Proper Energy Management Facilitates High-Performance Results
ASHRAE Bestows Awards for Work Done on Several High-Performance Buildings
Energy management is a top priority, especially when a building’s goal is high-performance recognition. While many different building technologies can be applied to garner high-performance certification, energy and cost savings as well as sustainability and comfort are among the qualities that reveal whether or not the building is achieving the benchmarks of such recognition.
The building projects described below are diverse in many ways, but they share at least two things in common: They provide diagnosed energy savings, and each won a 2014 ASHRAE Technology Award recognizing “outstanding achievements by members who have successfully applied innovative building design in the areas of occupant comfort, IAQ, and energy conservation,” according to ASHRAE’s website. Each project also incorporates ASHRAE standards for IAQ and effective energy efficiency, said the association. This article will look at these award-winning projects, which fall into one of three edifice categories: educational, commercial, or industrial.
SIERR Building at McKinstry Station
David Budd, senior account executive, McKinstry, Seattle, was given first place in the existing commercial building category for the SIERR Building at McKinstry Station, Spokane, Washington. McKinstry, the building’s owner, developer, and prime tenant, performed all of the design-build mechanical, electrical, data, architectural metals, and interior architecture services.
The building was constructed in 1907 and served as an electric railroad car facility for the Spokane & Inland Empire Railroad, and later was used for trucking operations.
When renovating the building, McKinstry put in a ground-source system that provides 60 percent of the heating and 100 percent of the cooling load, which is tied to a hydronic-based system with radiant slabs in perimeter and interior spaces, said Budd. “Due to historic requirements, not all walls could be insulated, and in these spaces, perimeter radiant fin tube heating helps improve occupant comfort. Additionally, the facility’s data center recovers waste heat from the servers and distributes it during cold seasons to reduce overall heating requirements. Ventilation comes via a 100 percent dedicated outside air system [DOAS] that includes an exhaust fan and heat wheel for heat recovery. Transfer fans help ventilate conference rooms located within overventilated common spaces,” he said.
According to Budd, McKinstry worked with local historic preservation agencies and the National Park Service to get the building listed on the National Register of Historic Places. Once the building received this designation, strict requirements had to be adhered to when it came to adapting and modifying the structure. So, balancing historic requirements with green goals proved to be a challenge to the project, one of the greatest of which was “the need to install code-required exterior wall insulation for energy savings versus the National Park Service’s desire to expose as much brick as possible,” said Budd.
Use of the radiant slab system also helps preserve the historic character of the building, Budd said.
300 Davis Street Building
Stephen A. Hamstra, president, Greensleeves LLC, Findlay, Ohio, received first place in the new educational facilities category for the 300 Davis Street Building on the University of Findlay campus. Greensleeves was the mechanical engineer and prime mechanical contractor for the project.
Among the HVAC technologies employed in the building are slab-filled radiant floors for heating and cooling, active chilled beams, a fume hood control system for the laboratories, a heat recovery chiller with three independent geothermal heat exchangers, duct hot water reheat, dual energy recovery wheels in the DOAS, and magnetic bearing compressor technology.
According to Shane Mason, product engineering manager, Greensleeves LLC, management of the independent heat exchangers is at the heart of the control system. “The hybrid predictive controls allow for mean earth temperature reset and elimination of temperature creep by actively managing the heat flux among the three geothermal heat exchangers independently, and by using the hybrid fluid cooler for daily and seasonal preconditioning of the geothermal array year-round.” The control system constantly monitors building and energy plant performance and adjusts its management algorithms, he said.
Mason said the HVAC, lighting, and plug loads are metered separately, which allows each system’s performance to be tracked. Overall, the building uses a lot less energy and, because of the money saved, has a short payback period. “The actual first-year performance of the building showed a 57 percent energy cost reduction (compared to ASHRAE 90.1) and an energy use intensity of 64 kBtu per square foot. Current energy savings are $83,000 per year with a 1.3-year payback,” said Mason.
Packard Foundation HQ
Peter Rumsey, founder and CEO, Point Energy Innovations, Oakland, California, received first place in the new commercial buildings category and the Award of Engineering Excellence, given to the best project from among the first-place Technology Award recipients, for the Packard Foundation Net Zero Energy Headquarters in Los Altos, California. Rumsey was the lead designer and principal in charge of the project.
The challenge of the project was to meet the goals the foundation had for the building: being a net-zero, high-quality, aesthetically beautiful, exceptionally healthy, and highly functional working environment, stated Rumsey. One aspect to the project that made it unique was the design of an enhanced thermal envelope, which includes highly insulated walls and triple-element glazing, which permitted the elimination of perimeter heating systems, Rumsey said.
Among the HVAC technologies the building uses are DOAS for 100 percent fresh air ventilation, chilled beams, and a cooling tower supplying night-time production and storage of medium-temperature water at 55°F, resulting in very low energy and exceptionally high comfort and IAQ, said Rumsey.
The building’s ductwork and piping were designed to reduce energy. Bigger duct and piping was installed and 45-degree, instead of 90-degree, fittings were employed to reduce friction, which, in turn, decreases the amount of energy used by fans and pumps, said Rumsey.
“The current in-operation energy use per square foot is 21.8 kBtu per year.” This is expected to decrease further as enhanced commissioning continues, said Rumsey. And the building is not just net zero, but is a net-positive energy generator, having created 418 MWh of electricity in 2013 with photovoltaic panels while using 351 MWh of electricity and natural gas, he said.
Fromagerie des Basques
Gheorghe Mihalache, engineering director, Atis Technologies, Montreal, won first place in the existing industrial facilities or processes category for Fromagerie des Basques, Trois-Pistoles, Quebec, Canada. The facility is a cheese factory.
There were many goals for this mechanical project. Mihalache said the aims included creating proper production conditions while respecting all sanitary regulations for ventilation, minimizing the energy necessary for production, utilizing proper temperature levels for heating and cooling, separating the mechanical infrastructure from the production area, and making the site able to handle the effluent treatment by transforming it into a valuable combustible for production.
According to Mihalache, one of the main concerns the client had was whey and white water treatment. To deal with this concern, the waste is used to create biogas composed of methane and CO2, which is utilized to create heat to warm the buildings and for production purposes, he said.
Other mechanical changes included adding 100 percent fresh air ventilation in the production area in order to have positive pressure and to satisfy Canadian Food Inspection Agency regulations, preheating the milk for the high-temperature short-time pasteurization process using heat rejected from refrigeration, and implementing a control system that handled surveying the mechanical system, automated control of the main production processes, alarms, and optimization of energy consumption.
All the equipment is now concentrated in three mechanical rooms. The production area has an energy distribution mechanical room, which has heat exchangers, pumps, manifolds with valves, and instruments. “The access here is without sanitary restriction, so the maintenance can be done at the same time as production, without any contamination risk,” Mihalache said. “All distribution lines are corrosion-free, — cross-linked polyethylene (PEX), chlorinated polyvinyl chloride (CPVC), and polyvinyl chloride (PVC) — the buffer tanks are stainless steel, and the loop’s water quality is periodically controlled. Due to heat accumulation, the boilers’ maintenance can be done without any production interruption. With a minimum 85°C in one 35 cubic meter tank and 75° in the other, we have enough energy for one day’s production and a minimum of 12 hours to do boiler maintenance,” he said.
For the cheese-aging room, Mihalache said the air conditioning unit controlling temperature (10-15°) and relative humidity (92-99 percent) were designed to be placed outside the room. This allows cleaning and maintenance to be done without any precautions needed to be taken for the existing cheese in the room. A consequence of placing the unit outside the room is that it created more space for the cheese, he added.
“The project transformed the plant to almost [being] heating independent and [having an] environmentally free impact,” said Mihalache.
Locust Trace AgriScience Farm
Stephanie Gerakos, mechanical engineer, CMTA Consulting Engineers, Lexington, Kentucky, was the mechanical designer on the project and received first place in the new educational facilities category for Locust Trace AgriScience Farm. The career and technical high school is owned by the Fayette County Public Schools in Lexington. On the farm property is an academic building, an arena, and a greenhouse.
The HVAC system includes geothermal water-source heat pumps, radiant heaters, water-to-water heat pumps for building heating, evacuated tube solar thermal panels for building heating, flat plate solar thermal panels for domestic water heating, an energy recovery ventilator (ERV) with energy recovery wheel for building ventilation, and geothermal-cooled coolers for meat and plant storage, said Gerakos.
The building has a 168-panel evacuated tube solar thermal array to offset the heating load. It is capable of generating 1 million Btu, and making hot water for duct-mounted hot water coils, fin tube radiant heaters, and the energy recovery wheel hot water coil. Geothermal water-to-water heat pumps back up the solar thermal system.
Gerakos said there were several major challenges on this project. One was coordinating between the different systems within the building envelope, as most things are exposed on purpose for learning opportunities. Another was the integration of these different systems and the mechanical space planning for these systems. Gerakos said the evacuated tube solar thermal system is a drainback system and requires a large storage tank and the piping to be sloped such that it can get to this tank, which presented an installation as well as a design challenge. Another challenge the solar systems presented was coordinating them all on the roof. “The photovoltaic panels, solar thermal panels, piping for the solar thermal systems, and tubular daylighting devices all require space on the roof. This required several iterations of coordination both in construction and design,” said Gerakos. The final project challenge she named was the installation of the geothermal well field below the permeable paving system.
Publication date: 6/2/2014