Wednesday, February 22, 2017

GRD: Frequently Asked Questions

Titus encourages questions, as they lead to knowledge and a refinement of processes. It is understood that customers have varying requirements to meet job needs. This holds especially true for our largest offering, GRD products. With that said, we thought it would be worthwhile to explore common GRD inquiries and provide relevant application examples: 

Estimating Oversized Grille Performance

Grilles ordered with neck sizes larger than 48” are supplied in multiple smaller grille sectionals, and referred to as "oversized construction." Oversized grilles can be ordered to fill very large hole openings, up to the max size of 144” x 96”. To determine the performance of an oversized grille, we have to analyze the performance exhibited by each grille sectional. Please refer to page H48 of the current Titus catalog for illustrations showing the breakdown of grille sectionals.  

Example: We want to know the performance of a 96” x 96” oversized grille handling 2,000 cfm. We know the oversized construction will consist of four 48” x 48” sectionals based on the 96” x 96” neck size. Dividing the 2,000 cfm by 4 sectionals results in a cfm load of 500 cfm per 48” x 48” sectional. Finally, use the performance tables in the Titus catalog to determine what NC level and/or throw value the 48” x 48” grille will exhibit. The performance of the grille section is indicative of the performance for the entire oversized construction.

Using Supply Diffusers for Exhaust/Return Air Applications

Supply air diffusers can also be used for return air applications. When using a supply diffuser for return air, you have to make a slight adjustment to account for the increased pressure. Return air is now entering the smaller face area, instead of the larger neck area, which results in increased negative static pressure. Since pressure is increasing, so will the noise emitted by the diffuser. A safe rule of thumb is to convert the NC level of a supply diffuser to a return air application is to add 3-4 extra NC to the published NC value. 

Example: A 24” x 24” module OMNI with a 10” round neck can supply 436 cfm at 20 NC. In a return air application, the same OMNI will be able to exhaust 436 cfm at 23-24 NC. 

Sizing Grilles Based on the Free Area Requirement

Free area is the sum of the areas of all the space between the bars or blades of a grille, and is often expressed in square inches (in²) or square feet (ft²). FA is commonly used for supply and return grilles, but not ceiling diffusers. To determine the free area for the Titus grille in question, you must first locate the free area percentage for that product. The free area percentages for all Titus grilles and registers are listed in the Air Balancing Guide, located on the Titus website.


Once you have located the appropriate FA% for the model in question, you must then lookup the core area based on the nominal grille neck size. The Titus performance data lists the core area for all supply and return grilles. Multiply the core area by the FA% and the result is free area for that neck size in ft².

Example: A 22” x 22” neck size 350 grille has a core area of 3.14 ft². Looking at the Air Balancing Guide, the FA% for a 350 grille is 58%. Our resulting free area for a 22” x 22” 350 grille is 3.14 ft² x .58 = 1.82 ft².




Please direct questions toward Titus Communications (communications@titus-hvac.com) and/or Neal Holden, Titus' GRD Application Engineering Manager (nholden@titus-hvac.com).  

Tuesday, January 31, 2017

Chilled Beam Basics: Energy Savings 101

Chilled beams are just one part of an energy-efficient system. They need the correct primary air systems to save energy. To determine which system, we need to take a closer look at chilled beams and how they save energy.

Chilled beams take advantage of increased volumetric heat capacity of water over air. Water requires 1/3440th the volume to move the same amount of energy as air at the same temperature difference. This equates to 1/7th the energy to pump the water, versus the air, for a load in a standard HVAC system.

An active chilled beam has two distinct cooling components. The first component is the induced room air that is cooled by the chilled water coil, and the second is the primary air. The primary air will be discharged into the chilled beam through nozzles. As the primary air expands, exiting the nozzles, it will form a lower pressure zone around the nozzles. This low-pressure zone will induce air from the room over the chilled beam’s chilled water coil. The induced air will be cooled by the coil and provide sensible cooling. This is the component we want to maximize to take advantage of the pumping efficiency / volumetric heat capacity. If the primary air is supplied at a dry-bulb temperature below the space temperature, it will provide the second component of sensible cooling. This component is the same for a standard overhead air system. To summarize, we want to maximize the induced air. Another way to say that is the higher the induction rate, the greater the energy savings.

The amount of induced air is affected by the inlet pressure and nozzle size. A general rule of thumb is the smaller the nozzle, the greater the induction rate.

The primary air satisfies three requirements in the chilled beam system. It provides ventilation air, latent capacity and the energy to operate the chilled beams. We determined that to maximize energy savings, you want to minimize the required primary air.

In general, the primary air’s first requirement, ventilation, will not set the airflow. Minimum airflow set by ASHRAE 62.1 will not provide adequate latent capacity at standard commercial supply air temperatures to meet design loads. There are always exceptions, and design should be looked at on a case-by-case basis.

Latent capacity of the primary air generally is the driving factor that sets the airflow. Depressing the specific humidity level of the primary air will increase the latent capacity of the airflow. This will allow the system to provide less primary air. The goal is to balance the needs of the space with the minimum primary air and distribution energy. Ideally, the primary air system should depress the specific humidity to a level where the required primary airflow is equal to the ventilation requirements or the chilled beam’s minimum airflow to meet sensible loads and room coverage.

An additional advantage to reduced primary airflows is decreased reheat energy. In maximizing the energy efficiency of the system, the majority of the cooling load will be controlled by the chilled beam’s chilled water system. As the room load changes, the chilled beam’s chilled water can be modulated or shutoff to adjust room cooling. Due to the depressed specific humidity level and the constant volume supply of the primary air, the latent capacity to the room will not change, maintaining more consistent occupant comfort even during low sensible load times without the need for reheat to maintain temperature or humidity.

Reduced reheat and distribution energy are two ways chilled beams can improve the energy efficiency of a building design.


Please direct questions toward Titus Communications (communications@titus-hvac.com) and/or Ken Loudermilk, Titus' Senior Chief Engineer - Sales & Marketing (kloudermilk@titus-hvac.com).  

Wednesday, December 14, 2016

EcoShield


Titus has fielded many inquiries about our EcoShield liner. All literature associated with this product can be found on our website. The liner submittals show all of the ASTM & NFPA standards that the liner is in compliance with. EcoShield liners can be ordered as stand-alone rolls (seen in the table below):


The roll sizes above are the standard stock sizes, with custom sizes being available between the maximum roll widths of 60” in lieu of the standard 48” width. We also have EcoShield sample kits, which are packaged in a box that can have up to 8 liner samples. A custom insert highlights competitive advantages. Contact Titus Marketing for demo kits.

Some of the great benefits of EcoShield include:

·        Quiet operation: Cotton has excellent sound-absorbing qualities, and EcoShield meets the same acoustical performance of the Titus line of fiberglass-lined products.
·        Thermal protection: Outstanding insulation performance assists in conserving energy, without the potential health concerns associated with traditional fiberglass insulation.
·        High air-erosion tolerance: EcoShield meets the same standards as fiberglass. ASTM C1071.
·        Resists microbial growth: Treated with a patented EPA-approved fire retardant that limits fungus and mold growth. ASTM C1338, G21, and G22.
·        Resists dirt, debris, damage, and moisture: The durable non-woven facing provides resistance to dust, dirt, debris, moisture, and is available with foil facing as well.
·        No itch or skin irritation: Constructed of natural cotton fibers containing no harmful irritants and is safe to handle.
·        Exceeds Class A - Flame/Smoke: Surpassed Class A standards of 25/50 with actual EcoShield results being 5/10. ASTM E84.
·        Non-toxic: Patented fire-retardant treatment does not emit toxic fumes upon exposure to flame.

Airstream Surface

The Ecoshield surface that is exposed to the air stream is overlaid with a durable, fire-resistant facing that also provides additional strength. The liner facing is not only available in the black matte facing, but in foil facing as well in both ½” and 1” thicknesses. Ecoshield eliminates outgassing or Volatile Organic Compound (VOC) concerns, and includes an EPA registered anti-microbial biocide for mold and fungal inhibition that ensures the facing is safe for you and the environment.

Indoor Air Quality 

People have become more concerned about their IAQ when they have fiberglass in their HVAC systems. There has been a growing a trend toward eliminating fiberglass from the airstream.
Many owners and engineers require alternate liners in terminals and ductwork. Options for liners other than fiberglass are as follows:
·        Fibre Free™
·        SteriLoc™
·        UltraLoc™
·        EcoShield™

These liners remove fiberglass from the airstream, but there are financial/acoustical costs associated with them. Not having a liner would obviously be the least expensive of the options, but it would result in the highest acoustic penalty. Insulation is an excellent attenuator of HVAC sound.
Fibre Free™ is the least expensive of the liner options, but would increase the sound of the system by approximately 2 to 3 dB in each octave band.
SteriLoc™ covers the fiberglass fibers with foil scrim. They are a slightly higher cost alternative, but increase the sound of the system by approximately 4 to 6 dB in each octave band. There is also the potential that the foil scrim can get torn during installation, since it is a duct-board liner which is much denser and would expose the fiberglass to the airstream.
UltraLoc™, which sandwiches the fiberglass fibers between sheet metal, is the most expensive of the liner options and by far the heaviest. The sound increase of a double-wall terminal is dependent on unit design and airflow characteristics.
EcoShield™ allows you to take the fiberglass out of the airstream with no additional cost for the liner.
Suggested Specification
The terminal casing shall be minimum 22-gauge galvanized steel (20 gauge for fan-powered terminals), internally lined with ½-inch matte faced, natural fiber insulation that complies with ASTM C 1071 and NFPA 90A. The liner shall comply with ASTM G21 and G22 for fungi and bacterial resistance.
(Liner facing and thickness can be replaced in the above specification text to meet the different EcoShield types.)

Please direct questions toward Titus Communications (communications@titus-hvac.com)

Friday, December 2, 2016

Fan Filter Diffusers - The Solution for USP 797 and USP 800 Pharmacies

Fan filter diffusers (FFD) were introduced to the market in 1984 as a new solution in cleanroom applications. In situations where the use of conventional ducted modules is impractical or the air supply has insufficient static pressure to move the air through a HEPA filter, fan filter diffusers provide an excellent alternative.

In cleanroom design, the primary factor is contaminant removal and the cleanliness level, so moving the air is a major challenge. The volume of recirculated HEPA filtered air, including conditioned air to handle high cooling loads that are typical of many cleanrooms, can range from less than twenty to more than five-hundred air changes per hour. Fan filter diffusers are designed to address this situation by producing a laminar or unidirectional flow of clean air traveling downward at a velocity of 90-feet per minute, as measured 6” below the filter face.

Cleanroom manufacturing processes require a high level of air filtration to protect the raw materials and the end product from particulates that can damage the product or cause it to fail in use. Utilizing fan filter diffusers in cleanrooms prevents the infiltration of contaminants and also provides for the removal of particles generated by people and equipment in the work space. Typical cleanroom applications that utilize fan filter diffusers include:

  • Semiconductor Manufacturing 
  • Pharmaceutical Manufacturing 
  • Medical and Dental Device Manufacturing 
  • Digital Device Manufacturing 
  • Food Processing Plants 
  • Computer Manufacturing

Titus’ Fan Filter Diffusers … Low Energy, Low Sound and Low Profile

Titus offers a complete line of fan filter diffusers that can be used for new design or upgrading existing cleanroom environments. Each Titus FFD is a self-contained fan filter module that includes HEPA or ULPA filter, pre-filter, and fan speed control. Air circulation is maintained by using a lightweight, forward-curved fan, powered by a 120V or 277V 60Hz motor. Motor speed is adjusted by the solid-state speed control that is mounted on the top of the housing. Patented baffling technology ensures uniform airflow across the filter face and attenuates sound for one of the quietest fan filter diffusers in the industry. The room side replaceable option (R) provides quick and efficient replacement of the HEPA or ULPA filter while the diffuser remains in place. Room side replaceable diffusers are ideal for plenum areas with limited space or applications that require frequent filter changes.

Titus’ fan filter diffusers are also available with an electrically commutated motor (ECM) option. These units dynamically adjust themselves to maintain the set airflow, compensating for changes in static pressure, filter loading or other local conditions. Titus fan filter diffusers with an ECM can easily maintain cleanroom air levels exceeding the Institute of Environmental Sciences and Technology’s recommended practices. Airflow is maintained so constantly and consistently that the need for future balancing is greatly reduced. The ECM option, along with the patented baffling system and forward curve fan, makes Titus fan filter diffusers intelligent, energy efficient and ultra-quiet.

Titus’ Fan Filter Diffuser Models:

·        FFD - Standard construction, PSC motor, HEPA or ULPA filters, 2’ x 2’, 3’ x 2’,  4’ x 2’ sizes
·        FFDE - Standard construction, ECM motor, HEPA filter, 2’ x 2’, 3’ x 2’,  4’ x 2’ sizes

·        FFDR - Room side replaceable filter, PSC motor, HEPA filter, 2’ x 2’, 3’ x 2’,  4’ x 2’ sizes
·        FFDER - Room side replaceable filter, ECM motor, HEPA filter, 2’ x 2’, 3’ x 2’,  4’ x 2’ sizes

·        FFDRA - Room side replaceable filter and PSC motor, HEPA filter, 2’ x 2’, 3’ x 2’,  4’ x 2’ sizes
·        FFDERA - Room side replaceable filter and ECM motor, HEPA filter, 2’ x 2’, 3’ x 2’,  4’ x 2’ sizes


Please direct questions toward Titus Communications (communications@titus-hvac.com) and/or Titus' CB/Critical Environment Product Manager Matt McLaurin (mmclaurin@titus-hvac.com)

Friday, October 28, 2016

CT Linear Bar Grille Sizing

A common subject we deal with in application engineering involves the sizing of model CT linear bar grilles. Common inquiries include “If I want the outside dimensions to be        , how long of a unit should I order?” and “My customer needs to know how big of a hole to cut.” Although the catalog and submittals provide dimensions, we thought this might be a good opportunity to expound on the subject. It is helpful to refer to the CT border and frame details on Titus product catalog page F51.

All grilles are undersized from the nominal-duct dimensions in order to fit ductwork, and the linear units are no exception. The stack head is the part of the grille that is installed into the wall opening and associated ductwork or plenum. We start our sizing from the inside of the stack head because this is the business part of the unit through which the air passes and performance data is consistent regardless of the border width.

The inside of the linear bar grille stack head is undersized from the nominal, or duct dimension by ¾”. The floor frames, type 5 and 6, are the exception at 3/8". The undersized dimension represented in our marketing literature is D-¾”, or “Duct” minus ¾”. If a dimension is specified as 12, the inside of the stack head will be 11-¼”; This applies to the length and width of a unit. The outside or overall dimension is 11-¼” plus two border widths (Plus two mounting-frame widths for the combination frames that use both a border and frame).

Cut dimensions for mounting the units can vary from the loose fit of the specified D dimension to a tight fit of D-5/8”. The tighter fit is beneficial to the screw-mounting option as it provides the most overlap or “meat” into which the screw is installed, particularly for sheet-rock surfaces. The loose fit of a D cutout is flexible and should be used for combination frame & borders, spring-clip mounting, concealed-mounting, or to provide clearance for a plenum boot -- by others -- to be installed. Titus does not provide plenum boots for linear bar diffusers.

Floor frames (Type 5, 6 & 15) and combination frames that utilize a mounting frame (Types 1 through 4) are a little different in that the outside of the stack head or mounting frame correlates exactly to D. For these units, the cutout should be slightly oversized at D+1/8” to provide clearance for the weld beads at the corners of the frames.

There are two particular notes I would like to make involving narrow frame styles 7, 11 and 12. First, the type 11 and 12 frames offer a screw-mounting option (A). When the A option is used, it is important to consider upsizing the grille or making sure that the tight cutout used will provide a secure base for screw-mounting. If the D dimension is used, the screw holes provided in the frames may coincide with the opening; Installation becomes much more complicated. Concealed mounting is the preferable mounting option for these frames.
The type-7 frame does not offer the screw-mounting option, so a concealed fastening must be used. This frame style was originally designed for the type-4 combination frame, but the narrow border width makes it attractive to those desiring the least amount of exposed grille for aesthetic purposes. You will note that because of its primary use as the core of a combination frame, the D dimension actually falls outside the overall (O) dimension. Therefore, a unit size of 12" x 12” should not be installed in a 12" x 12” cutout. The tight fit cutout of D-1/2” should be used, or the unit needs to be oversized by 1/2” if the D cutout will be used.


Please direct questions toward Titus Communications (communications@titus-hvac.com) and/or Titus' GRD Product Manager Mark Costello (mcostello@titus-hvac.com)

Tuesday, September 20, 2016

The Displacement Ventilation Solution


Displacement Ventilation (DV) is a cost-effective means of providing an optimal indoor environment by delivering cool supply air directly to the occupants in a space.

What are the benefits?

Displacement ventilation systems offer an effective, energy-efficient way of delivering freshly conditioned air and removing airborne pollutants to improve comfort and air quality. Indoor air quality is improved since the rising thermal plumes carry away contaminants toward the ceiling exhaust. Displacement ventilation can improve acoustics because of the low background noise caused by low supply air velocities and the remotely located cooling and delivery equipment.

How does it save energy?

There are several reasons behind the cooling energy savings with DV. First and foremost, the higher supply air temperature of 65°F greatly increases the potential for free cooling. Secondly, the higher supply air temperature also increases the efficiency of mechanical cooling equipment.

How to apply DV units?

Supply air must reach the occupied space at velocities comfortable for the occupant(s). The zone closest to the displacement ventilation unit with velocities exceeding 50 fpm is called “Near Zone” or “Adjacent Zone.” To achieve maximum room occupancy for each job application, the near zone has to be adjusted to a minimum. To ensure good comfort in the room, a flexible pattern controller pattern makes it possible to alter the adjacent airflow pattern.

How does the new Titus pattern controller work?

Titus engineering utilized their recent experience with displacement products and projects in which this technology was applied. The new pattern controller is an evolution from a single pattern controller to a cluster of metal controllers. Not only will this be a product quality improvement, it also simplifies the controller adjustment at the job site. Performance is not affected by the product change; so you will be able to continue using the performance data listed in the catalog. Titus was able to maintain the same application data by upgrading the deflection of the perforated area on the front covers.

We improved this product family to enhance quality and provide the most flexible product on the US market today. 


Please direct questions toward Titus Communications (communications@titus-hvac.com) and/or Meghna Parikh, Titus' FC/BC/DV Product Manager (mparikh@titus-hvac.com). 

Friday, August 19, 2016

The Case for Chilled Beams in Schools


We all know the importance of comfort in schools and comfort’s relationship with student performance. While temperature gets the lion’s share of attention, equally important are noise, humidity, and ventilation. Efforts to update standards to address noise, humidity, and ventilation have made it harder for traditional HVAC equipment to establish and maintain comfortable learning environments in schools.
Enter chilled beams.
In a chilled-beam system, zone-based hydronic heating and/or cooling devices complement the primary air ventilation system, enabling the optimization of all heating, cooling, and ventilation functions. Chilled beams are quiet, can reduce energy consumption and maintenance, and take up less ceiling-cavity space while contributing to conditions that increase occupant performance.
Noise
Think back to when you were a kid in math class. There probably were a number of distractions: a class clown, paper airplanes, someone passing notes.
One disruption that does not get the attention it deserves is unnatural or excessive background noise, which studies have shown can significantly hinder student performance. Conventional HVAC systems rarely meet prescribed background-noise-level requirements. ANSI/ASA S12.60, Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools, requires a maximum background-noise level of 35 dBA (about NC 27)—difficult, if not near impossible, to attain with traditional classroom HVAC equipment. Chilled beams do not rely on internal motors or blowers to recirculate and recondition room air and, thus, can be utilized to maintain HVAC background-noise levels in accordance with ANSI/ASA S12.60.
Humidity and Ventilation
HVAC systems that modulate supply airflow rate during occupied operation often do not maintain outdoor airflow rate within the requirements of ANSI/ASHRAE Standard 62.1-2013, Ventilation for Acceptable Indoor Air Quality. Additionally, with all air systems, minimum ventilation airflow rate establishes minimum supply airflow rate. During off-peak operation, this airflow rate exceeds what is required for cooling, necessitating the reheating of supply air before it enters a space.
Active chilled beams served by a dedicated outdoor-air system (DOAS) utilize ducted variable-temperature outdoor air to induce room air through an integral hydronic heat-transfer coil. Classroom cooling/heating demand is met by modulation of the rate of water flow through the coil while the rate of airflow remains constant. The coil’s effect on space conditioning allows ducted-airflow temperature to be reset seasonally, resulting in significant reheat energy savings.
Active beams can be located either within a ceiling grid or floor-mounted adjacent to an outside wall. When active beams are floor-mounted, ventilation air can be delivered to a classroom in a displacement-ventilation manner. This method of delivery can reduce classroom carbon-dioxide levels and the resultant risk of the spread of respiratory diseases by more than 50 percent.
Additional Benefits
Not only do chilled beams benefit students by being quieter and more adept at adjusting to fluctuating humidity and heat conditions, they benefit schools by reducing costs. While most conventional HVAC systems depend on the delivery of large volumes of air to condition classrooms, chilled-beam systems reduce ducted-air requirements by up to 60 percent by relying on their integral heat-transfer coils to offset the majority of space sensible-cooling and heating requirements. And because water is more efficient for space cooling and heating than air, chilled beams use considerably less energy overall than do other options.
In DOAS, chilled beams reduce classroom ducted airflow to the rates required for space ventilation and latent cooling, which allows for a constant volume of ventilation air. Also, they can contribute to the achievement of LEED certification through Energy and Atmosphere Credit 1, Optimize Energy Performance, and Indoor Environmental Quality Prerequisite 1, Minimum Indoor Air Quality Performance.

(This article was published by HPAC Engineering to http://hpac.com/air-conditioning/case-chilled-beams-schools.)


Please direct questions toward Titus Communications (communications@titus-hvac.com) and/or Ken Loudermilk, Titus' Senior Chief Engineer - Sales & Marketing (kloudermilk@titus-hvac.com).