Passive Cooling

Passive Cooling

If you let hot air escape up high, you can let cool air replace it down low and at night, this is the essence of passive cooling. It works by using the difference between day-time and night- time temperatures.  Control of summer heat through shading, window orientation and passive ventilation helps to limit the cooling load. Any backup heating or cooling demand is provided by an extremely small source instead of a conventional HVAC system.

Passive Cooling is one component to a Passive House system.  The Passive House system is a very well insulated, virtually airtight building that is primarily heated by passive solar and internal heat gains from occupants, cooking, bathing, electrical equipment, etc. The Passive House Standard is the highest building efficiency standard in the world, with the promise of reducing the energy consumption of buildings by up to 80% while providing superior comfort and air quality – all at minimized additional upfront cost. When coupled with renewable energy systems, such as solar, Passive House puts true zero energy buildings within reach.  If you are interested in the entire system, please look into adding on Passive Solar, Constant Fresh Air, Highly Insulated, Double or Triple Glazing Windows (dependent upon climate), Slab Foundation and Heat Recovery Ventilation –HRV to your OHOME/C-ROOM.

Environmental Benefits

Wide use of air-conditioning units has caused a shift in electrical energy consumption to the summer season and an increased peak electricity demand.  Peak electric loads impose an additional strain on national grids, which can only be covered by development of extra new coal-fired power plants.  It is estimated that in the USA the total electrical peak load induced by air conditioning units is about 38% of the non-coincident peak load.  Coal fired power plants burn and emit approximately 0.5 kg of carbon in the form of CO2 for each kWh generated.  Using Passive Cooling design in buildings can save at least 2.35% of the world energy output and greenhouse gas emissions.  Even in areas with average maximum ambient temperature around 89 degrees Fahrenheit, comfortable conditions inside buildings can be achieved by means of proper building design such as the OHOME/C-ROOM’s Passive Cooling system, making the use of air-conditioning units in dwellings unjustified.

Health and / or Social Benefits

Health problems linked to aging coal-fired power plants shorten nearly 24,000 lives a year, including 2,800 from lung cancer. The threat of climate change and the risks related to our dependence on petroleum are among the greatest threats we face as a nation and as a species. Shifting to sustainable construction practices such as Passive Cooling reduces CO2 emissions and can save lives by eliminating the demand for coal-fired power plants.

Economic Benefits

The Passive Cooling approach reduces construction costs through energy efficient design.  Adding Passive Cooling dramatically increasing the energy efficiency of a building and the HVAC system can be downsized or even eliminated (dependent upon climate). This efficiency “sweet spot” is a basis for the Passive Cooling performance standard and the key to its financial feasibility.  Additionally, much smaller solar systems are required to reach zero energy; this saves costs both upfront and annually for the lifetime of the OHOME/C-ROOM.  In addition to environmental implications, increased electrical peak loads result in an increase of the average cost of electricity to cover the construction of new power stations.