Passive design is design that does not require mechanical heating or cooling. Homes that are passively designed take advantage of natural climate to maintain thermal comfort.
Dense materials like concrete, bricks and other masonry are used within the internal spaces in passive design to absorb, store and re-release thermal energy. This moderates internal temperatures by averaging day/night (diurnal) extremes, therefore increasing comfort and reducing energy costs.
Poor indoor air quality may cause a range of health effects from mild and generally non-specific symptoms such as headaches, tiredness or lethargy to more severe effects such as aggravation of asthma and allergic responses. Most of these conditions can also arise from a number of different causes other than the quality of the air in your home.
Passive cooling is when nature helps to cool your home and is the least expensive means of cooling your home. It is appropriate for all New Zealand climates and mainly comprises of natural air flow through the house.
Using energy efficiently is the best way to reduce energy bills and environmental impacts while maintaining or even improving comfort levels. Some solutions cost nothing at all. Most investments in energy efficiency will pay for themselves through lower energy bills.
Use high efficiency gas, electric heat pump or wood heaters (where appropriate) for room heating rather than electric convection and radiant heaters. Radiant heaters are suitable for bathrooms when used for short periods of time.
Electrical appliances account for about 30 per cent of household energy use. Choose appliances with energy or water saving features, such as clothes washers with cold wash cycles, economy or ‘eco’ cycles and load size selection. Avoid using appliances unnecessarily. Dry clothes on a line rather than in the clothes dryer.
Choose the most efficient hot water service and the best energy source to meet your needs. Solar, gas and electric heat pump systems produce far fewer greenhouse gas emissions than conventional electric storage systems. Gas boosted solar is the most greenhouse efficient form of water heating.
You can achieve good passive solar performance at minimal cost if your site has the right characteristics. Where possible, choose a site that can accommodate north facing daytime living areas and outdoor spaces. Permanent solar access is more likely to be achieved on a north-south block. However, on narrow blocks, careful design is required to ensure sufficient north facing glass is included for adequate passive solar heating. Landscape and building form can be designed to deflect and control the flow of breezes or to block unwanted sun. Vegetation can cool and filter air as part of a passive cooling strategy.
When designing an eco house there is no silver bullet. Small, incremental changes to design, build and materials are how we create more efficient, warmer, healthier homes that are also easier on the planet. It's things like making the most of the sun's free heating power, using high levels of insulation, and building in good natural ventilation. Using recycled and sustainable building materials alongside energy and water-saving fixtures and appliances also hugely reduces the home's impact on the environment.
If you'd like to learn more about living eco with an ehouse™, contact us now.