Zero-energy Homes: Tips to improve energy efficiency in the home
An entire zero-energy home consumes as much energy as is needed to run a hair dryer! Super insulated, energy efficient, zero-energy homes produce at least as much energy as they consume, on an annual basis. As Building Sciences evolve, the principles used in zero-energy homes are commonly being incorporated into new and existing structures and there are many simple and significant changes that can reduce the energy bill while building equity in the home.
Take advantage of natural energy sources:
Producing energy can be as simple as orienting one’s house in order to gather as much sunlight as possible. Properly oriented (south facing) windows will help heat the interior. Solar panels (photovoltaic’s) on the roof generate electricity to power the home. Hot water heating can be assisted by solar panels on the roof and, in BC’s lower mainland, can supply about 70% of domestic water needs. Almost any house can take advantage of sunlight and an important factor to remember is that the more energy efficient the house is, the less equipment will be needed to heat and power it.
Optimize energy efficiency in the home
Energy efficient homes are well insulated and airtight. A simple heating system is all that’s needed since the energy requirements are very low compared to conventional houses. Insulation is a great investment; it’s a one-time purchase that lasts the life of the house, providing warmth and reducing energy consumption. An HRV (heat recovery ventilator) supplies fresh air to the house interior while recovering heat from the stale air being removed from the house. HRV’s are excellent for people with respiratory conditions since they keep the indoor air clean and separate from outdoor air. An HRV is best installed during construction but can be added to an existing home.
Energy efficient houses are energy producers.
Most houses are tied to the electrical grid, zero energy homes included. Electricity needed to cover peak loads can be supplied by the existing grid. Excess electricity generated when power consumption is low can be sold back to the company operating the electrical grid. This is called net-metering. In Canada the amount credited depends on the agreement with the electrical supplier.
Energy efficient windows are essential in reducing energy consumption.
Low-e windows control heat loss and gain by way of coatings on the glass that keep radiant energy on the same side of the glass that it originated on; this keeps warm air indoors in winter and reflects the sun’s infrared radiation away during the summer.
Make a change to energy efficient light fixtures and appliances.
Using energy efficient appliances and light fixtures can also improve energy efficiency and further reduce your energy consumption footprint. LED (Light Emitting Diode) lighting is showing great promise and is much more energy efficient than CFL’s (Compact Fluorescent Lights). Similar to traditional incandescent bulbs, LED’s respond instantly and can be dimmed.
A few small changes can improve energy efficiency.
Water consumption is easily reduced by low flush toilets and low flow faucets. Heat from shower and bath water can be routed through a simple copper heat exchanger under the tub or shower to heat cold incoming water. Waste “grey water” can also be used to water gardens instead of pouring it down the drain.
Building a new and zero-net energy home may not be in most people’s budgets; however there are many ways to update an existing home that won’t cost the earth and will still improve the energy efficiency of the home.