How Innovation in Testing and Training is Driving the HVAC Industry Forward

The virtual tour of this state-of-the-art laboratory and interactive learning experience is a must-see.

Technical innovations, such as virtual and augmented reality along with predictive analytics, continue to advance the engineering, architectural and construction industries while simultaneously helping companies improve their quality, safety, efficiency and costs.

At Titus, we have a history of innovation and a goal to continue to advance the science of air distribution. By embracing new technologies and incorporating them into our existing sales, marketing and training, it makes us more capable to interact with these industries and the next generation of industry professionals.

In addition to our product innovations, we invest in a state-of-the-art lab and classroom that we call the Comfort Zone. Spread over 39,500 square feet, our laboratory provides an extensive array of testing and mock-up services that allow guests to truly immerse themselves in all aspects of HVAC design. And you won’t find a traditional training room here; instead we offer an interactive learning experience.

Get behind-the-scenes highlights and take a virtual tour

The facility includes underfloor testing, throw rooms, a critical environment lab, innovation towers, a reverb room, a chilled beam testing chamber and in-situ rooms. I’ll walk you through a few special features and then share a link to a virtual tour of the entire facility.

Underfloor testing

The Underfloor Air Distribution (UFAD) room is a multi-purpose space designed to demonstrate underfloor products, cold wall situations, and serve as an auxiliary throw room for ceiling diffusers. The UFAD room can showcase air patterns created by various models of ceiling diffusers and be used as a mock-up facility to show unique solutions for tricky air distribution problems. During smoke test demonstrations, thermal imaging dramatically shows the difference in the temperature. Underfloor diffusers are floor mounted to simulate actual site installation and test air is precisely delivered to the diffusers at a flow rate of up to 5,000 cfm. Any site requirements for equipment and furnishings can be mocked up to resemble real-world installations for an accurate determination of airflow patterns and temperature mapping. The effect of sills and soffits on air diffusion against an external wall can also be studied.

Throw room

This 80'L x 28'W x 9'H room tests products with increased accuracy, including slot diffusers with long throw, large size displacement ventilation units and chilled beam products. A modular hydronic system enables the testing of chilled beam and water sourced products while units are operating at cooling and/or heating mode. A 20' x 40' radiant heater is installed under the floor for better load control of the room during various performance testing, including isothermal throw tests and isovel air pattern mapping in accordance with ASHRAE Standard 70.

Critical environment lab

In this specialized room, we model laminar flows in a cleanroom or laboratory setting with a cleansing air wash or an isolating air curtain. Physical site conditions are mocked up in the room to determine the effect of equipment placement on airflow patterns, and smoke can be easily introduced into the air stream by remote control. Test air is precisely delivered to a diffuser by a computer-controlled delivery system at a flow of up to 5,000 cfm. Isothermal heated or chilled air can be supplied to any diffuser inside the critical environment room for a 30 degree F temperature differential.

Innovation towers

Within three towers, visitors can interact virtually with Titus products on a tabletop display and experience them firsthand. Product displays include the Spectrum Diffuser, Underfloor, VAV, Energy Solution products, Chilled Beams, Radiant Ceiling Panels and Terminal Units.

Reverb room

Our reverberation room allows pure tone sound testing qualification per AHRI-220-2007. It is acoustically isolated from outside noise and vibration with room-inside-a-room construction and an isolation base. Advanced sound measurement equipment offers precise and highly repeatable testing. With a custom-made modular hydronic system, products with water cooling/heating coils can be tested for sound performance while units are operating in cooling or heating mode.

Chilled beam testing chamber

Our chilled beam testing chamber is one of two test chambers located in the United States. It is used to conduct capacity testing in accordance with ASHRAE Standard 200, as well as research and development testing for our chilled beam product line. It features room-within-a-room construction with a conditioned buffer space that prevents heat transfer into or out of the inner test chamber. Precise instrumentation measures the operation conditions and delivered capacity of the unit under test. During testing, the room temperature is maintained within 1 degree F through the use of load dummies. The energy used to maintain space temperature is measured as a validation of the measured capacity. The chamber also features automated control and data acquisition software which enables incredibly precise test results at an increased pace of testing.

In-situ rooms

Two different sized in-situ rooms are built with a 3' plenum space allocated above the ceiling for terminal unit installations. With commercial carpeting, drywall, mineral board ceiling tiles, light fixtures and t-bar grid ceiling construction, these rooms mimic typical office spaces and are built per Cerami and Hines in-situ room specifications. Advanced sound meters make high-precision noise measurements and are frequently used for radiant and total sound mock-up tests requested by building owners and engineers.

See it for yourself

Ready to start your virtual tour? Let me know which part looks most intriguing to you.

For an innovative solution to meet your unique needs, visit titus-hvac.com.

Looking to the future,

Jenny Abney Sivie, LEED AP BD+C - Director of Advanced Business Development, Titus HVAC

This article as written can be found on LinkedIn's website https://www.linkedin.com/. For information on this topic, please contact Jenny Sivie at jsivie@titus-hvac.com or Titus Communications at communications@titus-hvac.com.

6 Tips on Designing for Sound with Terminal Units

How to implement effective acoustic design with terminal units

As anyone wearing headphones at the office to keep coworkers from bothering them can tell you, noise is an issue in public spaces. While the primary focus of HVAC systems is temperature and humidity control, experienced designers know that controlling sound is vital to a comfortable and productive environment.

Total peace and quiet may sound relaxing, but actually isn’t ideal. Acoustic privacy is a state where someone at their desk can hear nearby conversations, but not enough to be distracted by them. Good acoustical design is not about trying to eliminate sound, but rather manage it appropriately. Too quiet and you destroy acoustic privacy. Too loud and you interfere with speech or even cause hearing damage. You also don’t want any annoying rumbles, hisses, identifiable machinery sounds, or undue modulation of the system cycling off and on over time. 

Good design practice requires mechanical system designers to establish the acceptable noise for an occupied space and then determine the selection criteria for all system components. AHRI Standard 885, Procedure for Estimating Occupied Space Sound Levels in the Application of Air Terminal and Air Outlets, provides a consistent method and the most current application factors. This article won’t cover the calculations involved, but rather focuses on underlying factors and actionable recommendations. 

The key approach to noise control breaks each issue into three overall components: the source that creates the noise, the paths that transmit the noise, and the receiver who hears the noise. Air terminals are often a primary source of sound in a mechanical system. The path for sound emanating from an air terminal is either through the plenum, down the duct into the conditioned space where it reaches the occupant, or some combination of both. 

In any application, both radiated and discharge sound needs to be considered. Radiated sound escapes through the terminal casing and/or induction port and travels through the plenum and ceiling to enter the occupied space. Discharge sound travels out the terminal through the ductwork and air outlet. Radiated sound is the primary issue when using fan-powered terminals, while discharge sound is common with non-fan terminals. Unlined ductwork can result in higher discharge sound levels for all terminal types.

Once the radiated and discharge sound paths are determined, the resulting room sound level can be evaluated. Several factors outside the mechanical system play a part, including the dimensions of the room, carpet and furniture, just to name a few. An accurate analysis is a complex process, and as a reminder, AHRI Standard 885 provides a consistent method for accomplishing it. 
Engineers can minimize the sound contribution of air terminals to an occupied space with the following good design practices: 

• Whenever possible, terminals should be located away from occupied areas and placed over areas less sensitive to noise such as corridors or storage areas.
• Use lined ductwork or attenuators downstream of air terminals to help attenuate higher frequency discharge sound. Used in moderation, flexible duct is also an excellent attenuation element. However, remember to keep flexible duct bends as gentle as possible.
• Sharp edges and transitions in the duct design should be minimized to reduce turbulent airflow and the resulting sound contribution.
• Rather than using mechanical devices to restrict airflow, use fan speed controllers to reduce fan rpm. This form of motor control also often has the added benefit of being more energy efficient, especially when applied to ECMs.
• Separate the air terminal and return air grille as far as possible, in order to allow duct attenuation to reduce discharge sound levels.
• Design systems to operate at low supply air static pressure. Not only will this reduce the generated sound level, it also provides more energy efficient operation and allows the central fan to be downsized.

While it is crucial for designers to understand acoustical ratings in order to write good specifications, the careful selection and proper installation of every element of the entire system are required to ensure an optimal environment. Using the best products for the job will save you time, money and headaches in the long run. 

For additional guidance and innovative solutions to meet your unique needs, find your local Titus representative at titus-hvac.com.

Always here to help, Randy

Randy Zimmerman is a Chief Engineer at Titus and is an ASHRAE DL and LEED Green Associate with more than 30 years of experience in HVAC product development and applications. He serves on numerous ASHRAE technical committees and also represents Titus in various AHRI product section committees. 

This article as written can be found on LinkedIn's website https://www.linkedin.com/. For information on this topic, please contact Randy Zimmerman at rzimmerman@titus-hvac.com or Titus Communications at communications@titus-hvac.com.

Helios Installation and Operation Video

3 Trends Driving HVAC Innovation and How to Take Advantage

Three trends continually drive innovation in the HVAC industry. Solar, green building and the unique needs of critical environments are making heating and cooling systems more cost-effective for engineers and architects, more efficient for building owners, and ultimately more enjoyable for occupants. Even better news; cutting-edge technology in our field has never been so accessible. 

Solar Power

Solar power has moved from promising to a proven solution and it’s popularity shows no signs of slowing down. Indeed, as adoption continues to increase, the cost of components and installation continues to improve. The advantages are clear. Not only does renewable energy pay benefits for years to come, but solar is also enabling innovative product designs. Helios, for example, is a new digital diffuser from Titus that is powered by ambient light. It requires zero building power and no additional ductwork making it easy to install. Every Helios diffuser has a digital, wireless thermostat, so instead of having multiple offices lumped together in the same zone, each one can be controlled separately by the occupant of each space. That means no more back-and-forth over the ideal temperature, so the Helios solar-powered diffuser delivers even greater energy efficiency.

Green Building

Green building isn’t just a feel-good choice; it also makes good business sense as client demand continues to increase. The trick is finding cost-effective options that meet the rigors of LEED certification. A solution that delivers on both counts are chilled beams. This convection HVAC system utilizes hydronic coils and induced air to reduce energy consumption associated with the removal of sensible thermal loads. Since water is more efficient for space cooling and heating than air, chilled beams use considerably less overall energy than the other traditional options available, such as VAV and fan coil units. The hydronic capabilities of chilled beams complement the conditioning of the primary air ventilation system to optimize savings in ceiling cavity space, maintenance, and energy consumption. If you want maximum flexibility, the CBAL-24 chilled beam is available in lengths from two to ten feet.

Critical Environments

Since the safety of people and the protection of critical assets are at risk, critical environments, such as operating theaters, laboratories, and clean rooms, must meet specific requirements that are more demanding than typical commercial spaces. Air filtration, humidity, temperature, and pressurization must all be tightly controlled. The Atlas Operating Room Ceiling System (AORCS) is a field-assembled, gasketed, heavy duty ceiling grid designed to make it quicker and easier to build these highly regulated spaces. Every AORCS is custom engineered to meet all codes and guidelines while delivering lower operational costs, less maintenance needs, and increased energy savings. 

All three of these trends are having a positive effect on both the performance and cost of HVAC systems. With a history of being first to market with the most innovative approaches to air distribution, Titus remains focused on providing technologically advanced products that create the highest degree of comfort and energy efficiency.

For an innovative solution to meet your unique needs, visit titus-hvac.com,

Jenny Abney Sivie, LEED AP BD+C - Director of Advanced Business Development, Titus HVAC

This article as written can be found on LinkedIn's website https://www.linkedin.com/. For information on this topic, please contact Jenny Sivie at jsivie@titus-hvac.com or Titus Communications at communications@titus-hvac.com.

Do you know what Buy American means?

There’s some confusion when it comes to the question of Buy American and about requirements for compliance certification. This shouldn’t come as a surprise to anyone, as the laws and regulations that come into play really do appear to have done their best to turn a relatively simple concept into a convoluted quagmire of law titles, numbers and exceptions. So when a specifying engineer or rep puts in a request for compliance certification, do they really know what they’re asking for, or why?

Titus has plants in the U.S. and Mexico and is able to comply with Buy American requirements with all of our products, but it’s important to note that some electrical components are not made by any manufacturer in the U.S. these days. 

Let’s take a closer look at what it all really means.

Way back in 1933, in the darkest days of the Great Depression, President Herbert Hoover signed into law a bill called the Buy American Act. This law required that the federal government buy only American-made products wherever possible. Of course, even way back then, before the onset of the global economy that we have today, it was necessary to define what “American-made” actually meant. The definition, according to the 1933 law, was that at least 50% of the product or its materials must originate in the U.S. The law also allowed for products in countries with trade agreements with the U.S., if the federal project’s contract value was greater than $7,443,000. So under the Buy American Act, a federal government project exceeding that amount can purchase products made in America or any country with a trade agreement with the U.S. This would include NAFTA.

Still with me? Stick around, it gets even better. 

In 2009, President Obama signed into law the American Recovery and Reinvestment Act. This law included a Buy American clause — quite separate from the 1933 law — which stipulated that no economic stimulus grants should be made unless ALL the manufactured goods on the project are made in the U.S., with just a very few exceptions relating to cost and availability. However, this clause relates only to purchases made using funds provided by this law’s stimulus grants. As these grants are quickly becoming a thing of the past, this type of Buy American compliance is also becoming less and less relevant. 

More and more complicated

When engineers ask for Buy American Compliance Certification, the question is, which type of Buy American do they mean? Do they mean according to the 1933 Buy American law, or the 2009 Buy American clause in the American Recovery and Reinvestment Act? For the sake of clarity, we can talk about the 1933 Buy American Act by the acronym BAA, and the 2009 Buy American clause in the American Recovery and Reinvestment Act as ARRA. 

It should come as a surprise to nobody that the American economy has changed since the 1930s. Eighty-five years ago, manufacturing was still very much a domestic business. Today, companies buy components of all kinds from all corners of the world for assembly, together with components produced here at home. A company like Titus manufactures complex machinery that includes everything from steel casings, control boards, switches, sensors, tubing , motors and blowers. Occasionally, there are components — for example, some special electronic parts — that simply aren’t available from domestic manufacturers. In these cases, neither the Buy American definitions in the BAA or ARRA can apply unless the component meets the exceptions. 

Treaties and trade agreements under discussion 

There’s plenty of discussion these days about trade treaties, and specifically about NAFTA. The current administration has talked about renegotiating aspects of the treaty to secure terms more favorable to the U.S. Until this renegotiation takes place, NAFTA is still in place. There’s little support in the industrial community for any unilateral withdrawal from NAFTA. In fact, the U.S. Chamber of Commerce has gone on record as being firmly against any disturbance of the current treaty. We can be cautiously optimistic that under any circumstance, the trade agreement will either remain in place or conceivably be improved upon from the U.S. point of view.

Compliance and more compliance

The point of this article is simply to help those purchasing commercial HVAC equipment — and even those reps selling that equipment — better understand what compliance means, and which laws they’re trying to comply with. At Titus, we can provide Buy American Certificates of Compliance regarding both ARRA (2009) and BAA (1933) where requested. In other words, Titus is a proud American manufacturer of commercial HVAC systems. So when you’re ready to Reinvent Your Comfort Zone, you need look no further than to your friendly, local Titus manufacturing plant. For more information, you can check with your local Titus representative.

Until next time,

Jenny Abney Sivie, LEED AP BD+C - Director of Advanced Business Development, Titus HVAC

This article as written can be found on LinkedIn's website https://www.linkedin.com/. For information on this topic, please contact Jenny Sivie at jsivie@titus-hvac.com or Titus Communications at communications@titus-hvac.com.

Is business looking up for engineers and architects?

More and more, architects and design engineers are looking to the ceiling for inspiration. Not staring upwards because they don’t know what to do next, but because they do. Today, they know that chilled beams can be an inspiring solution to providing excellent and economical comfort in the buildings they’re designing or renovating. 

For many years, cooling and heating in public spaces was provided by heating coils or AC units and vents, or by water-filled radiators. We’ve all seen — and probably heard — old, clunky systems with fans that sounded like aircraft taking off, or old water radiators that made strange gurgling or knocking noises. No more. Today, we have efficient, economical and above all comfortable climate control in our public spaces. Look up and find the chilled beam. 

The popularity of chilled beam heating and cooling systems really began in Australia and in Europe, based on their efficiency and efficacy. For one reason or another, we’ve been a little slower to adopt the system here in North America, even though it was first introduced almost a half century ago. Today, however, chilled beams are hot, even if that’s a strange way of putting it. 

Active or passive?

There are two main types of chilled beam — passive and active — and Titus makes both of these. Describing the difference in detail between active and passive can be complicated, but the short version is that it all depends on the way the systems treat airflow and the introduction and control of outside, fresh air. 

In active systems, fresh air is continuously supplied to the chilled beam itself for ventilation. The supply of ventilation air creates induction, which pulls room air over water coils in the chilled beam, cooling the air and providing comfort to the room. Passive chilled beams deliver comfort using natural convection and use a separate fresh air system for ventilation. Downward flows of cool air mix with ambient air. The warmed air in the room rises and is then cooled by the coil in the beam, and the cycle begins again. Fresh air is introduced using a separate air handling unit (AHU). 

There are also integrated chilled beam systems — such as the new Titus product, VENTUS LUX — which combine the advantages of an active chilled beam system with the benefits of LED lighting to deliver heating and cooling together with lighting in a single, economical package. The exciting new VENTUS LUX system is a breakthrough in chilled beam technology and is beginning to enjoy a great deal of interest from architects and engineers busy with new construction, particularly from those working with retrofit projects. 

Looking sideways, too

In addition to ceiling-mounted systems, we produce displacement chilled beam units that combine the best of chilled beam technology and displacement ventilation. These units are mounted at the floor level around building or room perimeters, and are particularly suited for zones where the heating load is heavy. Placement examples are high-density rooms or areas in schools or in healthcare facilities, delivering the highest levels of clean, comfortable air where the demand is greatest.

Comfort is key

As you may know, if there’s one thing that we, at Titus, like to obsess about, it’s occupant comfort. That’s what all our systems are designed to deliver. Of course, we also think about economy, efficiency, sustainability, and practicality. At the end of the day, though, our systems have to deliver comfort. If they don’t, then we’ve failed in our mission. Luckily, the good news is that we’ve succeeded in our declared goals for the past 70-plus years, and we’re still going from strength to strength. 

So with chilled beam systems, the options available to architects and engineers — and owners, too — are definitely looking up. It may have taken us a little time here in North America to get up to speed, compared with counterparts down under and across the pond, but we’re making up for lost time. Chilled beam systems are now delivering comfort to more and more public spaces in our neck of the woods. Plus, when it comes to developing the current and coming generation of chilled beam systems, Titus is right there at the forefront. 

For more information about our full range of chilled beam products, talk to your Titus representative, or explore our website. You may also enjoy our podcast — Titus Timeout — where you’ll find brief episodes that cover many things HVAC, including chilled beam.

Until next time,

Jenny Abney Sivie, LEED AP BD+C - Director of Advanced Business Development, Titus HVAC

This article as written can be found on LinkedIn's website https://www.linkedin.com/. For information on this topic, please contact Jenny Sivie at jsivie@titus-hvac.com or Titus Communications at communications@titus-hvac.com.

Top Five Benefits of HVAC and Lighting Control Integration

System integration results in increased energy efficiency, lower costs, and overall enhanced design

 Learning objectives:

• Explore chilled beam and lighting control integration
• Understand the benefits of integrating HVAC and lighting controls

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Too often, building systems are designed and constructed as disparate fragments that need to work together. Essential services, such as lighting, heating/cooling, and building controls, compete for limited space, resulting in congested ceilings. In recent years, some of these systems have broken the status quo and joined forces as one integrated component.

One such integration is chilled beams and lighting. The two have quite a bit in common: They are impacted by the number of occupants and daylight present in the room, they keep occupants comfortable and productive, and they try to do this using as little energy as possible. Here are the top five reasons why this concept of integrating chilled beams and lighting systems can be a good choice for some buildings.

1. Higher energy efficiency

Chilled beams have inherent energy-efficient capabilities that are also present when integrated with lighting. Traditional HVAC systems use air, whereas chilled beams take advantage of water’s increased volumetric heat capacity to regulate a space’s temperature. It’s because of this that they can typically reduce HVAC energy consumption by up to 50% to 60% as compared with traditional systems.

But chilled beam systems, like other HVAC systems, must be designed properly to achieve full energy-savings potential. The key is to minimize the primary airflow rate to transfer as much of the space’s sensible cooling load onto the more efficient waterside of the system.

It is also important to maximize the induction rate. Here’s how it works: Active chilled beams have two distinct cooling components—the primary air and the water coil. Air induced from the space is cooled by the chilled-water coil and is affected by the inlet pressure and nozzle size (the smaller the nozzle, the greater the induction rate). Low-pressure zones are created around the jets of primary air as they exit the nozzles. The low-pressure zones induce room air over the chilled-water coil, which then cools the air and provides sensible cooling. A higher induction ratio shifts more of the cooling load onto the water coil, which can lead to greater energy savings. (See Figures 1a and 1b).

2. Lower total lifecycle costs
   
   

Beyond lower energy costs for building owners, there are also reduced installation costs associated with integrated systems. When both a space’s lighting and HVAC systems are in one component, there’s decreased complication during install. A common perceived hurdle to adapting this kind of integrated system is who does the install, a mechanical contractor, an electrician, or the sheet metal contractor? The answer is that the mechanical contractor usually installs the beams first and the electrical contractor then makes the final electrical connections. 

Integrated lighting and chilled-beam systems also have the potential to reduce building height. As chilled-beam systems are designed with around 70% less air than traditional all-air systems, the ductwork is considerably smaller, which often results in a slab-to-slab heat reduction of 12 in., leading to more flexibility in building construction.

Even beyond the initial installation, chilled beams continue to produce opportunities for savings. Maintenance costs decrease because chilled beams don’t have blowers, motors, filters, or condensate pumps. Instead, they rely on dry coils to operate, which only require cleaning once every 2 to 10 years, resulting in lower lifecycle costs.

3. Better indoor environment for occupants

A comfortable indoor environment should be a high priority when choosing and designing a building’s HVAC system. Traditional systems can have unpredictable ventilation performance (where some areas of the building are overventilated and others are underventilated), difficulty mixing during part-load conditions, and imprecise humidity control.

Chilled beams are often paired with dedicated outdoor-air systems (DOAS), which ensure all zones of the building receive correct ventilation and dehumidification at all times. Chilled beams allow the sensible cooling (and heating) to be decoupled from the ventilation and dehumidification requirements of the building. Precise control of these three elements reduces energy consumption, as over-ventilation and dehumidification is far less likely. They also typically operate at a constant volume, which allows for better mixing and an even temperature across the room.

4. More enhanced aesthetics 

HVAC is traditionally thought of, from a design standpoint, as a system that must be incorporated out of necessity and not because of what it adds visually. The integration of lighting and chilled beam reduces the visual mass of the systems in the ceiling plane, allowing for a less cluttered look without sacrificing a quality HVAC system. The product itself can have a cleaner look, as well, with sleek designs that are seamlessly incorporated into ceiling plans. Some systems are developed with input from architects on what design aspects are appealing to building owners.

5. Future potential for integration and innovation

One of the most exciting parts of this system integration is that it’s only the start of system integration. Future possibilities will expand beyond just lighting and HVAC to encompass a range of possibilities, from building safety requirements like fire suppression, security systems, and carbon monoxide detectors to other building benefits like occupancy sensors and sound bars for intercom systems or other sound-projection needs. Not only will the products integrate, but the associated controls will as well.

For example, occupancy sensors can monitor when and how many people are in a space to adjust the load setting accordingly or additional sensors can monitor the strength of sunlight and lower lights as needed to increase energy efficiency. Eventually, these will also integrate into building control systems and the Internet of Things (IoT) to further allow different systems to communicate and work together.

Future innovations like these can lead to additional efficiencies in installation costs because these innovations will prioritize a building’s design and function as a whole rather than approaching each system individually.

Considering humans spend 90% of their time indoors, it makes sense that our building needs have evolved and our spaces have become smarter, thanks in part to IoT. Our building systems need to keep pace, too. Consider a holistic building systems approach that integrates multiple components to optimize performance and create the best possible indoor environment.

This article as written can be found on Consulting-Specifying Engineers website https://www.csemag.com/. For information on this topic, please contact Nick Searle at nick.searle@titus-hvac.com or Titus Communications at communications@titus-hvac.com.

Round vs. Flat Oval Ductwork

Diffuser Sound - Part I / Making the Best Selection for Your Occupant Space

The acoustical environment created by an HVAC system may or may not be a critical issue for tenant or building owner, but understanding the sound data published by manufacturers is necessary in order to make an appropriate diffuser selection. Since diffusers are the system components in closest proximity to the occupants, they must be selected properly in order to produce suitable room sound levels.

The first thing to understand is the meaning of the NC numbers that manufacturers publish. NC stands for noise criteria. This is a single number that assigns an overall room sound level based on relative loudness and the speech interference level of a given sound spectrum. NC charts plot sound frequency (Hz) versus sound pressure level (dB). Sound pressure is the sound level measured in a space after some amount of sound power
has been absorbed by the environment.

Here are some recommended sound levels for common applications as found in the ASHRAE Handbook of HVAC Applications:

• NC20 - Concert and Recital Halls
• NC25 – Places of Worship, Music Rooms
• NC30 - Conference Rooms/Hospital Patient Rooms/Hotel Rooms/Meeting Rooms/Courtrooms with Unamplified Speech/Classrooms
• NC35 - Operating Rooms/Courtrooms with Amplified Speech
• NC40 - Open Plan Offices/Lobby Areas
• NC45 - Gymnasiums

NC15 is generally accepted to be total silence or the threshold of hearing for healthy adults. You might wonder why some manufacturers publish sound levels less than NC15. The purpose of doing this is to allow multiple products that may be individually inaudible to be added together to predict a combined sound level.

NC30 is typically the lowest sound level that can be achieved in most buildings without going to special lengths to sound proof the structure. NC30 is fairly easy to achieve in a suburban or rural setting, but much more difficult in an urban or industrial environment. Spaces requiring sound levels less than NC30 include broadcast and recording studios as well as opera and concert halls.

Although it’s been said that a noisy diffuser is good diffuser because you can hear it working, that’s not true. There are many issues that can cause diffuser noise to be audible including inlet conditions, neck-mounted dampers, and undersized or misapplied devices. Diffusers tend to make their highest sound levels in octave bands 4 (500 Hz), 5 (1000 Hz), and 6 (2000 Hz). These are known as the “speech interference bands” because they are the same frequencies we use when speaking. A noisy diffuser would therefore create a poor speaking environment and should be avoided.

The best way to avoid noisy diffusers is to select them for sound levels at least 10 NC points lower than the desired room sound level. This allows the diffusers to disappear into the background without contributing to the room sound level. As a general rule, diffusers should not be selected for sound levels greater than NC25 for any occupied spaces other than industrial applications.


For information on this topic/product, please contact Randy Zimmerman at rzimmerman@titus-hvac.com or Titus Communications at communications@titus-hvac.com.

Titus AHR Booth 2018

Trenton Yarbrough, national sales manager, reviews two innovative products in the Titus booth from the AHR EXPO held in Chicago.

Surface Mounting Options for Ceiling Diffusers

One of the more frequently asked questions we receive in application engineering is in regards to surface mounting Titus diffusers. When a ceiling grid is not present, surface mounting is specified and the installation questions arise. Linear diffusers are available with concealed mounting, square and rectangular diffusers with square or round inlets are not.

The most important thing to know about surface mounting is that it normally requires additional framing to which the units will be secured. We often receive calls for mounting instructions after the sheetrock has been installed which is too late to provide framing without removing the installed surface.

Titus mounting frames make installation of grilles, diffusers and other ceiling components in plaster and sheet rock ceilings as simple as inserting them in a standard T-bar type ceiling.

Framing requirements will vary from one job to the next, but there are some general guidelines and terminology we use.

Obviously installing screws in the face of a diffuser will work as it does for grilles but the duct return flanges behind diffuser edges are generally not available to provide a secure mounting base for screws. Also, many surface mount frames do not have a flat surface nor is there a screw hole fastening option available. Furthermore, screw fastening certainly does not enhance the aesthetics of the installed diffuser.

All sheetrock is mounted to ceiling joists. Joists are usually parallel to each other and spaced at two to three feet apart depending on local building codes, and in most cases, the framing for the diffuser can be mounted to the top of, and perpendicular to the joists. Screws are then used to mount the back pan to the framing. Framing members should be centered on the diffuser location to allow sufficient clearance for the diffuser inlet and associated duct. Additional care must be taken so as to avoid any protrusions or features that will occupy the space necessary for the framing on the rear side of the diffuser. Framing should also be at a depth that will allow the diffuser to firmly seat against the sheet rock. Most diffuser back pan heights are less than the depth of the joist. The sheet rock or ceiling surface is installed into an opening provided for the diffuser.

The diffuser core should be removed prior to installation to allow for screws to be installed in the top of the back pan transition; this is the flat portion on the rear of the back pan. Screws are then used to secure the back pan to the framing. It is helpful to use washers to prevent the screw heads from being driven through the back pan if the framing is not flush to the rear of the pan. In most cases the screws can be placed in a manner to not be visible from the occupied space after the diffuser core or face is re-installed.

As an alternative to the framing process, and one that we suggest if the ceiling surface has been installed without prior framing for the diffuser mounting, is to use our rapid mount frame. The TRM frame can be installed in the space between the joists following the installation of the ceiling.

 

The TRM replicates a standard ceiling grid module and a lay-in (type 3) frame diffuser. The diffuser can then be laid in the TRM frame. The TRM frame does add a border to the finished appearance of the diffuser, but also can be utilized as an access port to the space above the ceiling by simply pushing the diffuser up and out of the opening.

 

While the TRM does represent additional diffuser cost, the reduced labor requirement and flexibility of the installation sequence offers a distinct advantage.

The TRM is available in steel and aluminum and is ordered as a separate line item. Remember, when using the TRM frame, the (type 3) diffuser frame must be used instead of the (type 1) diffuser frame.


For information on this topic/product, please contact Mark Costello at mcostello@titus-hvac.com or Titus Communications at communications@titus-hvac.com.