GreenField Direct LLC
800-246-5325
www.greenfielddirect.com
eProduct 185
Thảm Cho Trẻ, Thảm Cho Bé, Thảm Lót Nhà Trẻ là một trong những sản phẩm chính của chúng tôi, nhằm giúp cho bé hạn chế té ngã và chấn thương
GreenField Direct LLC
800-246-5325
www.greenfielddirect.com
eProduct 185
GreenField Direct LLC
800-246-5325
www.greenfielddirect.com
eProduct 185
GreenField Direct LLC
800-246-5325
www.greenfielddirect.com
eProduct 185
GreenField Direct LLC
800-246-5325
www.greenfielddirect.com
eProduct 185
That’s why it annually invites trade press from the six disciplines it focuses on — plumbers, electricians, HVAC technicians, builders, remodelers, and maintenance personnel — for a day-long rollout of the latest power tools and accessories.
This year’s event drew 77 media members from seven countries. President Steve Richman said the new product rollout was designed to “outpace competitors” while at the same time “outperforming and outthinking.” He said this has resulted in a 35 percent growth in the business over the previous year.
Here is a sampling of some of the latest products that have applications for the HVACR sector.
• Jackets: For technicians on rooftops in cold weather climates the company showed an expanded line of M12™ heated gear with the introduction of new warming features, accessories, and jacket colors. A new fleece inner liner and heating elements are now in the chest and upper back, and lower pockets that are controlled independently of the core heating elements, with the latter added to provide extra warmth to the hands. Each heating element is composed of sewn in carbon fiber heating zones that can be set to high, medium, or low with a touch of a button on the lapel. An upgraded battery holder now includes a battery fuel gauge and a USB port for charging portable electronic devices. The M12™ Red Lithium™ battery delivers up to six hours of continuous heat on a single battery charge, the company said.
Related to that, the company also introduced the Heated Jacket 12v DC plug adapter which utilizes a 7-foot coil cord for cord routing throughout a vehicle.
• Copper Press Tool: For copper and steel pipe press connections, the company introduced the ForceLogic™ press tool line. Featuring a one-handed, in-line design, the new press tool allows for navigating around installed pipes.
Utilizing Redlink™ electronics, the tools monitor the force output and visually indicate both a secure connection and when the tool needs calibration, the company said. “In today’s turbulent market, mechanical contractors must look to time and cost saving solutions to deliver significant productivity and profitability enhancements,” said Corey Dickert, senior product manager. “The new ForceLogic™ Press Tools take that mentality to the next level.”
• Caulk and Adhesive Gun: The company introduced the M12™ cordless caulk and adhesive gun. Said David Lincoln, product manager, “The M12™ caulk and adhesive gun is a lightweight, compact, and affordable solution that allows users to eliminate the excessive fatigue they experience by using repetitive manual tools all day. This new tool is optimized for use with common construction sealants and adhesives.”
• Thermal Imager: The 160x120 thermal imager is for preventative maintenance and troubleshooting applications. It features 160 by 120 pixel, high resolution thermal images, a visual camera for standard pictures, and a wide temperature range.
“Designed from the ground up with the professional tradesman in mind, this tool is fast, versatile, and easy to use,” said Jon Morrow, director of marketing, test and measurement. “Users are able to capture a thermal and visual image on every trigger pull and toggle between the two with the push of a button. With a five-button interface and a no blur, no-wait display that updates the screen image 60 times a second, this tool is easy to use and delivers professional quality.”
For more information, go to www.milwaukeetool.com.
Publication date: 7/30/2012
That’s why it annually invites trade press from the six disciplines it focuses on — plumbers, electricians, HVAC technicians, builders, remodelers, and maintenance personnel — for a day-long rollout of the latest power tools and accessories.
This year’s event drew 77 media members from seven countries. President Steve Richman said the new product rollout was designed to “outpace competitors” while at the same time “outperforming and outthinking.” He said this has resulted in a 35 percent growth in the business over the previous year.
Here is a sampling of some of the latest products that have applications for the HVACR sector.
• Jackets: For technicians on rooftops in cold weather climates the company showed an expanded line of M12™ heated gear with the introduction of new warming features, accessories, and jacket colors. A new fleece inner liner and heating elements are now in the chest and upper back, and lower pockets that are controlled independently of the core heating elements, with the latter added to provide extra warmth to the hands. Each heating element is composed of sewn in carbon fiber heating zones that can be set to high, medium, or low with a touch of a button on the lapel. An upgraded battery holder now includes a battery fuel gauge and a USB port for charging portable electronic devices. The M12™ Red Lithium™ battery delivers up to six hours of continuous heat on a single battery charge, the company said.
Related to that, the company also introduced the Heated Jacket 12v DC plug adapter which utilizes a 7-foot coil cord for cord routing throughout a vehicle.
• Copper Press Tool: For copper and steel pipe press connections, the company introduced the ForceLogic™ press tool line. Featuring a one-handed, in-line design, the new press tool allows for navigating around installed pipes.
Utilizing Redlink™ electronics, the tools monitor the force output and visually indicate both a secure connection and when the tool needs calibration, the company said. “In today’s turbulent market, mechanical contractors must look to time and cost saving solutions to deliver significant productivity and profitability enhancements,” said Corey Dickert, senior product manager. “The new ForceLogic™ Press Tools take that mentality to the next level.”
• Caulk and Adhesive Gun: The company introduced the M12™ cordless caulk and adhesive gun. Said David Lincoln, product manager, “The M12™ caulk and adhesive gun is a lightweight, compact, and affordable solution that allows users to eliminate the excessive fatigue they experience by using repetitive manual tools all day. This new tool is optimized for use with common construction sealants and adhesives.”
• Thermal Imager: The 160x120 thermal imager is for preventative maintenance and troubleshooting applications. It features 160 by 120 pixel, high resolution thermal images, a visual camera for standard pictures, and a wide temperature range.
“Designed from the ground up with the professional tradesman in mind, this tool is fast, versatile, and easy to use,” said Jon Morrow, director of marketing, test and measurement. “Users are able to capture a thermal and visual image on every trigger pull and toggle between the two with the push of a button. With a five-button interface and a no blur, no-wait display that updates the screen image 60 times a second, this tool is easy to use and delivers professional quality.”
For more information, go to www.milwaukeetool.com.
Publication date: 7/30/2012
GreenField Direct LLC
800-246-5325
www.greenfielddirect.com
eProduct 185
GreenField Direct LLC
800-246-5325
www.greenfielddirect.com
eProduct 185
Tool Programs
Many of the tool programs HVAC contractors make available seem to have a common thread — they want to make it easy for technicians to have access to quality tools. Comfort Matter Heating and Cooling (Hanover, Minn.) provides tools for its technicians. The company will replace any tools returned broken but if the technicians lose a tool, they are required to replace it. Empire Heating and Air’s (Decatur, Ga.) policy is similar. The contractor provides some tools for its technicians, especially the more expensive ones. The rest are employee owned, but if the employee-owned tool is broken during the course of proper use, the company will replace it as long as the technician turns in the broken tool.
Tool programs extend beyond providing and replacing technicians’ tools. Kahn Mechanical Contractors (Dallas) doesn’t provide tools for its contractors, but it does have a program to help technicians acquire the appropriate tools.
“With approval of a supervisor, a technician can purchase tools at any supply house,” explained Ann Kahn, president of Kahn Mechanical Contractors. “The technician is required to sign an agreement that the cost of the tool, plus the sales tax, will be deducted from his pay at a set schedule.”
Travis Smith is the general manager at Sky Heating and Air Conditioning (Portland, Ore.), and the company he works for has taken its tool program high tech. It provides more expensive, digital tools that aren’t used more than once a month or so and leaves the standard hand tools and a set of refrigerant gauges up to the technician.
“If our technicians want to invest in their futures and purchase more tools, we provide a tool account that deducts $50 per paycheck from what they owe for tools purchased,” said Smith.
Another viable tool program is offered at Samm’s Heating and Air conditioning (Plano, Texas). Paul Sammataro, president of the company, has employed a tool match program that he is pleased with.
“Every December we allow our techs to purchase tools at our suppliers, which we will match up to $250 maximum spent,” he explained. “We then deduct the techs’ totals in eight equal payments from their checks, starting in January.”
Truck Care Policies
There are plenty of variations of tool policies when talking to different contractors, but many of them seem to agree that taking care of the truck is the technician’s job. Fred Kobie, president of Kobie Kooling (Fort Myers, Fla.), considers the truck to be the technician’s office.
“Each technician is responsible to clean the vehicle, and the vehicles are inspected routinely. The maintenance schedule is also planned by the technician with our service company for oil changes, tire rotation, etc.,” he explained. “All of the technicians are allowed to take the vehicle to our servicer for a concern at any time and also to make repairs in the field as they see fit. This is their office, and we encourage them to keep it clean and working well.”
To help his technicians keep their vehicles clean, Corey Hickman, president of Comfort Matters Heating and Cooling, provides them with a pass key for a local carwash. In his company, it is the technician’s responsibility to keep the service truck clean and organized.
Martin Hoover takes his clean truck policy one step further. As president of Empire Heating and Air (Decatur, Ga.), he requires that his employees keep the trucks clean and stocked or run the risk of losing company truck privileges.
“If the truck is not clean and properly stocked, technicians may lose their truck privileges and would then have to drive a personal vehicle to and from the shop,” he said.
GPS Installation?
Tool programs can be a morale booster, truck policies are usually expected, but where contractors and technicians often differ is GPS installation. Benefits to the business include efficient dispatching, quick contact with technician, onboard directions to calls, maintenance notifications, simple time card preparation, and call verification for customers.
For Dennis Purvis, service manager for Mechanical Services Inc. of Central Florida in Orlando, GPS has not only helped with customers, but it also helped him whittle out undesirable behavior from some of the employees he manages.
“Installing GPS forced the dishonest techs to leave,” he said. “GPS works wonderfully when clients question how long a tech has been on site. I can show an actual report of when the tech was on site and for how long.”
Despite some of the positive consequences of a GPS system, Kobie has decided that this approach is not for his company. Kobie Kooling was what he described as a “pioneer with tracking systems years ago.” After his endeavor with the systems, Kobie found that following the vehicles and the expense as opposed to offering rewards was not feasible or truly beneficial.
“We allow some flexibility with the schedule so a technician can stop at a store or be involved at home without worrying who is watching on GPS,” he explained. “There has been very little abuse, and I have found the added trust factor pays dividends as to how technicians take care of our vehicles.”
Sidebar: What’s in Your Tool Bag?
The NEWS asked a group of HVAC professionals what they thought the top five tools every technician should have were. The following is a list of the top five most popular answers we received, in no particular order.
• Digital multimeter
• Refrigerant gauges
• 5+1 screwdriver
• Vacuum pump
• Manometer
What are your top five tools? Head to www.facebook.com/achrnews and post them on The NEWS page.
Publication date: 11/5/2012
That’s why it annually invites trade press from the six disciplines it focuses on — plumbers, electricians, HVAC technicians, builders, remodelers, and maintenance personnel — for a day-long rollout of the latest power tools and accessories.
This year’s event drew 77 media members from seven countries. President Steve Richman said the new product rollout was designed to “outpace competitors” while at the same time “outperforming and outthinking.” He said this has resulted in a 35 percent growth in the business over the previous year.
Here is a sampling of some of the latest products that have applications for the HVACR sector.
• Jackets: For technicians on rooftops in cold weather climates the company showed an expanded line of M12™ heated gear with the introduction of new warming features, accessories, and jacket colors. A new fleece inner liner and heating elements are now in the chest and upper back, and lower pockets that are controlled independently of the core heating elements, with the latter added to provide extra warmth to the hands. Each heating element is composed of sewn in carbon fiber heating zones that can be set to high, medium, or low with a touch of a button on the lapel. An upgraded battery holder now includes a battery fuel gauge and a USB port for charging portable electronic devices. The M12™ Red Lithium™ battery delivers up to six hours of continuous heat on a single battery charge, the company said.
Related to that, the company also introduced the Heated Jacket 12v DC plug adapter which utilizes a 7-foot coil cord for cord routing throughout a vehicle.
• Copper Press Tool: For copper and steel pipe press connections, the company introduced the ForceLogic™ press tool line. Featuring a one-handed, in-line design, the new press tool allows for navigating around installed pipes.
Utilizing Redlink™ electronics, the tools monitor the force output and visually indicate both a secure connection and when the tool needs calibration, the company said. “In today’s turbulent market, mechanical contractors must look to time and cost saving solutions to deliver significant productivity and profitability enhancements,” said Corey Dickert, senior product manager. “The new ForceLogic™ Press Tools take that mentality to the next level.”
• Caulk and Adhesive Gun: The company introduced the M12™ cordless caulk and adhesive gun. Said David Lincoln, product manager, “The M12™ caulk and adhesive gun is a lightweight, compact, and affordable solution that allows users to eliminate the excessive fatigue they experience by using repetitive manual tools all day. This new tool is optimized for use with common construction sealants and adhesives.”
• Thermal Imager: The 160x120 thermal imager is for preventative maintenance and troubleshooting applications. It features 160 by 120 pixel, high resolution thermal images, a visual camera for standard pictures, and a wide temperature range.
“Designed from the ground up with the professional tradesman in mind, this tool is fast, versatile, and easy to use,” said Jon Morrow, director of marketing, test and measurement. “Users are able to capture a thermal and visual image on every trigger pull and toggle between the two with the push of a button. With a five-button interface and a no blur, no-wait display that updates the screen image 60 times a second, this tool is easy to use and delivers professional quality.”
For more information, go to www.milwaukeetool.com.
Publication date: 7/30/2012
That’s why it annually invites trade press from the six disciplines it focuses on — plumbers, electricians, HVAC technicians, builders, remodelers, and maintenance personnel — for a day-long rollout of the latest power tools and accessories.
This year’s event drew 77 media members from seven countries. President Steve Richman said the new product rollout was designed to “outpace competitors” while at the same time “outperforming and outthinking.” He said this has resulted in a 35 percent growth in the business over the previous year.
Here is a sampling of some of the latest products that have applications for the HVACR sector.
• Jackets: For technicians on rooftops in cold weather climates the company showed an expanded line of M12™ heated gear with the introduction of new warming features, accessories, and jacket colors. A new fleece inner liner and heating elements are now in the chest and upper back, and lower pockets that are controlled independently of the core heating elements, with the latter added to provide extra warmth to the hands. Each heating element is composed of sewn in carbon fiber heating zones that can be set to high, medium, or low with a touch of a button on the lapel. An upgraded battery holder now includes a battery fuel gauge and a USB port for charging portable electronic devices. The M12™ Red Lithium™ battery delivers up to six hours of continuous heat on a single battery charge, the company said.
Related to that, the company also introduced the Heated Jacket 12v DC plug adapter which utilizes a 7-foot coil cord for cord routing throughout a vehicle.
• Copper Press Tool: For copper and steel pipe press connections, the company introduced the ForceLogic™ press tool line. Featuring a one-handed, in-line design, the new press tool allows for navigating around installed pipes.
Utilizing Redlink™ electronics, the tools monitor the force output and visually indicate both a secure connection and when the tool needs calibration, the company said. “In today’s turbulent market, mechanical contractors must look to time and cost saving solutions to deliver significant productivity and profitability enhancements,” said Corey Dickert, senior product manager. “The new ForceLogic™ Press Tools take that mentality to the next level.”
• Caulk and Adhesive Gun: The company introduced the M12™ cordless caulk and adhesive gun. Said David Lincoln, product manager, “The M12™ caulk and adhesive gun is a lightweight, compact, and affordable solution that allows users to eliminate the excessive fatigue they experience by using repetitive manual tools all day. This new tool is optimized for use with common construction sealants and adhesives.”
• Thermal Imager: The 160x120 thermal imager is for preventative maintenance and troubleshooting applications. It features 160 by 120 pixel, high resolution thermal images, a visual camera for standard pictures, and a wide temperature range.
“Designed from the ground up with the professional tradesman in mind, this tool is fast, versatile, and easy to use,” said Jon Morrow, director of marketing, test and measurement. “Users are able to capture a thermal and visual image on every trigger pull and toggle between the two with the push of a button. With a five-button interface and a no blur, no-wait display that updates the screen image 60 times a second, this tool is easy to use and delivers professional quality.”
For more information, go to www.milwaukeetool.com.
Publication date: 7/30/2012
SUPCO
732-223-6644
info@supco.com
http://www.supco.com/
eProduct 186
Lucas-Milhaupt Inc.
800-521-5490
www.silfos.com
eProduct 183
Commissioning agents make sure it really does happen that way. From fixing glitches and tuning existing HVAC systems to providing new systems that deliver the promised results, building commissioning agents are focused on performance.
Geremy Wolff and his team of HVAC experts know what’s at stake. Wolff manages the commissioning team for McKinstry, a Seattle design-build and service firm that specializes in mechanical systems and green building technology.
It’s their job to prove that the state-of-the-art mechanical systems McKinstry has designed are delivering the energy-efficient performance owners and tenants expect. In existing facilities, they do retrocommissioning or building optimization to diagnose and fix problems in system operations and performance.
Commissioning Verifies Performance
“Our commissioning group was born as a support mechanism for our design-build construction group,” Wolff said. “We want to ensure that what we intended when we sold it to the customer is what they got at the end of the project. We’re responsible for bringing the equipment online and testing it to make sure it meets the performance standards that we set forth.”
Wolff’s 20-member commissioning team brings together a wide range of skills in engineering and multiple trades. Plus, the team can draw on the experience of the entire 1,600-person McKinstry organization, where collaboration is the standard. “We interface with all the different groups within the company to get all the right people in the room and make sure we’re making good decisions,” Wolff said. The commissioning group serves in-house customers — design-build, energy services, or maintenance — and provides third-party commissioning and building tuneup services to outside customers.
“We do a lot of work directly for customers, or partnering with utilities,” Wolff said. “Sometimes their system performance has degraded over time, and they just want someone to push the reset button for them. Their energy spend has been going up and they don’t know why. HVAC is a significant chunk of your energy spend in a building — typically 30 percent of total utility costs — so there’s a good return in having someone come in and do a multipart project to determine where’s the energy going and come out with some modifications.” The goal for such improvements is typically a two-year payback.
Retrocommissioning/Tuneup Process
Retrocommissioning follows the scope, investigate, and verify process.
Scoping Phase — This phase comes first. The team spends several days reviewing design drawings and utility usage, walking the facility with the building engineer, learning the ins and outs of its operation and sampling such performance factors as temperature, CO2 level, and airflow. “We’ll do lots of spot measurements, sensor calibration verification, and data logging,” Wolff said.
Additional advances in building automation systems allow many buildings to be monitored remotely over the Internet. “We’ll look at temperature, look at scheduling, and set up a trend log to record, say, the temperature coming out of an air handler every ten minutes,” he said. “We’re able to download that information, plot it on a chart, and compare it to outside air, looking at the damper positions, looking at the heating and cooling load in the building, and try to figure if it is performing optimally.”
Investigation Phase — This phase comes next. “The investigation phase will reveal lots of things they need to do to the building,” said Wolff. The team studies building operations in detail and calculates the payback period for a laundry list of changes. Many are simple: adjusting dampers and returning thermostat and timer settings (which are frequently reset by tenants) to their most economical settings. Other improvements, like replacing an aging chiller unit, are capital improvements with a longer payback. By comparing the performance improvements possible in both cost savings and comfort, the building owner can decide which changes make the most sense.
In the Implementation Phase, the team carries out the measures the building owner has selected. “We’ll go through the list and have them decide which of these projects they want to implement,” Wolff said. “A lot of times we’ll have them set aside a certain amount of money at the start of the project, and we’ll help them figure out what is the best use of that money.”
Performance Verification — This is the final commissioning step. “For anything we’ve identified as an issue and had somebody fix, we want to have our team go back in and verify that the issue was resolved and our goals were met,” Wolff said. “We could do anything from a simple test to a long-term measurement and verification process, where we’ll actually monitor the utility data for them over a period of time.”
The process involves a wide variety of checks and tests. Was the right equipment installed according to specs, manufacturer requirements, and best practices? Does it perform correctly on start-up, in terms of current draw, voltage, temperature, pressure, and flow? Are controls and sensors calibrated accurately? Does the equipment work well both as a stand-alone and in working with other parts of the system? And finally, do emergency backup systems, such as power supplies and generators, perform as expected?
The Importance of Accuracy
Whether they’re squeezing energy consumption out of an existing HVAC system or fine-tuning a brand-new McKinstry-designed setup, Wolff’s team bases its credibility on accurate test tools that produce dependable test results.
“For us, accuracy is really important,” he said. “We’re typically verifying somebody else’s work. Our devices have to be more accurate than what we’re measuring. Every one of my guys carries in their tool bag a Fluke 87V digital multimeter, a clamp meter for measuring current, and a Fluke 50 Series II thermometer — those are troubleshooting and testing tools that we always have. We’re always measuring voltage and amperage.
“We have the Fluke 975 AirMeter™ testers that we use for measuring CO and CO2. If we’re doing demand ventilation control in a building, we can use the 975 to measure CO2 levels, or for our parking garage we can measure CO levels. When our sustainability group is certifying a building as Energy Star®, the walkthrough involves verifying what temperature and ventilation rate is maintained and so on. We use the 975 to take CO2 and temperature measurements on the fly during the walkthrough.”
They use the Fluke 922 airflow meter/micromanometer to supplement larger and more cumbersome testers to measure airflow and pressure. And when utilities want verification as to how much energy a project has saved, the Fluke 43B power quality meter handles the job.
Building a High-Tech Renaissance
A building renovation now under way near Seattle shows the key role commissioning plays in a major project. There, construction crews are retrofitting an empty factory where workers in “bunny suits” once worked in clean rooms making semiconductors. The old factory opened in 1983 and passed through a series of owners.
A new chapter began in 2007, when Northwest real estate developer Benaroya Companies committed to a major investment on the 92-acre property, and its 700,000 square feet of buildings that had sat empty for 10 years. Today what’s called the South Hill Business + Technology Park is crowded with construction vehicles as workers ready the old factory for use as a data center to house the servers that hold corporate data and drive the Internet.
Energy Usage Can Make or Break a Deal
McKinstry was assigned to design and build mechanical systems capable of turning the old semiconductor factory into a world-class data center. It’s a major transformation, and provable energy efficiency is the key to success.
“Data center energy usage is a huge factor” for tenants or buyers, said Mark Johnson, head of construction for Benaroya. “It can make or break a deal. It’s measured by PUE (power usage effectiveness) — total usage divided by server usage. The savings can be in the millions.”
The sound building structure, good network access, and ample power supply gave McKinstry a solid starting point. But when it comes to HVAC system design, clean rooms and data centers share little in common. Out went the clean room’s HEPA filters, replaced by an HVAC system engineered to cool banks of data servers at the lowest possible cost.
The finished data center space is bright, spotless, and vast. The room stretches 180 feet by 130 feet, unobstructed by walls or columns. McKinstry’s design uses the latest approach to data center cooling: separate hot and cold aisles for the data equipment, together with total reliance on outside air for cooling (see sidebar).
The innovative cooling systems in this facility represent the next generation data center. The extremely low PUE and power rates will provide very low operating costs compared to a typical data center. With these innovations, South Hill will be awarded LEED certification.
But first, Wolff’s team must demonstrate that the HVAC system can handle the heat load of a data center (as measured in watts per square foot) before the data center is in place. Wolff’s team may temporarily install electric heaters in the data center space to duplicate the heat that banks of computer equipment will create. That’s on top of their usual commissioning task load of installation verification; equipment startup operational test; confirm equipment controls sensors for temperature, pressure, and flow; and an integrated system test.
An Expert on Everything
“One of the challenges with commissioning is they expect you to be an expert on everything,” Wolff said. “One of the advantages we bring is the depth and breadth of resources we have at McKinstry. If we have a problem with a boiler, I can go to my speed dial and talk to an engineer who designs these systems, talk to a pipe-fitter who pipes them, an electrician or a service tech who’s been out fixing these things for the last 20 years. We leverage all the different resources we have to make sure we’re providing the customer the best input and feedback.
“We’re not the type of company that’s trying to sell just one solution set to somebody,” Wolff said. “It’s really trying to understand what are your needs, and what do we have that can help you with your needs.”
Sidebar: Center Cools Economically
The latest approach to data center cooling uses separate hot and cold aisles for the data equipment. Equipment runs at higher temperatures than in the past. The cool, low-humidity Northwest climate allows total reliance on outside air for cooling. A robust high-density power and cooling infrastructure is designed to deal with a heating load of 150 Watts per square foot (w/sf) scalable to 230 w/sf, with 100 percent free cooling.
The cold aisle is to be maintained at 78°F (max) between 20 and 80 percent rh (the relative humidity limits are intended to prevent static discharge and condensation). The hot aisle is designed for a 20° rise across the servers. This hot aisle/cold aisle segregation optimizes the outdoor-air economizing potential. Direct evaporative cooling and humidification can support all of the cooling needs of the raised floor area. This design differs from the conventional method of delivering 50 to 55° supply air that mixes with the heat rejected from the server racks. The design will provide up to 75 percent energy savings compared to traditional chilled-water system cooling.
The tile floor is divided at regular intervals by return air grids. Racks of computer servers in the data center are set up on each side of these grids, and air warmed by the data equipment (the hot side) is drawn into the space below. The data center occupies the building’s second story, while the first story serves as a return-air plenum. Exhaust fans in the first story space serve to balance the air pressure inside.
From the first-story space, the heated air is moved to the third story, where it is mixed with outside air as needed to cool the computer servers. In addition to air handlers, this space contains new evaporative cooling equipment that can be used to bring the air temperature down on the warmest days. On very cold days (15°) heat from data servers will warm the building. The evaporative system will also run during the winter to maintain the minimum relative humidity in the space. But that, according to McKinstry engineer Michael Frank, will be rare.
“We will be in economizer operation, mixing return air with outdoor air with no mechanical cooling or evaporative cooling required, for approximately 8,500 hours out of the year, with only 260 hours where we will be using evaporative cooling,” Frank said. “Mechanical cooling is not required for the data center space at all.” The existing chilled water system will serve some support spaces and equipment rooms that were left unchanged during the retrofit.
Publication date: 9/10/2012
Bobbi Kristina và Nick Gordon. Ảnh: Wenn. |
Thái Hòa lần đầu đóng vai phản diện trong "Lấy chồng người ta". Ảnh: BHD. |
Thái Hòa rũ bỏ vẻ hài hước quen thuộc trong các phim trước để tạo một hình ảnh phong trần, dữ dội hơn trong "Lấy chồng người ta". Ảnh: BHD. |
Trong năm tới, Thái Hòa sẽ trở lại với vai "bóng" Phạm Hương Hội trong phần hai của "Để Mai tính" có tên "Để Hội tính". |
Cảnh ùn tắc giao thông trước cửa gian hàng bán bánh trung thu trên phố Thuỵ Khuê, Hà Nội sáng 27/9. |
Cảnh chen lấn mua bánh trung thu tại cơ sở truyền thống trên phố này diễn ra cả tuần nay, trong suốt thời gian mở cửa. |
Người dân sống gần đây cho biết, những năm trước không đông như thế này. "Mấy hôm trước còn chen lấn và xếp hàng kéo dài hàng chục mét. Hôm nay đã vãn bớt đi nhiều rồi đấy", một bác lớn tuổi nói. |
Nhiều người đã phải đến từ 5h30 sáng để chờ gia chủ mở cửa và đợi được mua. |
Bánh tại đây vừa làm mới ra lò vừa bán nên không kịp phục vụ khách hàng. |
Chỉ bán một bán nướng một bánh dẻo, mỗi người chỉ được mua hai hộp, không hơn. |
Giá bánh từ 35.000 đồng đến trên 50.000 đồng một chiếc tuỳ loại nhân. |
Chị Nga nhà ở đường Hoàng Quốc Việt, cách đó hơn 4 km đã phải xếp hàng quay vòng hai lần từ 5h30 sáng để mua 4 hộp bánh. |
Còn chị Hương, nhà ngay gần cửa hàng vài trăm mét cũng phải xếp hàng từ 5h30 sáng. Chị cho biết mua vừa để biếu vừa để ăn và vì quen hương vị bánh cở sở này rồi. |
Khách qua đường thấy xếp hàng mua bánh Trung thu, thấy lạ nên phải dừng lại hỏi han tình hình. |
Trong số những người xếp hàng mua bánh có nhiều người vì tò mò xem ngon đến đâu mà mọi người phải vất vả xếp hàng. Trong khi đó ngay cạnh cơ sở này còn rất nhiều hàng bán bánh trung thu nhưng không có nhiều khách vào mua. |
Lực lượng tự quản phải làm việc liên tục để phân luồng giao thông cho riêng vị trí cơ sở bán bánh. |