Another Option for Improved Building Ventilation
In several of my previous entries, I have mentioned the importance of providing for increased ventilation in order to maintain the health and well being of a building's occupants in tight building envelope construction. We now have another option in the form of a Ground-air Exchange System.
Rehau has introduced such a system that they call REHAU ECOAIR. This system is NOT a geothermal or ground source heat pump in the real sense, but it does function to preheat and pre-cool incoming air for building ventilation purposes. It can, and is often used in conjunction with ground source heat pumps as well as solar systems, both of which Rehau also provides.
In most areas of the USA, the ground temperature at or below seven feet under the surface, is a steady 45 to 54 degrees F (7 to 12 degrees C) year-round. As such, air, when passed through a system of heat exchanger pipes or coils, it will be pre-heated during the winter months and pre-cooled during the summer months. Obviously, this will significantly reduce the amount of energy needed for HVAC systems, especially when combined with a Heat Recovery Ventilation System (HRV).
During the warmer humid months, this system will reduce relative humidity, which is major source of mold, leading to indoor air quality as well as health issues. Rehau has taken the steps needed to control the condensation issues associated with high humid conditions, by providing for condensate drainage, and lining the pipe sections involved with the incoming moist air with silver particles to inhibit mold growth.
One major advantage of this system is that it requires minimal electrical energy to operate. The manufacturer reports that it can raise the incoming air temperature as much as 16 degrees during the winter, and cool the air as much as 30 degrees (in colder, northern portions of the USA) during the summer. This, alone, aid in the optimization of energy, which can aid in earning LEED points in this credit area.
The heart of the system is comprised of an air intake, filter, and condensation control measures, and uses smooth PVC piping to reduce air friction and maximize air flow. The system is available in almost any size or configuration, which means that it can be used in applications as small as a single family home to a large commercial building.
A look at Rehau's web site shows a real commitment to sustainable design, with a wide variety of energy saving designs such as windows and door with U-Values under.25 which exceed both USA Energy Star and Canadian Energy standards. They also are heavily involved with both radiant heating as well as new concept in HVAC -- radiant cooling. (I have written about this in an earlier entry) In fact, they claim that a properly designed and operated radiant heating system can save around 30 percent of the energy that a standard system would normally use. This ties in with their involvement in the manufacturing of PEX tubing, which is the mainstay of radiant heat transfer systems.
Rehau has introduced such a system that they call REHAU ECOAIR. This system is NOT a geothermal or ground source heat pump in the real sense, but it does function to preheat and pre-cool incoming air for building ventilation purposes. It can, and is often used in conjunction with ground source heat pumps as well as solar systems, both of which Rehau also provides.
In most areas of the USA, the ground temperature at or below seven feet under the surface, is a steady 45 to 54 degrees F (7 to 12 degrees C) year-round. As such, air, when passed through a system of heat exchanger pipes or coils, it will be pre-heated during the winter months and pre-cooled during the summer months. Obviously, this will significantly reduce the amount of energy needed for HVAC systems, especially when combined with a Heat Recovery Ventilation System (HRV).
During the warmer humid months, this system will reduce relative humidity, which is major source of mold, leading to indoor air quality as well as health issues. Rehau has taken the steps needed to control the condensation issues associated with high humid conditions, by providing for condensate drainage, and lining the pipe sections involved with the incoming moist air with silver particles to inhibit mold growth.
One major advantage of this system is that it requires minimal electrical energy to operate. The manufacturer reports that it can raise the incoming air temperature as much as 16 degrees during the winter, and cool the air as much as 30 degrees (in colder, northern portions of the USA) during the summer. This, alone, aid in the optimization of energy, which can aid in earning LEED points in this credit area.
The heart of the system is comprised of an air intake, filter, and condensation control measures, and uses smooth PVC piping to reduce air friction and maximize air flow. The system is available in almost any size or configuration, which means that it can be used in applications as small as a single family home to a large commercial building.
A look at Rehau's web site shows a real commitment to sustainable design, with a wide variety of energy saving designs such as windows and door with U-Values under.25 which exceed both USA Energy Star and Canadian Energy standards. They also are heavily involved with both radiant heating as well as new concept in HVAC -- radiant cooling. (I have written about this in an earlier entry) In fact, they claim that a properly designed and operated radiant heating system can save around 30 percent of the energy that a standard system would normally use. This ties in with their involvement in the manufacturing of PEX tubing, which is the mainstay of radiant heat transfer systems.
Posted by Alan L. Englander at 4/26/2009 5:35 PM 
Categories: Heat Revovery Ventilators, Tight Building Envelopes, Indoor Air Quality, Ground-Air Heat Exchange
Categories: Heat Revovery Ventilators, Tight Building Envelopes, Indoor Air Quality, Ground-Air Heat Exchange
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