Even when an air conditioner makes it through a summer with little trouble, your monthly bills throughout the season can be quite high. While you’re happy that your air conditioner is functioning well, it drains energy, and it might seem like you have to shut it off completely if you want to try to save money.
There are better ways. An energy audit is an investment in the future of your air conditioner and the energy efficiency of your home.
A home energy audit, or sometimes also known as a home energy assessment is the first step to assess how much energy your home consumes and to evaluate what measures you can take to make your home more energy efficient. An assessment will show you problems that may, when corrected, save you significant amounts of money over time.
Energy Audit is different to an energy assessment
Many suppliers and installers of energy efficient lighting and other technologies offer ‘Energy Assessments’. Be warned an Energy Assessment is not an Energy Audit. An Energy Audit must be conducted to the Australian Standard (AS/NZS 3598:2000); it should offer independent, impartial advice. An energy audit should not try to recommend or sell one particular product.
How a professional energy audit works
An energy audit is a service offered by some local HVAC (heating, ventilation, and air conditioning) contractors in order to help you figure out why your air conditioner is not working as efficiently as it should. Energy audits involve a thorough assessment of your home, not just the air conditioning system itself (although an inspection is usually included).
After testing and inspections of your HVAC equipment, insulation, ductwork, and more, your technician will report back to you about the findings. They might find that you need to make some changes around the home, big or small, if you want to improve the amount of energy used with each cycle and how comfortable you feel.
- Adding blown-in insulations.
- Sealing the ducts.
- Cleaning the ductwork.
- Adding indoor air quality equipment.
- Sealing minor air leaks around doors and windows.
- Updating or replacing AC equipment.
In any case, you should take the initiative to schedule these services with your technician and make sure your home is more efficient for many years to come. Do this before the summer, so that you don’t have to deal with efficiency problems all season long.
Types of energy audits
The Australian Standard (AS/NZS 3598:2000) outlines what an energy audit should cover. The standard specifies 3 levels of energy audits:
A level-1 energy audit is a lower cost, entry-level assessment for your site providing a lower level assessment of energy use and energy saving opportunities. It is useful as a first step investigation into energy saving opportunities. Accuracy: should be within ±40%. Outcome: an abbreviated report with a short list of key energy saving opportunities with rough figures on savings and costs. Next step: you should now have a better understanding of your sites energy usage and options to reduce your energy usage and costs. Further investigation is required to properly cost and assess options. This may be done by seeking quotes from suppliers or conducting a level-2 audit.
A level-2 energy audit provides a more detailed assessment of your site’s energy usage and a more comprehensive analysis of energy and cost savings. It is intended for sites that have some knowledge of energy efficiency and require a detailed assessment of opportunities to reduce their energy consumption. A level 2 energy audit includes a number of items not included in a level-1 audit such as: identifying how and where energy is used, a load profile analysis (instantaneous demand profile for your site), developing an energy performance indicator (e.g. MWh/unit), and measuring light levels to check if areas are overlit and wasting energy. Accuracy: should be within ±20%. Outcome: a full analysis and report providing a prioritised list of energy saving opportunities with estimates on costs and savings. Next step: you should now have a good understanding of your sites energy usage and a prioritized list of options to reduce energy usage and costs. Now you need to decide what options you would like to pursue, seek quotes from at least 3 suppliers, re-assess costing and implement.
A level-3 energy audit provides the most comprehensive assessment of energy usage and a detailed economic analysis of energy-saving opportunities. It may cover an entire site or may focus on one area or process. It requires energy metering and logging which may significantly increase the cost of the energy audit. Accuracy: should be within +10% for costs and -10% for benefits. Outcome: an in-depth analysis and detailed report providing a firmly costed list of energy-saving opportunities. Next step: you should now have all the practical and financial information required to justify implementing an energy saving opportunity. Time to implement.