ASHRAE PMP Acoustical Testing

ASHRAE PMP Acoustical Testing

Setting benchmarks and measuring building performance is vital to designing successful “green” or high efficiency buildings. ASHRAE developed a set of Performance Measurement Protocols (PMP) to provide consistent test methods for the industry to measure energy, water, and indoor environmental quality performance of commercial buildings. The indoor environmental quality section includes acoustical measurements to assess things like background noise levels, speech privacy, reverberation, and sound isolation depending on the building usage. ASHRAE is working on evaluating and updating the PMP guidelines. As part of the process they commissioned a full series of measurements per the current PMP for a number of buildings. Wave Engineering performed acoustical testing for a LEED Platinum building, the Iowa Energy Center IUB/OCA building, in Des Moines, Iowa. The acoustical measurements in the PMP are divided into three groups: Basic, Intermediate, and Advanced. The Basic sound testing involves an occupant survey on acoustics and measurements of the background noise level in A-weighted decibels (dBA), which the client performed themselves. Wave Engineering was enlisted to conduct the Intermediate and Advanced measurements, which require more advanced instrumentation and expertise. The Intermediate level sound testing was performed in several rooms. These tests evaluate the most common sources of annoyance that affect work performance and interfere with communication: background noise and reverberation. Background noise from the HVAC system was measured and reported in octave band levels, dBA, dBC, Noise Criteria (NC), and Room Criteria (RC Mark II). Reverberation Time (T60) was measured in each room and reported in octave and 1/3-octave bands. The Advanced level testing was conducted primarily in a Hearing Room used by the Iowa Utilities Board....
PRODUCT HIGHLIGHT: Acoustic Plasters

PRODUCT HIGHLIGHT: Acoustic Plasters

We are featuring Acoustic Plasters as part of our continuing series of product highlights. Acoustic Plasters Acoustic plasters are troweled-on acoustic treatments that absorb sound, control reverberation, and reduce noise. They can be used in both exterior and interior applications.  Plaster can be applied in different colors a variety of textures (degrees of smoothness).  There is even an acoustically transparent shimmer effect that can sprayed directly onto the completed installation. This is a higher-end, more expensive treatment that must be applied by a certified installer. Photo by...
PRODUCT HIGHLIGHT: Acoustic Stretch Fabric Systems for Room Absorption

PRODUCT HIGHLIGHT: Acoustic Stretch Fabric Systems for Room Absorption

We like to stay on top of new products and innovations and thought it would be a good idea to feature some of them on our blog. Following is the first in our series of product highlights. Acoustic Stretch Systems Acoustic stretch systems are fabric or micro-perforated vinyl membranes stretched over plastic or metal frames with sound absorbing or sound blocking material behind. These treatments can cover larger areas with fewer seams than acoustic panels. Custom options can accommodate irregular shaped rooms, including curved walls and domes. Stretch systems can be an economical way to produce an updated look by covering existing treatments without removing them. Systems can be designed with the sound absorbing material only where needed. The fabric can conceal loudspeakers or hard reflective surfaces so that they are seamlessly integrated with the sound absorbing treatments. Acoustic stretch systems can accommodate a variety of fabrics to provide many different looks. Some vinyl membranes can be screen-printed and some can be backlit. Panels can be fabricated in geometric shapes, waves and other...
Featured Project: St. Catherine Greek Orthodox Church

Featured Project: St. Catherine Greek Orthodox Church

Wave Engineering recently had the pleasure of working with St. Catherine Greek Orthodox Church near Denver, CO to enhance the acoustics of their sanctuary. We used EASE acoustical modeling software to investigate changes to the surface finishes and shape of the room in order to maintain speech intelligibility and improve projection from the choir loft. As part of our analysis we also had the opportunity to research optimum acoustics for Byzantine chant, which is a key component of Greek Orthodox services. As you can see in the photos, the sanctuary is a beautiful space with multiple arches and domes, which also made it tricky to model in the software. Fortunately, Tim Politis with 1ine Studio provided a detailed SketchUp model of the room as a starting point. The EASE model allowed us to look at many different acoustical metrics in addition to the traditional reverberation time, and we were able to map the effect of different options across the seating area. This better informed the changes to the choir loft. We also used EASE to create auralizations of the different options, and we presented these on headphones to the church representatives so that they could hear and evaluate the changes. One of the elements we modeled was how much the reverberation would change with occupancy since the pews are not padded. Listen to the speech and chant clips below to hear the difference between the empty room and fully occupied, for example. Audio files: Speech – Unoccupied Speech – Fully Occupied Speech – Chant Unoccupied Speech – Chant Occupied For a complex room, 3D acoustical modeling provides a wealth...
Shooting Range Acoustic Consulting & Noise Control

Shooting Range Acoustic Consulting & Noise Control

Shooting Range Noise Sound transmission from gun ranges has become a growing concern as shooting sports increase in popularity, and firing ranges are built in close proximity to retail areas and residential districts. We work with developers, architects, engineers, and city planners to evaluate potential noise concerns from shooting facilities. Wave Engineering, Inc. evaluates new and existing ranges with computer modeling and on site sound measurements, and can assist with exterior noise, permitting, and compliance with state and local noise codes and ordinances. We can also recommend acoustic treatments to control noise and reverberation inside the range, retail, and classroom areas. For more information, please watch our video profile on gun range noise and acoustics, below… HVAC systems shown in this video are by Carey’s Small Arms Range Ventilation. To Get Help With Your Shooting Range Project Contact Us...
Are Your Video Conference Room Acoustics HD-Compatible? (Part Two)

Are Your Video Conference Room Acoustics HD-Compatible? (Part Two)

In a previous post, we discussed ways that the acoustics of a conference room can affect the audio quality of the video conferencing system. Here in Part 2 we will go over some general recommendations on designing the room to get the best sound from the system. Good Design Principles The three main pillars to good acoustical design for a video conference room are: 1. Low background noise 2. Low reverberation 3. Microphones located close to the talkers If you can provide those three items in all conference rooms, you can achieve the natural, immersive sound quality that your HD video conference system is capable of. Background noise The HVAC noise in the conference room should be less than 30 dBA or Noise Criteria (NC) 25. Most building HVAC systems will exceed this level unless care is taken to add lined duct, locate equipment away from the room, and use low air velocities. Many conference rooms have a glass wall looking outside or into a corridor or lobby area. Intruding noises like traffic or people talking outside the room can interfere with the conference too. Some conference areas are not even divided from the rest of the open office area, which is not a good idea for video conferencing. Reverberation An ideal conference room should have a reverberation time around 0.5 seconds. This is not possible in a room with a lot of hard surfaces like glass, drywall, concrete, or exposed metal deck. A reverberant room makes speech sound muddy and makes the background noise louder. Soft, sound absorbing materials are needed to control reverberation, and they should be...