Images
SUMMIT Highlights
- Three-part source-applied treatments include Hush Guard panels, Hush Duct Silencers, and Hush Cover removable acoustic jackets
- Specialized unit mounting and attachment allow the source-applied treatment to be supported by a roof curb already needed to support the RTU
- The curb manufacturer must accommodate the extra weight so as not to void or affect the equipment warranty, but curb design modifications beyond a spring upgrade for vibration curbs are often minimal. Our system integration is coordinated with the equipment/OEM as to not void unit warranty when mounted to the unit direct.
- Absence of roof penetration helps prevent costly and extensive structural steel framing supports
- For RTU's up on dunnage, roof steel or platforms we can also provide Hush Guard panels to provide noise treatment below the units.
UNI
4-6+dB(A)
Unitary
The Unitary™ “TM” System is a top mounted, unit supported plenum style acoustically insulated stack constructed using HUSH GUARD™ sound panels. Condenser fan outlet noise can be reduced by 4 to 6 dB(A) with this treatment.
The Unitary™ “IS” System is an independently supported, wind load rated plenum style acoustically insulated stack constructed using HUSH GUARD™ sound panels. Condenser fan outlet noise can be reduced by 3 to 5 dB(A) with this treatment.
Unitary™ SM-SB Systems are available in both top mounted and independently supported constructions. This variation of the Unitary™ System design adds silencer modules to fit inside the HUSH GUARD™ plenum stack for increased performance and where noise sensitive receiver locations are elevated above the equipment. Baffle thickness, spacing and depth determine overall performance.
Sample Installation Images
Unitary Highlights
IS
- Source Control using HUSH GUARD™ modular acoustical panels
- Attenuates condenser fan exhaust
- 4 to 6 dB(A) typical reduction
- HGU panel construction
- Outperforms Low Noise Fans
- Minimal pressure loss impact
- Wind Load rated
TM
- Source Control using HUSH GUARD™ modular acoustical panels
- Attenuates condenser fan exhaust
- 4 to 6 dB(A) typical reduction
- HGU panel construction
- Outperforms Low Noise Fans
- Minimal pressure loss impact
- Designed to be bolted to and supported by the chiller
SM-SB
- Source Control using HUSH GUARD™ modular acoustical panels
- Splitter inserts for increased attenuation of condenser fan noise
- Attenuation can vary from 6 to 12 dB(A) depending on splitter configuration
- HUSH GUARD™ type HGU panel construction
- Outperforms Low Noise Fans
- Minimal pressure loss impact
- Available in both “IS” Independently Supported/Grade mounted and “TM” Top Mounted/Unit Supported configurations
PLUS
plus
PLUS Type P, and Type V acoustical curb systems isolate structure-borne noise and vibration and reduce in-curb radiated noise from rooftop curb-mounted equipment. The construction of these fully adjustable and assembled systems features built-in springs with limit stops to snub out wind resistance. They can also serve as a blocking device during installation. In addition to the above - with completely isolated top and bottom steel structural frame - only our PLUS-E & PLUS-V systems can provide fan sound attenuation for supply and return duct-borne paths as well.
Sample Installation Images
plus Highlights
HIC-DS-41, HIC-DS-53
- Isolates structure-borne noise and vibrattion
- Reduces in-curb radiated noise
- Base™ System Hush Cure™ Vibrations Curb with Deck™ System in-curb composite acoustical treatment
HIC-DS-38, HIC-DS-538-E. HIC-DS-41-E, HIC-DS-53-E
- Isolates structure-borne noise and vibration
- Reduces in-curb radiated noise
- Minimizes radiated, in-duct, and breakout noise
HPC-DS-49-P
- Controls structure-borne vibration, radiated noise and fan noise
- Plenum Vibration Curb with acoustical panel floor and offset SA and RA openings
- Ductwork connections to bottom of plenums can be field cut upon request
- Facilitates side by side SA and RA alignment
HIC-DS-41-V, HIC-DS-53-V
- Controls structure-borne vibration, radiated noise and fan noise
- Base™ System HUSH CURB™ with Deck™ System in-curb acoustical treatment and HUSH DUCT™ silencers
- Integrated in-curb HUSH DUCT™ vertical duct silencers and flex connectors
- Ductwork connections to downflow silencers
LOU
5-7dB(A)
Louver
The Louver™ System uses high performance type HUSH DUCT silencers up to 36” deep for direct bolting to the chiller cabinet/frame. Typical reductions of the condenser inlet noise are 3 to 5 dB(A). Greater reductions can be achieved when combined with other source treatments.
Sample Installation Images
Louver Highlights
- Source Control using HUSH DUCT silencers up to 36” deep
- Direct mounting of louvers to upper side intake coil area and/or lower open framing
- Galvanized steel construction
- Range is 350 FPM (ideal) to 600 FPM maximum
- Additional Hush Guard (hard) & Hush Flex (soft) panel options for blanking off openings and Chiller ends to treat breakout noise.