Seeing the Big Picture in Building Design

By Al Fullerton, Systems Leader, Trane

To maximize efficiency of the entire building It’s important to first consider how to make the entire system more efficient before going granular and looking at individual pieces of equipment.

In commercial building design, individual pieces of heating, ventilation and air conditioning (HVAC) equipment are often selected based on their efficiency. It’s natural to want to choose the most effective solution, and many times we consider this through the performance of an individual component.

But is this really the best way to achieve the most efficient building performance?

It may seem counterintuitive, but the most efficient piece of equipment may not always result in the most efficient building or system performance. There are many variables that contribute to optimized building performance. It depends on how the building is being used and occupied, how the various pieces of equipment in the building interact and work together, and what the goals are for the facility.

This makes it important to look beyond the efficiency of a single piece of equipment and instead consider building performance and efficiency — seeing the whole as greater than the sum of its parts.

Taking this approach can result in improved energy efficiency and operational cost savings, and play a role in meeting goals your customers may have for sustainability, energy consumption and efficiency.

Why is whole building design a better approach?

“The whole is greater than the sum of its parts” is a common concept. Applying it to building design can provide significant value and results. For building owners and managers, it can result in improved energy efficiency, lower first cost and overall cost savings. For engineers and contractors, understanding and meeting customer needs with a systems-design approach can provide a competitive edge.

Rather than asking which individual pieces of equipment are the most efficient, the question becomes how to make the entire system more efficient? Resisting the urge to go granular immediately — and instead taking this systems approach upfront — helps maximize efficiency of the entire building.

It starts with understanding what the building owner or facility or property manager is trying to achieve in their facility. What building outcomes are being sought? Is the driver LEED certification, a net-zero building, a corporate sustainability goal or other benchmarks or regulations?

Next, consider how the building will be run and when it will be occupied. The needs of a commercial property differ greatly from the needs of a hospital, for example. Knowing how the building will be used provides a better understanding of full-load and part-load performance, which helps determine what equipment and systems are best suited for the building.

From there, move backward into what building systems best match these goals and needs. In addition, it’s important to look at how the various building systems — from plumbing, lighting, security and HVAC — interact and best work together to optimize building efficiency.

Consider this example: Many chilled water systems are designed to pump 2.4 gallons of water every minute for every ton of chilled water to be produced, and 3 gallons per minute of water for every ton of coolant to be made. If a chiller is selected based on these conditions, the end result is a lot of water being pumped around a building. By contrast, using a whole system approach can save significantly in the amount of water and energy used. While in this option the chiller may initially look less efficient, it actually uses much less pumping energy — especially at part-load conditions — and results in a much more efficient system-level performance.

As more organizations and states enact increasingly stringent energy-efficiency goals and regulations, the industry recognizes that systems-level efficiency provides a great opportunity for improvement in this area. The Alliance to Save Energy made a case for using a systems-level approach to improve energy efficiency in a recent white paper, “Greater than the Sum of its Parts.” The white paper notes that in addition to reducing energy use and associated costs to consumers, a systems approach has the potential to achieve significant non-energy benefits, including reduced greenhouse gas emissions, improved grid reliability and resilience, water savings, extended equipment life, and increased occupant comfort and productivity. Studies have estimated that the quantifiable non-energy benefits can add 25 to 50 percent to the total monetary benefits of energy efficiency.

Key strategies for a systems-level approach

Consider these key strategies that can help in successfully implementing a systems-level approach in building design:

  • Understand the utility cost structure. Don’t choose building systems and equipment without having a clear understanding of the utility rates and structure for a specific building and location. Understanding the utility rate structure — which often includes consumption charges and demand charges — allows for a more accurate analysis of building performance based on how the building will be occupied and used. In some areas, demand charges can comprise up to 75 percent of the monthly utility bill. Knowing this can help in choosing the most efficient system from a utility bill perspective, such as taking advantage of the load-shifting capabilities of a thermal storage system. It’s often helpful to consult a partner who offers expertise in building systems and equipment, as well as in utility rate structures and billing.
  • Consider the total budget. Selecting the building systems and equipment that will best provide optimized efficiency and performance for a specific building also hinges on the budget — both upfront and long-term for staffing and maintenance. Selecting a system that requires less long-term maintenance can help an organization save staffing costs in the long run.
  • Understand the needs. Asking the right questions about how the building will be used and occupied is a critical consideration in choosing the systems and equipment that will provide the most efficient performance. For example, it typically takes several years after construction for most data center facilities to operate at full load. However, those early years of part-load operation are often not considered in building design when choosing the systems that will offer the most efficiency. It’s important to consider how systems and equipment will perform under partial loads.
  • Use a modeling program. Using a building modeling or energy simulation program in building design contributes to sound decision making — and it can pay off in improved energy efficiency and performance. Modeling allows you to optimize the systems from an energy and utility bill perspective before construction even begins. It’s important to model against the potential optimized performance of the whole building and its systems, rather than modeling against performance of individual components.  

How can it pay off?

While improved energy efficiency and utility savings are significant benefits of system-level design, using this method can pay off in other ways.

Better fresh air ventilation or better acoustic levels in the building are examples of secondary benefits that can result from proper system design. These features can result in fewer complaints, as well as in more productive occupants.

Some systems also offer benefits for ease of maintenance and reduced risk down the road.

It is possible to use a single provider with expertise in equipment and system design and building optimization. This can help reduce risk and ensure a more efficient design and planning process. A knowledgeable partner can also help assess the best opportunities for efficiency.

Seeing the sum instead of the parts

What is it that your customers want to achieve in their building, and what is the best way to get those results? Considering these questions at the start of the design process can help in choosing the systems that are best suited for the job — and help your design stand out.

A building design process that focuses on the efficiency of the whole building — rather than on the efficiency of individual components — can improve energy efficiency and help you better meet the changing priorities of building owners.

Author Bio
Al Fullerton is Intelligent Systems Leader for Trane, a leading global provider of indoor comfort solutions and services and a brand of Ingersoll Rand. In this role, Al leads a team of engineers focused on expertly applying Trane Systems. Al has worked in the HVAC industry since graduating from the University of Cincinnati with a bachelor’s degree in Mechanical Engineering in June of 1981.  

 

VFD APPLICATION GUIDELINES

By Colmac Coil

Background

The application of Variable Frequency Drives (VFDs) in heating and cooling units is becoming more common every day.  VFDs work by converting an AC voltage to DC voltage and then pulsing the DC voltage to simulate an AC sine wave at the required frequency to control motor speed. VFDs are an effective way to reduce energy usage but Colmac’s experience has shown that there are several design considerations to be accounted for in order to produce a successful application. These considerations are particularly important for extending motor life by reducing the potential causes of bearing currents and insulation breakdown that may arise with the use of VFDs.

Failure Modes

Bearing Current Failure – Improperly configured VFD systems can contribute to high shaft voltages which may result in Electric Discharge Machining (EDM). EDM occurs when voltage levels on the rotor/shaft exceeds the dielectric rating of the bearing lubrication and an arc is drawn across the bearings to ground. Every time this arc occurs a pit is created in the bearing race which, over time, will cause a fluted pattern in the bearing race. As the EDM continues to deteriorate the bearing surfaces the motor will experience vibration, increased noise levels, overheating, hard starts, overloads, and eventually, bearing failure.

There are several ways to mitigate the effects of EDM, however, these do not address the root cause. Such solutions include insulated or ceramic bearings and shaft grounding systems. While effective for mitigating EDM, these can have a high initial cost and represent an ongoing maintenance burden for the system.

Insulation Failure – The DC voltage pulses produced by VFDs travel down the conductors to the motor and can be reflected back to the drive. The reflected wave can increase in magnitude to the point where a partial discharge can occur (corona). This corona effect falls short of an actual insulation breakdown but can act to produce ozone which leads to carbon tracing and insulation degradation. Left uncorrected, the corona effect will eventually result in insulation failure and equipment damage.

Application Recommendations

System – When utilizing VFDs care must be taken to coordinate all components and to confirm their compatibility. The system designer and installing electrical contractor are responsible for designing the VFD electrical system to protect the specific motor(s) being controlled by the VFD.

Cabling – Conductors supplying motors should be rated and sized appropriately for the motor load, voltage drop, and environmental conditions. Line lengths between the VFD and motors(s) should be minimized wherever possible. Shorter line lengths will reduce the magnitude of reflected waves and, in general, benefit the longevity of the installation. Always follow the VFD and motor manufacturer’s specifications when selecting and installing conductors for a VFD installation.

Motors – Colmac motors are specified to comply with the National Electrical Manufacturers Association (NEMA) standard MG1 part 31 requirements for inverter duty motors.

Grounding – It is essential the electrical system, building steel, motor and VFD be properly grounded. The National Electric Code (NEC) describes the minimum requirements for grounding and bonding an electrical system for safe operation. In addition to providing a ground from the drive chassis and motor frame to earth ground, Colmac recommends a separate ground conductor from the motor frame to the VFD ground bus. Proper grounding is a critically important means of mitigating reflected waves and bearing current failures.

Carrier Frequencies – Colmac recommends setting the drive carrier frequency as low as possible (typically 2 kHz). Lower carrier frequencies result in higher levels of audible VFD noise but will help to reduce destructive bearing currents.

Motor Speed – Generally it is not recommended to over-speed motors or to operate motors at less than 25% of the motor rated speed.

Filtering – The VFD’s DC output waveform is typically jagged and can be strongly influenced by the electrical equipment it supplies and the length and type of cables used to supply that equipment. It is important to keep this waveform within a safe range to protect both the VFD and the supplied equipment. External filters can be applied to the line and load side of the VFD to smooth out the DC waveform and protect the system from damage. In general, line side filters protect the VFD while load side filters protect the motor. Load side filters can extend motor life by decreasing bearing wear and by lowering the motor operating temperature. Three common types of load side filters are available today. These are Load Reactors, dV/dT filters, and Sine Wave filters. dV/dT and Sine Wave filters are more effective than Load Reactors at reducing reflected waves and voltage spikes. The use of dV/dT or Sine Wave filters ensures the longevity of the installation by ENG00020282 Rev 0, 04‐13‐18 ‐ Page 3 of 3 mitigating reflected waves, voltage peaks, and other potentially damaging transient effects. Colmac requires load side dV/dT filters or Sine Wave filters on all VFD applications.

Conclusions

There are many factors that can contribute to the success or failure of VFDs applied to Colmac equipment, most of which are the direct responsibility of the system designer and installing electrical contractor. The general design requirements listed above represent the minimum criteria for proper VFD system design. Care should be taken to follow all the drive manufacturer’s recommendations and all applicable electrical codes and standards.

References

(1) http://www.greenheck.com/library/articles/58

(2) http://literature.rockwellautomation.com/idc/groups/literature/documents/in/drives-in001_-en-p.pdf

(3) http://literature.rockwellautomation.com/idc/groups/literature/documents/wp/drives-wp016_-en-p.pdf

(4) http://literature.rockwellautomation.com/idc/groups/literature/documents/wp/drives-wp019_-en-p.pdf

(5) https://library.e.abb.com/public/fec1a7b62d273351c12571b60056a0fd/voltstress.pdf

(6) http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestReleased&noSaveAs=0&Rendition=Primary&dDocName=AP043001EN

Four Ways to Maximize Energy Procurement Savings

By Drew Fellon, business leader for energy supply services, Trane

 

It’s well-known that energy costs are always one of the most significant portions of a commercial building budget. Finding ways to reduce that spend can be tricky, but there are ways you can impact it: reduce the amount of energy consumed, change the time of day energy is used, or reduce how much you pay for that energy.

Typically, reducing energy consumption is the go-to solution many building owners and energy managers use in an effort to reduce costs and improve sustainability. While this is an impactful way to decrease energy spend, there’s another, less-conventional strategy, that is often overlooked — even though it can yield significant savings — energy purchasing.

The obvious, though less common, solution is gaining traction in the industry as owners and managers explore ways to reduce their energy spend budgets. Developing a strategy for examining and assessing your energy procurement options can help you make the most of your commercial building budget.  

Consider these energy procurement best practices to help streamline the energy supply process, maximize savings and optimize efficiency in your next commercial building project.

Tip No. 1: Engage a knowledgeable partner

Energy procurement is a complicated process, compounded by the many factors that impact energy rates. Working with a reputable and knowledgeable partner makes the process easier — and can save your company money.

Energy procurement and management companies are powerful resources that can help you avoid spending too much on energy. These companies have long-standing supplier relationships and market intelligence capabilities that they leverage as they work with you through the procurement process and can assist you in getting the best deal possible. Using energy price forecasting, regulatory and legislative monitoring, and years of energy industry experience and contacts, an energy procurement and management firm can help you make insightful decisions to reach your company’s goals.

When choosing to engage an energy procurement and management company, select an experienced partner with insight into the full supply chain and industry pricing structure. This organization can provide visibility to the tens of thousands energy transactions taking place annually. Consider working with an independent advisor without ties to a specific energy company or market. This independence helps create loyalty to you, not the energy supply company, and will provide transparency throughout the procurement process.

The right procurement and management partner can help you navigate the energy purchasing waters — and prepare your company for trends that may impact the industry down the road.

Tip No. 2: Consider your goals

Saving money is typically the top priority for most energy and supply chain managers examining their energy procurement options. But as customers demand more efficient, environmentally conscious solutions for their buildings, many energy and supply chain managers are prioritizing sustainability and the use of renewable energy. When it comes to reaching these types of goals, you need to look beyond price in the purchasing process. It all comes down to what you’re trying to achieve.

If the goal is to reduce energy costs by 10 percent, then purchasing renewable energy is likely not the solution. And if you are hoping to reduce the company’s carbon footprint, you’ll need to buy a certain type of energy that may not always have the lowest price tag. All of which is to say, that putting sustainability first, can look very different than your typical energy procurement process and sources.

Because many energy contracts are long term (between 10 – 20 years), it’s important to take a comprehensive, enterprise-wide approach to buying renewable energy solutions. If your enterprise has buildings or operations in many states, you can achieve more buying power when you coordinate efforts.

Make sure you’re considering the total end cost of an energy contract. There are many factors that affect the final cost of an energy contract, and this may not be clear in every situation. An energy procurement and management firm can help you understand the total cost of the contract structure — not just the initially quoted supply price.

Tip No. 3: Link supply with demand

Before entering into a supply contract, you should fully understand all the factors that influence energy demand in your building — including the supply and demand relationship. Pay close attention to how much energy your building or enterprise uses, taking time to look at both prior and forecasted usage, to determine how much energy to buy.

It is imperative that the supply chain, which drives purchasing, communicates with the operations staff, who oversees day-to-day use of building facilities. Otherwise, the energy manager or supply side personnel may assume that because X amount of energy was used last year, X amount of energy will be needed again next year. When in reality, operations may plan to install a new production line or more energy efficient equipment that will impact the facility’s energy demand.

If your organization is going to take measures to reduce peak demand, you need to make sure your energy supply contract allows you to benefit financially — rather than potentially being penalized by your supplier. Demand-side reduction efforts should be negotiated into your supply-side contract. It’s also important to run a competitive bid process every time you seek a new supply contract, rather than allowing your current supplier to set the price. Doing so will help you secure the best deal for each new contract.

Tip No. 4: Plan ahead

Another common pitfall in energy procurement is waiting until just before the current contract expires to start looking for a new one. The energy market is seasonally cyclical and impactful market events can drive prices up or down for short periods. To avoid paying too much for your next contract, get an early start and take time to really dig into your options and review pricing. This is where working with an experienced energy procurement and management firm can yield big returns. Tracking the energy market daily and understanding how certain events will impact pricing over time are both critical to long-term buying success.

If your organization requires stakeholder approval of energy contracts, be aware of that and secure that approval in advance. This allows you to move quickly when the time is right, so you can lock in the best price. Not having the approval process in place could translate into delays and lost opportunities in terms of pricing, as prices are often only valid for a short period of time.

Purchasing with strategy

Your energy purchasing strategy is dependent on many things, most of which are out of your control. Weather, government regulations, demand charges, and new energy developments are all issues that can impact pricing for commercial customers. Taking control of your procurement options with thoughtful research, meaningful partnerships, conscious goal setting and extensive planning can help you make the right purchasing decision for your building. And remember that you don’t have to do it alone. Working with an experienced energy consultant can help you streamline the energy supply process to increase your savings.

Advantages of double-wall brazed plate heat exchangers in potable water applications

By: SWEP North America

Brazed plate heat exchangers (BPHEs) are one of the most efficient ways to transfer heat.  They are designed to provide unparalleled performance with the lowest life-cycle cost. Choosing brazed technology for your next heating or cooling project will bring many benefits, including savings in space, energy, and maintenance across HVACR and industrial applications.  BPHEs are quickly winning ground, thanks to their many advantages over older technologies (i.e. plate & frame, shell & tube), and consistently deliver successful results in many types of applications and projects.

BPHE technology embraces double-wall models suitable for a wide range of applications such as hydronic heating, district heating, radiant floor heating, gas boilers, solar domestic hot water systems, snow melting, heat pumps, and domestic and potable water heating systems.  They are suitable for many industrial applications too, including food, pharmaceuticals, chillers, transformer oil cooling, and lubricating oil cooling. Double-wall, high-quality BPHEs combine the high efficiency and compactness of the BPHE with the advantages of double-wall technology.  Double-wall BPHE technology ensures that liquids do not mix and makes any internal leaks visible – important factors in applications where safety is a priority.

While double-wall BPHEs are well established in European installations, they have also already been proven in applications in North America.  One example is a biomass application for a large pellet manufacturer in the US, where a solution for cooling gearbox oil was being sought. Traditionally, the oil was cooled with a fan coil that lost energy to the atmosphere.  Installing a double-wall BPHE instead enabled the energy to be captured from the hot oil and used to heat domestic hot water. The energy saved with this BPHE solution was around 27,000 kW per year (92127834 Btu/hr.), giving the end user payback in 20 months.  In another North American case, double-wall BPHEs provided an optimized solution for a leading water heater manufacturer. Here, they were used in instant water heating applications and domestic hot water for tank heating. When combined with a BPHE, the boiler need not heat the water to such a high temperature to achieve a suitable temperature for the end users.  BPHEs have therefore been able to displace older shell & tube technologies in these types of applications. The double-wall BPHE can heat water to the desired temperature so rapidly and effectively that it is not only more energy efficient, but also imposes a smaller load on the boiler.

Above all, however, is the huge benefit of double-wall BPHEs in preventing water contamination in potable water applications.  In the Netherlands, for example, the government requires double-wall technology in district heating networks. On safety grounds, this technology has been used in a large majority of tap water heater installations over recent decades.  At first glance, the heat transfer task in this case does not appear particularly complicated. However, there are two challenges. First, Dutch law prohibits single-wall heat exchangers in tap water applications with heat loads over 45 kW (153546.39 Btu/hr.).  Second, the maximum pressure drop on the hot water side must not exceed 15 kPa. The double-wall BPHE has been proven to solve this problem in the most efficient and reliable way possible. Should a leakage occur, for example due to corrosion, water will seep out between the vented double walls to the atmosphere.  The water seeping out from the BPHE gives a visual alarm that something is wrong. Contamination of the tap water by the heating water delivered by the energy company can therefore be prevented. The double-wall philosophy could assure the quality of the tap water for all European citizens, but the Netherlands is still the only market to have adopted this very useful technology to a significant extent.  However, awareness of the technology is increasing in other countries. The German government, for example, recommends double-wall technology in tap water applications without making it a legal requirement.

When considering double-wall BPHE suppliers, look for those combining extensive expertise with a wide product range.  If you are also seeking the additional security of third-party verified performance, check that your BPHE supplier can offer AHRI-certified double-wall products.  AHRI’s certification programs are well-recognized performance verifiers for heating, air conditioning, and commercial refrigeration equipment. Products connected to a program are tested annually by independent third-party laboratories, contracted by AHRI, to verify that they conform to performance ratings specified in data sheets and selection software.  This enables buyers to evaluate and make a fair comparison when selecting products for their HVAC installations.

 

Conclusion

Double-wall BPHEs are designed to deliver high thermal efficiency while at the same time providing a leak detection feature – this proves to be an excellent solution for potable water applications.  Contact SWEP today to find out more about our range of double-wall BPHEs and how they can provide optimized solutions for your applications!

 

Ice Rink Update

Technical Safety BC’s recent report on the Fernie Arena tragedies underlines the safety risks inherent with ammonia ice plants. A small leak in a chiller tube caused a 9 lb. release of ammonia into the mechanical room which quickly overcame those working there.

To quote TSBC, “Ammonia releases from refrigeration systems can cause injuries to employees, emergency response personnel, any public using the facilities and those living in communities surrounding the facilities.  When released from a refrigeration system, ammonia vaporizes into a toxic gas. It is very corrosive, and exposure to it may result in chemical-type burns to skin, eyes, and lungs. It may also result in frostbite, since liquid ammonia’s boiling point at atmospheric pressure is -28°F. Ammonia has a high affinity for water and migrates to moist areas like the eyes, nose, mouth, throat, and moist skin.  Exposure to low concentrations can cause headaches, loss of the sense of smell, nausea, and vomiting. Higher concentrations result in irritation to the nose, mouth, and throat causing coughing, wheezing and damage to the lungs. Very high concentrations of ammonia can be immediately fatal.

Ammonia is flammable and extremely reactive as it readily combines with other chemicals to form other potentially harmful substances or explosive mixtures.  Material commonly found in refrigeration machinery rooms such as oils can react with ammonia increasing the fire hazard. In addition, strong oxidizers, such as chlorine or bleaches, can form explosive mixtures when they come into contact with ammonia.”

Work Safe BC calls ammonia levels of 300 ppm or more to be, “Immediately dangerous to life and health”.

The Trane white paper on Ammonia-Free Ice Rink Refrigeration, shows a leak of just a half pound is enough to raise the ammonia concentration in a typical equipment room above the 320 ppm RCL (Refrigerant Concentration Limit). Also notice it would require 718.8 lbs. of Trane’s R513A synthetic refrigerant to reach our 72,000 ppm RCL (well above the charge we have in our entire system).

Trane packaged chiller systems dominate the air-conditioning marketplace. As well our chillers are used in many institutional, industrial, laboratory, and critical cooling and heat recovery applications. Trane has built chiller systems for over a hundred years – it’s our bread-and-butter.

We are here to help you transition to safer, cost-effective and efficient ice rink chilling systems.

by Walter Linck

Vertical Projection Models Now Available on HHP2 Series of Heaters

We are excited to announce that our vendor partner, Hazloc HeatersTM, announced the addition of vertical projection models on the HHP2 series of steam and hydronic unit heaters.

The HHP2 series of heat-exchanger unit heaters is designed for rugged industrial applications in steam, hot water, glycol or other fluid circulating heating systems. The HHP2 series is designed for pressures and temperatures up to 450 psi and 550 °F respectively in single-pass and multi-pass core configurations. HHP2 heaters meet ASME requirements with a national CRN to conform to the Safety Codes Act.

The HHP2 series includes 16 model choices of horizontal projections heaters and 12 model choices of vertical projection heaters for greater versatility during heater selection. There are also multiple air discharge types to choose from. HHP2 heater capacities are supported by our sophisticated HTFSTM ACOL thermal performance analysis software. Heresite coatings are also available.

Hazloc HeatersTM General Manager, Darren Ochosky, stated, “we have expanded the model offerings on the HHP2 series to give our customers more choices for their specific applications. We are dedicated to helping our customers grow and prosper by providing leading edge industrial heating products, technical expertise, and outstanding service.” Hazloc HeatersTM is also committed to a high standard of quality and on-time delivery performance.

3 Things to Consider for Your Next Building Project

The way buildings are used — and the needs within building spaces — are continuously changing. Revitalization efforts turn abandoned warehouses into residential and commercial hot spots. Work place trends turn an old conference room into collaborative space or a wellness lounge.

Whether the changes are driven by corporate growth, new technology or shifting needs, building spaces must adjust. This is true for existing buildings and new construction.  

So how do you know what equipment and systems will meet your customers’ needs in your next building project? The answer is influenced by many factors — from upfront costs and ease of installation to integration with existing systems and flexibility for the future.

Key questions that drive next steps  

In planning your next building project, first consider a few key questions:

  • What is the budget?
  • How will the building be used and what are the operating hours?
  • What is the building size?
  • What are the energy and operational goals?
  • Will the building be managed with on-site facility staff?
  • How will results be measured?

The answers help you zero in on the right solutions and technologies to meet specific needs. A 50,000 square-foot building that is occupied 24/7 has very different needs than a 10,000 square-foot building that runs on a 9 to 5 schedule.

In choosing between the many heating, ventilation and air conditioning (HVAC) system options, consider these three factors to ensure the choice you make best meets your customers’ needs.

No. 1: Upfront costs versus long-term savings

Energy efficiency is a priority driving building design in many commercial spaces. Building owners and managers want solutions that improve efficiency, reduce costs and promote more sustainable building operation. Finding solutions that meet those needs results in more satisfied customers — making you more competitive.

Keep in mind that the most energy-efficient solution for a building may not be the option with the lowest upfront cost, just as the system with the lowest upfront cost may not be the most cost-effective long-term solution. There are trade-offs to consider when weighing these issues.

For example, are upfront cost savings so important that the building owner or manager would sacrifice long-term energy savings?

The right HVAC system is often determined by the size and usage of the building. Owners and operators of smaller commercial buildings may not have on-site facility staff, so they typically want a system that is easy to install, operate and maintain. Given these preferences, a unitary system is often a good choice for small commercial buildings.

With larger commercial buildings, there are more options to consider. Variable refrigerant flow (VRF) systems can provide affordable installation and energy efficiency over the life of the system. A chilled water system is another option in larger commercial buildings. These systems deliver high energy efficiency, but water-cooled chiller systems require ongoing water treatment and cooling tower maintenance.

Thermal energy storage can provide significant long-term cost savings by shifting a building’s energy use to off-peak hours when utility rates are lower. However, these systems are typically best suited to larger buildings because of the upfront cost and space requirements for installation.

While the project budget and priorities of the building owner are important, be sure to consider the return on investment. It’s important to look beyond upfront costs and consider the system’s long-term savings potential.

No. 2: Individual pieces versus whole building design

When specifying an HVAC solution, decisions are often made based on a single piece of equipment’s operating efficiency. But this is not the best way to achieve the most efficient building performance.

There are many variables that contribute to optimized building performance.

  • How is the building being used and occupied?
  • How do the various pieces of equipment in the building interact and work together?
  • What are the energy goals in the facility?

Instead, we must look beyond the efficiency of a single piece of equipment and consider the performance and efficiency of the entire building. Seeing the whole as greater than the sum of its parts can result in improved energy efficiency and operational cost savings for building owners and managers. And meeting customer needs with a systems-design approach can provide you with a competitive edge.

Proper energy modeling will help you evaluate equipment and determine which options will make the entire building more efficient. It allows you to optimize the systems from an energy and utility bill perspective before construction even begins — and it can pay off in improved energy efficiency and performance.

No. 3: Balancing today’s needs with future growth

Replacing or upgrading a system in an existing building requires a different approach than specifying a system for a new construction project. In existing buildings, consider what types of equipment and systems are already in place. Then look for options that can be easily integrated with existing systems and building controls. Ease of integration is also a factor when designing new buildings that are part of an existing campus or network of buildings.

Leveraging technologies already in place is one way to uncover cost savings. A hybrid VRF system, for example, can connect to existing building systems — such as a chilled water system — using integrated controls. This can result in more cost-effective expansion in some buildings.

And because building spaces are constantly changing, it’s important to consider which solutions provide the greatest flexibility for future changes. Using wireless communication technology to connect devices is one way to improve ease of integration and ensure greater flexibility for changes.

A building where equipment and systems are connected in the cloud also enables efficiency and performance. In many buildings, existing systems can be easily integrated with open protocols, such as BACnet™ or Modbus™. This includes the building automation system (BAS), which can offer cloud-based connectivity and control of building systems.

This connectivity can provide access to intelligent services that extract the operating data from building equipment and systems and use the connection into a building to run advanced analytics. This data enables facility managers to make informed decisions and take actionable steps to help ensure a building runs a peak efficiency long term — not just on day one.

Keys to success

Considering your customers’ priorities — from costs to energy efficiency to reducing ongoing maintenance requirements — can help you choose the right system for your next building project. Help deliver long-term savings and results for your customer, while positioning yourself as a valuable business partner.

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Temperature and Humidity Control for Laboratories, Medical Imaging Rooms, Libraries & Archives

By Mike Lawler, Data Aire

Whether your emphasis is on pioneering technology, developing life-saving drugs or managing the integrity of sensitive documents or artifacts, maintaining the perfect environmental envelope is vital to your success.

  • Require tight control over temperature and humidity
  • Have large swings in cooling requirement daily & annually
  • Must dehumidify when little or no cooling is required

What Type of HVAC Provides Precision Air Control for Low Load Applications?

Applications that require both temperature and humidity control must use equipment that is capable of cooling, heating, humidifying and dehumidifying modes. The most effective way to address this need is to provide one piece of equipment that provides all those modes of operation. If the load in the space is large, over 40 or 50 tons, a custom package unit can provide this function.

It can be challenging, however to find equipment in smaller tonnages that can do the job. In response to this, engineers often attempt to use Computer Room Air Conditioners (CRAC) equipment in laboratories, libraries, archives, and medical imaging rooms that have lower cooling requirements. CRAC units provide all the modes of operation needed and they are available in sizes as small at 2 tons. A deeper look into these applications, however, will show that standard CRAC units are not suited to these applications.

Standard Computer Room Air Conditioning         

  • Cooling runs more than half the time to cool the room
    Minimal moisture removal (80-90% SHR adequate) needed
    Dehumidifies <10% of running time.

Highly Variable Cooling Load Rooms

  • Zero cooling load at times
  • 60-70% SHR needed
  • May have to dehumidify half of the run hours

Design Day Reasonable Tolerances

Standard CRAC units do a good job of controlling temperature and humidity when they are required to produce cooling that is at or near their maximum capacity. Maximum cooling capacity is called for on days when the outdoor ambient temperature nears its annual maximum and, at the same time, internal heat generation from lights people, and equipment are at their maximum. This condition is known as a design day with a concurrent design load in the space. Unfortunately, these conditions only occur a few hours a year. The farther the conditions fall below the above described maximums, the more difficult it becomes to control humidity in the space to within a reasonable tolerance. When the cooling requirements fall much below 50% of maximum, the space is often subject to wide swings in temperature & humidity that are totally unacceptable to the occupants of the space.

The reason is that the standard CRAC units are not designed to remove a significant amount of humidity per hour. The dehumidification in a CRAC unit is done by the cooling coil. As long as there is a call from the thermostat to deliver cooling to the space, dehumidification happens as a byproduct of cooling down the room. When the thermostat requires that cooling be delivered for 70% or 80% of the time, the CRAC unit can keep up with the dehumidification requirements in the space. But think about how few hours per year this requirement exists in rooms that are not data rooms. Essentially, those conditions only exist in the daytime, during the hottest part of the summer.

Understanding Dehumdification and Cost Controls

Dehumidification mode, by definition, means removing humidity from the air without sending any cool air into the space. Since the cooling coil removes the moisture this means that the CRAC unit must run the cooling and the heating in the unit at the same time.

There are two problems with this. First there is only ½ as much heat capacity in a standard CRAC unit as there is cooling capacity. That means the already minimal amount of dehumidification available at full load is cut in ½. You cannot increase the cooling capacity to get more dehumidification. If you do, there is not enough heat in the unit to offset the increased cooling capacity. Cold air would be delivered to the space and the space temperature will begin to drop too low. Unless it is hot outside and there is a significant requirement for cooling from the space a standard CRAC units simply cannot reach the desired humidity setpoint.

The second problem is that heat in CRAC units is provided by electric resistance heating elements. From a power cost standpoint, this is absolutely the most expensive source of heat anyone can use. In a data room the electric heat runs only a handful of hours a year so this is not an issue. In other applications though, the electric heat runs hundreds or even thousands of hours per year while in the dehumidification mode.

These problems are particularly acute in laboratories, archives, libraries, clean rooms, dry storage and other applications that require that humidity be controlled in the absence of a need for cooling.

Small clean rooms are usually rooms surrounded by a space that already has temperature, but not humidity control. Like an archive, there is very little need to cool the space and the primary mode of operation is dehumidification. Laboratories, libraries, museums, MRI suites, CT scan rooms, art vaults and many other applications face the same challenge, dehumidification is needed more than cooling is needed.

Interpret the Temperature and Humidity Needs of Your Space with an All-In-One HVAC

Data Aire has solved these challenges by introducing InterpretAireTM, a packaged cooling, heating, humidifying, and dehumidifying unit that has all of the advantages of a standard CRAC unit and none of the drawbacks. The thing that sets InterpretAireTM apart from the competition is its ability to dehumidify when there is no need for cooling. Humidifying is relatively straightforward and easy for a standard CRAC to accomplish. Precise temperature control is not that difficult in most applications either. There are multiple strategies that standard CRAC units can use to deliver good temperature control. None of those strategies allow the CRAC unit to deliver better dehumidification control.

The Data Aire InterpretAire climate management system can be programmed to maintain constant temperature and humidity within a laboratory, clean room, museum, library or archive to ensure a desired outcome. Consistency and precision were key drivers in the development of the InterpretAire solution. InterpretAire quite literally interprets the needs of the space, and maintains the unique temperature and humidity perimeters mandated for high-accuracy standards.

Your application needs are specific; your environmental control equipment should be, too.

 

Q&A:  New Generation of Alternative Refrigerants

What concerns are there about HFCs?

With growing concerns about the impact on the environment and climate change, pressure has been mounting for years to reduce the use of high-GWP refrigerants across many applications and industries.

One of the reasons HFCs are under pressure is because they have longer atmospheric lives. For example, R-134a survives 14 years compared to R-1233zd(E), one of the new alternative refrigerants, at only 29 days. All chemicals have a finite life, but some are more stable than others. In general, the shorter the atmospheric life, the lower the environmental impact because the chemical does not endure long in the atmosphere and have an impact.

Today, the next-generation refrigerants are more expensive than the current refrigerants in the marketplace.  If we look at the history of past refrigerant transitions, we can expect the current generation HFCs to begin to become more expensive in the coming years, and the new HFO refrigerants to come down in price as more factories are built and use spreads to more industries.  This pricing shift in refrigerants could push the transition to next generation solutions ahead of current mandated phase out dates.

What actions have been taken to phase down HFCs? (i.e., SNAP, Kigali Agreement) What is the timeline?

On October 15, 2016, the Kigali Amendment to the Montreal Protocol was signed, paving the way for the global phase-down of HFCs. All 197 member countries, including the United States and Canada, agreed last year to amend the Montreal Protocol (an international treaty originally designed to reduce the production and consumption of ozone-depleting substances) to phase down HFCs.

Ahead of the Kigali Amendment, the U.S. Environmental Protection Agency (EPA) issued two rules regarding the change of listing status of certain HFCs in the United States. The first rule established phase-out dates for HFCs in retail food refrigeration, aerosol propellants and motor vehicles. The EPA used its regulatory authority through the Significant New Alternatives Policy (SNAP) by designating particular HFC refrigerants as “unacceptable” and disallowing their use in aerosol propellants starting in 2016, new retail food refrigeration starting in 2017, and motor vehicles with model year 2021. The second EPA rule established the phase-out date for certain HFCs in chillers. Specifically, R-134a, R-410A and R-407C are banned from use in new chillers (air-cooled and water-cooled, scroll, screw and centrifugal) beginning January 1, 2024.

In a separate rule, the EPA also made several other changes to management requirements for refrigerants in Section 608 of the Clean Air Act, entirely in effect by January 1, 2019, to include the following:

  • Extending the requirements previously in place for only ozone depleting substances, such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) to include all replacement substances, including HFCs and the new hydrofluoroolefin (HFO) options. Hydrocarbons in small, self-contained systems are given an exception for venting.
  • Reduced trigger leak rates for a 12-month period (for example, from 15% to 10% for comfort cooling equipment), which require owners or operators to take corrective action. This may push or incentivize the industry to move to technologies that are more hermetic with fewer joints and seals, for better long-term refrigerant containment.
  • New requirements for mandatory leak inspections on equipment and increased record keeping requirements.

Are alternative refrigerants available?

New refrigerant technology is developing rapidly and alternative refrigerants are starting to emerge as potential next-generation solutions. These choices are nonflammable solutions. The two low pressure options feature ultra-low GWPs, one of which has operating pressures similar to R-123, that are ideal for chiller applications with larger refrigerant charge sizes. There is also a nonflammable alternative to R-134a, which has a significantly reduced GWP.

These alternative refrigerants are characterized by very short atmospheric lives (measured in months or even days, which results in refrigerants with “effectively zero” ODP and low GWPs.  This new class of refrigerants is collectively referred to as hydrofluoroolefins (HFOs) and includes new options such as R-1233zd(E), R-1234yf, R-1234ze(E), R-1336mzz(Z), R-513A, R-514A, R-452B and R-454B).

What are the main ones for commercial and institutional HVAC equipment?

The low–global warming potential refrigerants that are primarily being used for commercial and institutional HVAC equipment are: R-514A and R-1233zd(E) — both featuring an ultra-low GWP of less than 2, and R-513A, a next-generation, low-GWP refrigerant. R-513A provides an excellent performance to R-134a, with a 56 percent reduction in GWP.

Is equipment that uses the alternatives available now?

Yes, there are equipment options already available on the market that can use these alternative refrigerants. Trane® is already offering customers options to reduce greenhouse gas emissions in their facilities through the use of next generation refrigerants in HVAC products. Trane plans to transition their current portfolio of HVAC products that use refrigerants to be compatible with next generation refrigerants well before phase-out dates to offer customers choices without compromising safety, reliability and efficiency.

We have expanded our chiller portfolio significantly in the last 18 months to address the increasing customer demand for climate-friendly systems. Our promise to customers has always been to deliver right product with the right refrigerant at the right time, ensuring that products meet all regulatory requirements.

The EcoWise™ portfolio was created by Ingersoll Rand® as part of our company’s Climate Commitment to reduce greenhouse gas emissions from its products and operations by 2030. Trane products within the EcoWise portfolio meet the following requirements:

      • Are available with next-generation, lower-GWP refrigerants
      • Reduce greenhouse gas (GHG) emissions
      • Maintain safety and energy efficiency through innovative design
      • Meet or exceed emissions regulations

The following products have earned the EcoWise endorsement:

Trane® CenTraVac™ centrifugal chillers for large buildings and industrial applications can operate with either R-123 or next-generation refrigerants R-514A or R-1233zd(E) — both featuring an ultra-low GWP of less than 2.  

Trane Series S™ CenTraVac chillers deliver the highest full and part-load efficiencies on the market today, offering customers a choice of either R-123 or the next generation refrigerant R-514A that has an ultra-low GWP of less than two.

Trane Series R® RTWD water-cooled chiller and Trane Sintesis™ air-cooled chillers can operate with a choice of R-134a or Opteon™ XP10 (R-513A), a next-generation, low-GWP refrigerant.

Is the industry expecting any disruptions?

As standards and codes continue to change, there are many factors to consider as the industry works to find the best balance between minimizing environmental impacts, maintaining safety, and managing product costs.

The HVACR industry will likely have to adjust product refrigerant charge sizes in most direct expansion applications to meet the standards. The establishment of the new 2L sub-classification for refrigerant flammability addresses new next-generation refrigerants that have lower flammability characteristics. The HVACR industry is actively investigating the safety of flammable refrigerants for indoor and outdoor use, and determining the risks of flammable refrigerants by understanding the probability of potential occurrences and severity of events in various application situations including servicing and handling. Some direct refrigerant expansion applications where refrigerant charge sizes are quite large, such as large splits, VRF systems, and large distributed commercial refrigeration systems, may not be available in their current form in the future because of flammability requirements.

The HVAC industry has worked very closely with the US EPA to ensure that the phase down timelines allow an appropriate amount of time for manufacturers to develop product with next generation solutions.  Ingersoll Rand® intends to have products available in all market segments with next generation solutions ahead of the required transition dates.

Are there tradeoffs with the new refrigerants?

Refrigerant selection is a balancing act. While the HVACR industry evaluates next-generation refrigerant alternatives, the challenge is to balance environmental benefits with safety, sustainability and design requirements. It’s likely that tradeoffs between GWP, flammability and efficiency will be needed to be made in selecting refrigerants.

When considering refrigerant alternatives for the future, policy makers, the public and manufacturers must select refrigerants with the best balance of the following:

  • Environmental performance (direct environmental impact such as reduced GWP)
  • Safety for consumers (flammability and toxicity)
  • Energy efficiency (indirect environmental impacts such as reduced CO2 emissions)
  • Intellectual property considerations
  • Transition costs (impact on industry and consumers)
  • Product sustainability (long operational life, reliability, maximizing recyclable content and repurposing components)

One of the most important environmental impacts to consider when transitioning to new refrigerants is energy efficiency.  We believe that there will be a great opportunity for the industry to improve energy efficiency with next-generation solutions.  R-410A replacements are currently being developed which could see significant efficiency improvements. For large tonnage centrifugal chillers, we are seeing the industry looking toward more efficient low pressure solutions (like R-514A and R-1233zd(E)) that are better in efficiency than medium pressure R-134a.

U.S. Environmental Protection Agency, 2015, Federal Register, Vol.80, No.138, p.42870-42959.

U.S. Environmental Protection Agency, 2016, Federal Register, Vol.81, No.231, p.86778-86895.

U.S. Environmental Protection Agency, 2016, Federal Register, Vol.81, No.223, p.82272-82395.

Improving Indoor Air Quality

By: United Cool Air

Most air conditioners recirculate indoor air. While this saves energy, there is a very serious health cost to pay when people breathe indoor air instead of outdoor air! According to the United States Environmental Protection Agency (EPA), indoor air is two to five times MORE TOXIC on average than outside air. This is true even in the most heavily polluted United States metropolitan areas! In fact, some inside air has been found to be as much as one hundred times more toxic than the outside air in metropolitan areas!

Why Is the Inside Air So Toxic?

It’s a combination of a great many factors, some of which we’ll discuss below. For now, just know that the toxins found in inside air are mostly all human made and are more heavily concentrated during seasons when we don’t open windows, such as the warmer seasons when we run air conditioning. Furthermore, newer buildings that are “better insulated” tend to have inside air that is more toxic than older “drafty” buildings.

Toxins that Diffuse Out of Common Indoor Items

Many buildings have carpet and furniture. The foam on the back of the carpet and in the stuffing of the furniture provides a constant source of volatile organic chemicals (VOCs), which are known carcinogens and irritants. These VOCs are found in many other indoor items too such as drapes and shower curtains. You know that funky “new odor” you smell when you hang the new shower curtain? That’s VOCs leaching out. They continue to leach out into the air even when you don’t smell them any more so your nose is not the best guide when it comes to toxins in inside air.

We Bring Other Nasty Chemicals Indoors That Contaminate Our Air

We use pesticides that emit toxins into the air we breathe. Popular industrial cleaners contain toxic chemicals like phthalates, erchloroethylene or “PERC), triclosan, ammonia, chlorine, and 2-Butoxyethanol. There’s paradicholorbenzene in mothballs. Flame-retardants found in mattresses, clothes, electronics, and are composed of polybrominated diphenyl and ethers–PBDEs, both highly toxic! These same nasty chemicals plus PCBs (phthalates) are found in many plastic products, including toys, plastic plant pots, food containers, lamps, picture frames, eyeglass frames, and plastic organizers. Particleboard furniture emits formaldehyde for as long as you have it in your space!

Does your carpet, furniture, clothes, or other products state they are “stain resistant?” Does your cookware say “non stick?” If so, these items contain perfluorinated acids (PFAs), which cause birth defects! Then there are all the nasty chemicals in our building supplies such as the methylene diphenyl diisocyanate found in spray foam insulation and the resins found in paint, varnishes, and tiles! There’s also radon gas from your flooring and toxins released from mold!

What Are Health Costs?

We’ve already mentioned cancer and birth defects but there are other health hazards that are also caused by toxic indoor air as well. For example, scientists now believe that toxic indoor air may be partially responsible for the soaring rates of autism and Asperger’s in children! It can also cause nervous conditions like ADD and general anxiety. Heart diseases has been linked to the many of the nasty chemicals found in toxic indoor air too. Asthma and allergies that have been on the rise are thought to be linked to toxic indoor air. In fact, many chronic illnesses are linked to or exacerbated by toxic indoor air. These include sinus issues, skin rashes, dizziness, runny nose, persistent cough, achy joints, digestive issues, irritated eyes, nausea, poor concentration, memory loss, weakened immune system, and general fatigue.

OmegaAir and Alpha Aire — DOAS That Pull 100% OUTDOOR Air

When it’s hot and or humid outside, it can be just miserable if you don’t run your air conditioner! However, since most air conditioners recirculate toxic inside air, it can be a difficult choice on what to do. Do you open your windows and just try to bear the hot sticky feel? Or do you close your windows and feel comfortable while knowing you’re breathing in all that toxic air?

The Alpha Aire and Omega Air 100% outdoor air systems like all UCA air conditioning equipment are designed for indoor installation! Air handlers and condensers require no exterior mounting space, which is critical in multi-floor, urban applications. Indoor unit mounting preserves the architectural integrity of the building by keeping the roof and perimeter free of obstructions. In addition to eliminating the roof loads, the installation and maintenance costs are lower, the equipment is protected from the elements and security is enhanced because of limited outdoor access.