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REHAU Radiant Heating and Cooling Systems Paired With Geothermal Systems Are Key Steps on the Path to Net-zero Building.

Hydronic radiant heating and cooling systems combined with downsized air-handling systems can reduce HVAC energy consumption and initial investment costs while increasing thermal comfort in commercial buildings. When further integrated with a renewable energy source, such as the REHAU RAUGEOTM ground loop heat exchange system, REHAU radiant heating and cooling systems make a significant contribution toward high-performance and net-zero building.

A recent study by the New Buildings Institute found nearly half of the zero-energy buildings in the United States incorporate radiant systems to meet their energy goals. The study also notes that these systems are often integrated with ground sourced heat pumps (GSHPs) to achieve zero energy as part of a cost-effective package.

REHAU Radiant Heating and Cooling Systems
REHAU offers its radiant heating and cooling system as one of the most comfortable and efficient space conditioning solutions available today. Radiant heating and cooling systems work by circulating fluid through a network of RAUPEX® O2 Barrier crosslinked polyethylene (PEXa) pipes placed in the floors, walls or ceilings. When the circulating fluid is warm, heat is gently radiated from the panel, warming the surfaces, objects and occupants in the room and eliminating drafts and hot spots. When cooled fluid is being circulated through the pipes embedded in the building structure, radiant cooling evenly absorbs heat energy, cooling the space to a comfortable temperature.

Used in combination with a downsized air-handling system, a hydronic radiant heating and cooling system can condition a space very efficiently. By reducing the load on the air-handling system with more efficient hydronic energy transfer, radiant systems can not only reduce energy costs by 30 percent or more, but can also lower initial investment costs by allowing the air-handling system to be downsized.

In addition to saving energy, radiant heating and cooling systems that use moderate water temperatures pave the way for integrating a water-to-water geothermal heat pump system for maximum efficiency. A ground source heat pump system can reduce energy costs by up to 70 percent in the heating mode and up to 50 percent in the cooling mode.

“Integrating a REHAU radiant heating and cooling system with alternative energy sources such as geothermal heat exchange offers added energy conservation,” said Mike Dietrich, director of the building technology business unit at REHAU. “The wonderful thing about pairing radiant with geothermal, is that because we run at very moderate supply fluid temperatures, typically 100-120°F (38-49°C) in heating mode and 55-60°F (13-16°C) in cooling mode, we are operating in some of the highest coefficients of performance for the geothermal equipment. This added optimization makes an already low-energy radiant system work at unprecedented levels of efficiency.”

REHAU Geothermal PEXa Piping Systems
Geothermal systems exchange energy from the earth to heat and cool at a fraction of the operating costs of traditional HVAC, with potential energy savings up to 70 percent. The REHAU RAUGEO™ ground loop heat exchange system employs a unique design and innovative materials to provide numerous advantages over traditional geothermal systems.

The RAUGEO crosslinked polyethylene (PEXa) piping system offers superior flexibility and abrasion resistance compared to HDPE, while pre-formed double U-bends require up to 30 percent less borehole footage than a single HDPE U-bend. RAUGEO ground loops usually begin and end at a balancing manifold that, unlike the typical reverse-return header, allows each ground loop to be individually controlled for system optimization.

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RAUGEO PEXa pipe and compression-sleeve fittings are now recognized by both the International Ground Source Heat Pump Association's (IGSHPA) "Design and Installation Standards 2008 Edition" guide and the CSA Group Standard C448/13 “Design and Installation of Earth Energy Systems.”

REHAU PEXa Pipe Technology From Heat Source to Distribution System
REHAU offers both radiant heating and cooling systems and geothermal ground loop heat exchange systems based on crosslinked polyethylene (PEXa) pipe technology. PEXa technology enhances temperature and pressure capabilities as well as long-term strength, flexibility and thermal memory, providing ease of handling and kink repair in the field. These attributes support the optimization of REHAU system designs with proprietary features including secure compression-sleeve joints and high-output double U-bend vertical ground loops.

In addition to PEXa pipe, REHAU radiant systems comprise the EVERLOC® compression-sleeve fitting system and pre-assembled PRO-BALANCE® manifolds which offer individual circuit balancing and purging capabilities. The RAUGEO™ ground loop heat exchange system from REHAU uses these technologies for the ground loop portion of the geothermal heat pump system, allowing contractors to employ the same innovative, high-performance products for both the heating/cooling source and heating/cooling distribution system.

REHAU Engineers Will Present During AHR Education Session on Hydronics, Net Zero
To learn more on the topic of hydronic radiant systems and net zero building, register for the Radiant Professionals Alliance-sponsored AHR session “The Path to Net Zero Through Hydronics.” REHAU engineers will be among the presenters, who will address the construction of newer Super Insulated Passive style homes, and demonstrate how hydronics can effectively be used in the heating and cooling these low energy use homes.

Further details about REHAU radiant heating and cooling and geothermal ground loop heat exchange systems can be found at http://na.rehau.com/mp.

For additional information on REHAU’s complete line of mechanical solutions contact REHAU, 1501 Edwards Ferry Rd., N.E., Leesburg, Va., 20176. Phone: 1.800.247.9445. Fax: 1.800.627.3428. E-mail: rehau.mailbox@rehau.com.
Web site: http://na.rehau.com/mp.

REHAU delivers “Unlimited Polymer Solutions,” and is the premium worldwide brand for polymer-based innovations and systems in construction, automotive and industry. The company generates continuous growth through its expertise and innovative capabilities in materials development, systems design and surface technology. Approximately 18,000 employees at more than 170 locations around the world ensure success of the independent, privately held company.


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