There are two things to consider when heating a house that is off the grid:
1. Getting the heat into the house, and
2. Keeping it there!
How to Heat Your Home
The most comfortable off grid houses use a combination of heating technologies. These generally are:
A wood heater (aka slow combustion heater) or fireplace are commonly used in Australia. On top of their heating abilities, they can compliment a home and create a certain ambience.
Of the two, the modern design of the wood heater has proven to be more efficient. Heat is radiated out from the metal body of the heater and flue, and hot air can be released via specially designed vents. The wood heater emits a lot of heat, and has proven effective for heating large areas for extended periods.
When choosing a wood heater opt for quality over price. Remember this is an investment in your comfort as well as a way to save costs in the future. Ensure too, that your wood heater comes with a current Certificate of Compliance.
Cleaning and maintenance is a fact of life with wood heaters and fireplaces. Flues and chimneys need to be cleaned regularly, so add that to your calendar. You should also keep in mind that any wood fire is a potential fire and smoke hazard, and needs to be treated with caution.
Solar Thermal Energy (via passive solar design)
Energy (heat) from the sun can be allowed into your home via your house design. It includes simple things such as the glass of living areas facing north. Cleverly designed homes trap heat through materials that have a high thermal mass (eg. masonry). The properties of these materials allow the heat to be released as temperatures fall – usually at night.
Reverse Cycle Air-conditioning
Reverse cycle air-conditioners absorb heat from the outdoor air and warm the air inside your home. While reverse cycle air-conditioners are great for taking the chill out of the air in winter, if you plan on using one as your primary source of heating, make retaining that heat in your home a priority.
Gas (if you have it)
Keeping the Heat In
Regardless of how you get heat into your house, keeping it there can be a challenge.
Here are some practical ways to keep that warmth in:
Sealing to Stop Draughts
Make Use of Thermal Mass
Clever House Design
These four strategies for retaining heat really do come down to the design of your home and the quality of the work performed when building it.
Many homes – off grid and standard – make use of insulation, but fail when it comes to tight sealing, having the right proportions of thermal mass for the local climate, and designing the right sized rooms and ceiling heights with thermal efficiency in mind, as well as being able to zone the house.
Keeping the heat your home is a delicate art that is worth the effort to get right. When you are living off the grid you have less electricity to play with in the winter months, so unless you have made the plan for it, you won’t be able to plug in an electric wall heater. And one last tip: use an authentic and experienced green building designer to plan your home.