Have you ever imagined how much you would save in heating and cooling on an annual basis if your AC or heat pump is switched off over the entire duration? The Department of Energy estimates that HVAC consumes close to 50% of the total energy bills in an average American household. This means if you don’t use your HVAC unit, you can slash pretty much of your electricity bill.
However, in reality, you can hardly survive without heating and cooling even in temperate climates. The only chances of surviving are when living in a passive house. These are simply residences which employ a combination of airtight building envelops, high performance insulation, and passive heating and cooling techniques.
What Categorizes a House as Passive?
Passive homes have different techniques they use to achieve their goals. There are certain standards they have to meet for them to be certified as official passive houses. The following are the criteria:
• Space Heating Demand – In the house, the heating should not exceed 15 kilowatts per square meter of treated floor annually. Alternatively, it should not exceed 10 watts per square meter during peak demand times.
• Space Cooling Demand – The same metrics used for heating demand above affect cooling demand. In addition, an allowance should be made for dehumidification which largely depend on your climate.
• Primary Energy Demand – The home must use less than 120 kwh on an annual basis for its total energy consumption together with heating and cooling demands.
• Airtightness – The homes must pass a blower test as this is a key indicator of air tightness. The quantitative indicator for this is 0.6 air changes per hour at a pressure of 50 pascals.
• Thermal Comfort – All the parts of your home must be below 25 degrees Celsius for at least 90% of the time.
Passive House Certification and LEED
LEED certification is a green home labelling standard used in the United States to rate sites across a number of measurements including energy efficiency, air quality, sustainability of the materials, and encouragement of greener behaviors such as biking to work and recycling.
The passive homes certification focuses entirely on the efficiency of homes when it comes to maintaining comfortable temperatures throughout the year.
Contrary to what some people may think, passive house standard is not just a preserve for newly constructed buildings, but you can also retrofit existing homes. By renovating to fit these standards, your home can be 75 to 90% more energy efficient than it currently is. The only investments you will have to make are thermal insulation, air-tightness, heat recovery systems, renewable energy sources, and high-performance windows and glazing.
It is therefore possible to reduce your energy use without compromising on the quality of heating and ventilation in your home. Passive homes is the way to go as each one of us embraces the path to a greener world.