The improved design of today’s homes has increased the energy efficiency of a house, dramatically reducing energy costs but creating an environmental problem by trapping pollutants and humidity which could be a threat to your families’ health and comfort. A better insulated house combined with energy efficient doors and window systems creates a shell, trapping humidity, cooking odours, dust, and cigarette smoke, chemical off gassing of carpeting, furniture, building materials and plastics. This stale air could cause or aggravate numerous health conditions including asthma. Humidity caused by cooking, laundry, showers and occupants is trapped within the house causing the warm humid air to condense on cold surfaces like windows and walls. The moisture stains paint, corrodes plaster encouraging mould growth and may cause structural damage. Heat Recovery Ventilation (HRV) units can eliminate these problems. The compact electrically powered HRV moves stale, contaminated, warm air from inside the house to the outdoors. At the same time it draws fresh, oxygen laden air from outside and distributes it throughout the house. As the two air streams pass through the HRV they do not mix. They pass on either side of an aluminum heat exchange core which transfers heat from the outgoing air to the incoming air. The efficiency of the HRV is so great that virtually none of the warmth collected from your home is lost to the outside. Related Link
Heat recovery ventilation
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Heat recovery ventilation, also known as HRV, mechanical ventilation heat recovery, or MVHR, is an energy recovery ventilation system using equipment known as a heat recovery ventilator, heat exchanger, air exchanger, or air-to-air heat exchanger which employs a counter-flow heat exchanger (countercurrent heat exchange) between the inbound and outbound air flow. HRV provides fresh air and improved climate control, while also saving energy by reducing heating (and cooling) requirements. Energy recovery ventilators (ERVs) are closely related, however ERVs also transfer the humidity level of the exhaust air to the intake air. Contents * 1 Benefits * 2 Technology * 3 Air to air heat exchanger * 3.1 Incoming air * 4 Earth-to-air heat exchanger * 4.1 Air quality * 4.1.1 Radon * 4.1.2 Bacteria and fungi * 5 Earth-to-Water heat exchanger * 6 Seasonal bypassing * 7 See also * 8 References * 8.1 Sources * 9 External links * 9.1 Non-commercial links| Benefits
As building efficiency is improved with insulation and weatherstripping, buildings are intentionally made more airtight, and consequently less well ventilated. Since all buildings require a source of fresh air, the need for HRVs has become obvious. While opening a window does provide ventilation, the building's heat and humidity will then be lost in the winter and gained in the summer, both of which are undesirable for the indoor climate and for energy efficiency, since the building's HVAC systems must compensate. HRV introduces fresh air to a building and improves climate control, whilst promoting efficient energy use. Technology
HRVs and ERVs can be stand-alone devices that operate independently, or they can be built-in, or added to existing HVAC systems. For a small building in which nearly every room has an exterior wall, then the HRV/ERV device can be small and provide ventilation for a single room. A larger building would require either many small units, or a large central unit. The only requirements for the building are an air supply, either directly...