solar skin NET ZERO BUILDINGS HVAC: VARIABLE REFRIGERENT FLOW POWER: BOTH SIDES OF THE NET WATER: DIVIDING LIQUID ASSETS

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1 NET ZERO BUILDINGS Highlighting the Path Toward Net Zero Building Design NET ZERO BUILDINGS September 2013 Volume 2, Number 3 solar skin HVAC: VARIABLE REFRIGERENT FLOW POWER: BOTH SIDES OF THE NET WATER: DIVIDING LIQUID ASSETS As designers and owners contemplate how to integrate renewable power sources, such as solar, into their projects, they re realizing it often takes more square footage than is available on many roofs. One option integrating PV into the curtainwall.

2 JOHN MESENBRINK HVAC NZB: HVAC New Kid on the Block Variable Refrigerant Flow (VRF) zoning systems provide one of the most flexible, cost-effective and environmentally friendly HVAC options in commercial construction today. A relative newcomer, VRF systems are estimated to achieve nearly 34% and higher energy cost savings. John Mesenbrink has been covering the building and construction industry for more than 15 years, focusing his efforts on the plumbing and HVAC industries including the launch of his website, which focuses on the installation side of mechanical systems. As far as innovations in HVAC, variable refrigerant flow (VRF) technology is a relative newbie when compared to traditional ducted systems. With adjectives like space saving, energy efficient, environmentally friendly words that are music to a designer s ears it s no wonder that VRF is getting a closer look from building and construction professionals, especially when considering net zero. The architectural and engineering community is adopting a balanced design approach that considers energy and water consumption, repetitive maintenance costs, the impact of development on the environment, and the building s initial cost as equally important factors in developing high-performance, sustainable buildings that will increase building value. VRF systems help achieve points for sustainability programs, says Lorie Quillin Bell, director Go-to-Markets for Commercial Air Conditioning, LG Electronics. The variable in VRF refers to the ability of the system to control the amount of refrigerant flowing to the multiple evaporators (indoor units), enabling the use of many evaporators of differing capacities and configurations connected to a single condensing unit. The systems are small, modular and can be installed without the use of a crane. VRF zoning technology is an energy-efficient method of providing precise comfort control to indoor environments, and it is these zoning systems that are designed to help buildings earn green building certification, including net zero status. This method is ideal for a wide variety of new construction or retrofit applications, including large commercial buildings with multiple floors and areas that require individual comfort control, says Mike Smith, senior marketing manager commercial products, Mitsubishi Electric U.S. Cooling & Heating Division. VRF zoning systems allow architects and engineers to design according to aesthetic rather than designing spaces around HVAC equipment. 42 According to the EPA, at least 45% of energy use in commercial buildings is attributable to cooling and heating expenses, and it has been estimated that fan and duct losses of a conventional system can add up to 30% to the DATAPOINT total energy consumption of a particular commercial building. According to the EPA, at least 45% of energy use in commercial buildings is attributable to cooling and heating expenses. 45% Heating & Cooling Expenses Invented in Japan more than 20 years ago, VRF technology employs an outdoor condensing unit, typically located on the roof, and multiple indoor fan coil units. Instead of utilizing bulky ducts to move air, flexible small-diameter copper tubing is used to move refrigerant from the outdoor condenser. The system is capable of simultaneously cooling one area while heating another, and can transfer heat from spaces being cooled to spaces being heated, and vice versa NET ZERO BUILDINGS

3 Introducing Simplifying the Specification of Stone Wool for Commercial Projects The Latest Product Information Individual Product Specifications Case Studies & Projects Continuing Education Technical Information Custom Virtual Portfolio CIRCLE 35

4 HVAC CASE STUDY SFPUC HEADQUARTERS San Francisco, Calif. The San Francisco Public Utilities Commission (SFPUC) headquarters at 525 Golden Gate called the greenest office building in North America opened to widespread acclaim for its sustainability and energy savings. Compared to similar 13-story office buildings, 525 Golden Gate produces 50% less of a carbon footprint and uses 32% less energy and 60% less water. After factory certified testing to AHRI Standard 550/590 for water-cooled chillers, two Daikin McQuay Magnitude chillers were selected one 500-ton and one 250-ton unit. With their magnetic bearing, oil-less compressors and integral variable frequency drives, these chillers are 40% more energy efficient than traditional centrifugal compressor chillers. The building s HVAC system design is based on a traditional four-pipe system and includes the two chillers, two rooftop cooling towers for the chilled water system, two large variable air volume (VAV) customer air handling units, heat exchangers and an underfloor air distribution system that conserves building space and minimizes ductwork and uses personal control of airflow. As far as zones, they re single- or multipleroom spaces that, according to the function or preferences of each space, are conditioned to a set temperature and are operated independently from other rooms. As far as up-front costs, once contractors and architects get a solid footing on the technology, it becomes clear that the solution is not cost-prohibitive at all. Although the technology may have higher initial costs than older technologies, the ROI for building owners is tremendous, says Bell. Using VRF systems, he says, provides commercial businesses more precise climate control, eliminating excessive energy usage. These efficiencies, combined with the ease of design, installation and ease of maintenance, lead to a very favorable total cost of ownership, and often contribute to a higher ROI with VRF systems than conventional HVAC systems. VRF systems are also engineered to save on the cost of ducts, distribution fans, water pumps and water piping. VRF systems have a lower life cycle costs than any other technology on the market today, adds Bell. Throw in the fact that, depending on the style of the building, VRF zoning systems tend to have fewer components than conventional HVAC systems, reducing equipment costs, complexity and installation time. Although VRF zoning technology is advanced, the system is relatively simple to install and maintain. The system components are small, resulting in less labor, fewer materials, easier installation and a lower operating cost, says Smith NET ZERO BUILDINGS

5 H VAC VRF 101 ADVANCES TWO PIPE HEAT SYSTEM Cooling Mode Split-type air-conditioning systems are one-to-one systems consisting of one Creating energy efficient buildings with VRF systems offer architects and building owners the opportunity to design and install HVAC units that aren t limited by ductwork runs. evaporator (fan coil) unit connected to an TWO PIPE HEAT SYSTEM Heating Mode Heat is exchanged intelligently between zones to meet the diverse comfort requirements of each individual zone. external condensing unit. Both the indoor and outdoor units are connected through copper tubing and electrical cabling. The indoor part (the evaporator) pulls heat out from the surrounding air while the outdoor condensing unit transfers the heat into the environment. A multi-type air-conditioning system operates on the same principles; however, in this case, there are multiple evaporator units connected to one external condensing unit. The use of optimized scroll compressors, THREE PIPE HEAT SYSTEM Simultaneous Cooling & Heating VRF systems are capable of simultaneously cooling one area while heating another, and can transfer heat from spaces being cooled to spaces being heated, and vice versa. Illustration: Johnson Controls special heat exchangers, with inverter technology to a low part load condition minimizes energy consumption to levels previously unattainable by non-vrf systems. The modular design offers comfort on demand allowing the choice to use the system only in the zones where it is needed further promoting reduced energy consumption. The greatest contributor to system-wide energy efficiency is the employment of an inverterdriven compressor, a highly responsive, highly efficient component that ensures the Inside the Technology VRF systems increase efficiency by providing cooling or heating only to the individual zones where comfort conditioning is required. VRF system adjusts to temperature fluctuations. Power consumption is reduced because the system operates only at the levels needed to maintain a constant, comfortable indoor 44X environment. PACKAGED AIR Modine has expanded its Atherion commercial packaged ventilation line with the introduction of the 7- to 15-ton B-cabinet. The expansion gives the full Atherion line eight models ranging from 7to 30-tons. Designed to meet ASHRAE and 62.1 standards for IEER efficiency and indoor air quality, the Atherion features optional highefficiency gas heating and best-in-class MERV16 air fi ltration. Its Energy Recovery Module (ERM) option makes the Atherion a high effi ciency, 100% dedicated outside air unit. With an airflow range of 1,111 to 6,000 cfm, Modine s B-Cabinet line includes 7-, 10-, 13- and 15-ton sizes, and offers single (7-ton only) and tandem set modulating digital scroll compressors and a gas heat range of 150 to 400 MBH at 80% efficiency, or, 175, 225 or 310 MBH furnace options producing heat at 94% efficiency. Modine Mfg. Co. CIRCLE 297 zoning systems offer on-demand cooling and heating for individual zones which reduces energy consumption and consists of a type of direct expansion (DX) multi-split system that incorporates a variable capacity compressor with a network of multiple indoor fan coil units. Every feature from a VRF system, from the compressor speeds, the expansion valve setting and the fan speed, has been optimized to produce the greatest efficiency, says Brendan Casey, commercial product manager, Fujitsu General America, Inc. NET ZERO BUILDINGS

6 HVAC CASE STUDY MILE HIGH MUSEUM Denver, Colo. The team at MKK Consulting Engineers was interested in finding a reliable, highperformance HVAC system to protect the 200,000-sq.-ft. History Colorado Center museum s eight vital nerve centers four electrical rooms containing large transformers, switchgear, Cisco network equipment, lighting and breaker panels, and four data closets loaded with database servers, IP phone connectivity, fiber optic equipment, an analog phone network, security equipment and point-of-sale equipment. With the constant heat gain from these eight centers, MKK needed a bulletproof, mission-critical system to keep the temperature in these rooms at the constant 76 F required by the State Office of Information Technology (OIT). The eight crucial nerve systems in the History Colorado Center needed to have reliable temperature control when Rocky Mountain temperatures dipped below 0 F, as they often do. The design team was urged to consider specifying a Variable Refrigerant Flow (VRF) zoning system from Mitsubishi Electric equipped with a Low Ambient Cooling Kit, which guarantees cooling operation down to -10 F. 43 To better understand the inverter-driven compressor concept, Mitsubishi s Smith explains, Let s compare its operation to a car s cruise control. Just as a car s cruise control speed is set by its driver, the room s occupant chooses the room s temperature for the inverter-driven compressor. While on long stretches of road, the car s engine works automatically to maintain the speed as you drive up and down hills and around curves. An inverter-driven compressor adjusts to maintain the desired set point. After it has been achieved, an inverter-driven compressor works at a lower speed to maintain the set point. The inverter compressor varies its speed to match the temperature demand, thereby consuming only the minimum energy that is required. Compare this to a conventional single-speed compressor that starts and stops, much like a car in city traffic, consuming more energy and reducing compressor life. The Design Space Specifying Mitsubishi Electric s VRF zoning system made better sense because it serves up to 50 indoor units with one outdoor unit, greatly reducing the number of condensing units on the roof. This leads to a reduction of electrical connections and roof penetrations. BECAUSE VRF SYSTEMS UTILIZE REFRIGERANT PIPING TO DISTRIBUTE CAPACITY, THERE S NO AIR LOSS WHEN COMPARED TO DUCTED SYSTEMS. VRF zoning systems give architects and engineers more options, allowing them to design according to aesthetic rather than designing spaces around HVAC. The systems allow architects to add up to 10% to interior spaces by creating additional floor-to-ceiling height. Components of the system can be installed in smaller indoor/outdoor spaces, requiring less mechanical room space, says Smith NET ZERO BUILDINGS

7 HVAC VRF systems remove losses that are unavoidable in other ducted systems. And, because VRF systems utilize refrigerant piping to distribute capacity, there s no air loss when compared to ducted systems. This benefit alone can contribute 30% to comparative energy savings. A noisy air-conditioning system can be a distraction for employees and lead to complaints from tenants. Operational sound levels of VRF zoning systems are significantly lower than those of conventional central forced air or boiler systems. Sound levels in the condensing units are greatly reduced because the inverter-driven compressor modulates up and down smoothly. The compressor also is housed in its own compartment surrounded by sound insulation. The condenser fan rarely runs at full speed and is designed for quiet performance. Sound levels for the outdoor units range from 19 db(a) at low speed to 49 db(a) at high speed quieter than a refrigerator. Indoor units are also extremely quiet, with sound ratings as low as 29 db(a), essentially quieter than a human whisper, adds Smith. Designed to blend into their environments, multiple styles of compact indoor units can be installed in many different locations, including within the ceiling, high or low on walls or on the floor. System configurations allow for architects to design to the aesthetic vs. sacrificing interior design based on limitations of conventional central ducted system. Compact outdoor units also offer greater design flexibility than traditional heat pumps. Available in air- or water-source models with a wide variety of capacities, these modular systems are easy to install and can be tailored to almost any building design, including placement on a rooftop. Compact units can be transported to the floors or the roof via the elevator. VRF systems are 31% lighter than chilled-water systems, so they are easier to handle and cost less to transport. Moreover, the load can be distributed across an existing structure or avoided by mounting on the ground. Because of the ease of installation, VRF zoning systems are ideal for retrofitting older buildings with minimal disruption to the existing structure, says Smith. It s hard to imagine any commercial building where VRF wouldn t be ideal. A very large space with a single set temperature and where noisy HVAC equipment is acceptable is not a good application for VRF, says Casey. A truly comprehensive comparison of up-front HVAC costs includes more than equipment. It is important to keep in mind potential hidden costs such as consulting/engineering design costs, installation tooling, rigging and labor, potential electrical and/or structural modifications in a building, complexity of connecting outdoor and indoor equipment and controls integration. CASE STUDY SOHO RENOVATION The Soho project involved the careful renovation of a historic 10-story building, originally constructed in One of the key components of the retrofit was replacing an outdated HVAC system comprised of selfcontained vertical units on each floor, including a maintenance operation s room. In collaboration with mechanical engineers at Guth DeConzo Consulting, the WeWork construction team determined that a VRF system was the best solution, while working within the constraints of the building s historic architecture. LG s Multi V III Heat Pump system was the only solution that could fit within the limited footprint on the rooftop and offer both horizontal and vertical piping distances required to deliver custom temperature control to more than 50 individual zones on multiple floors. Establishing WeWork collaborative work environments often involves retrofits of existing buildings. In 2012, WeWork identified a 75,000-sq.-ft. space in New York s Hudson Square/Soho West neighborhood to renovate for shared office space, in addition to housing WeWork Labs, the company s organization for start-ups. NET ZERO BUILDINGS

8 HVAC CASE STUDY COVE AT YARMOUTH West Yarmouth, Mass. The Cove at Yarmouth, a 229-suite resort, has a high demand for hot water. But it was throwing money down the drain with its former hot water heating system. Within an eight to 10 year period, the resort had been replacing tanks at a rate of one to two per year. Management decided it was time to make a change. Hybrid water heaters from Eternal were recommended because of the equipment s dependability, ease of installation and mainly, energy efficiency. The retrofit of the resort s hot water system from a traditional system to a hybrid system was an easy decision as beyond significant energy savings, the resort had to replace 1-2 hot water tanks per year. Before the retrofit, the Cove had 23 standard 100-gallon, 199,000 BTU hot water tanks that also served the resort s restaurant, athletic facilities, laundry rooms, and other common area restrooms. The retrofit involved the installation of 21 Eternal GU195S water heaters and five storage tanks. The unit provides endless hot water, but unlike a tankless system, it has a small reserve tank inside to maintain water pressure and avoid temperature fluctuation. One of the storage tanks, in this case, is 80 gallons, and the other four are 120-gallon tanks. The system allows installers to use a single unit or multiple units with additional storage to accommodate large applications that have an unpredictable high demand for hot water. Installation of the system has led to a 12% reduction in the complex s energy bill, roughly a $1,400 a month savings. It was a seamless installation that went smoothly, said Service Manager Richard Toma of Murphy s Air Conditioning, Heating and Plumbing, who attended a training class on the system. I felt Eternal offered amazing tech support, he said. Eternal offers 98% efficiency, is lead free, has close to zero carbon emissions, and exceeds Energy Star standards. STUDIES HAVE FOUND THAT OFFICE BUILDINGS 50,000 TO 100,000-SQ. FT. DEMONSTRATE THE BEST RETURN ON INVESTMENT FOR INTEGRATED SYSTEMS. IN THE NEWS CABA Launches Research Project The Continental Automated Buildings Assn. (CABA), through its Intelligent & Integrated Buildings Council, has launched a collaborative research study entitled Life Cycle Costing and Intelligent Buildings. The core objective of the project is to identify what needs to be done, and by whom, to make life-cycle costing a mainstream criteria for building system evaluation. A previous CABA assessment found that office buildings of 50,000 to 100,000-sq. ft. demonstrated the best return on investment for integrated systems, but that there was a lack of tools to evaluate life cycle costs. CABA s new project will identify barriers to adopting life-cycle costing and determine what issues need to be rectified in order to make processes more understandable. The report will outline the current state of life-cycle cost adoption in today s commercial buildings market and identify the key influencers across the value chain. The report will also identify what are the most effective lifecycle cost value propositions that resonate with these decisionmakers. The research will also be designed to identify the challenges and opportunities that exist for broader adoption of life-cycle costs techniques within the value chain and identify who is best positioned to carry the value proposition to decision makers and develop recommendations. The study is expected to be completed this fall NET ZERO BUILDINGS