How to Energy Audit Your Home
When you think of ways to reduce your energy usage, the thermostat probably springs to mind. Raise the temperature in summer, for example, and voila! You have a lower bill. While it’s true that only a few degrees difference can have a huge impact on your bill, there are numerous other ways to conserve resources. A thorough home energy audit can set you on the path to lower electricity bills and a smaller carbon footprint. You might even save so much you can afford to indulge in chilly indoor temps this summer.
How to Conduct Your Own Home Energy Audit
While a professional audit will always yield the most precise results, a preliminary DIY audit can provide useful insights that will help you save money by limiting energy waste.
Check for Air Leaks
This is a crucial step in the energy audit process. Air leaks force your HVAC system to work harder by admitting temperatures that compete with your climate control system. Some leaks, such as drafty windows, may be obvious, but stealthier leaks require their own detection and measurement tests.
Professional technicians rely on blower doors – powerful fans used to depressurize the home – in order to identify leaks. If you, like most people, don’t have blower doors in your garage, you can still perform a basic building pressurization test using nothing more than an incense stick and a roll of masking tape. The goal here is to increase air penetration through cracks and crevices, thereby making the leaks easier to detect. To perform your own airtightness test, complete the following steps (preferably on a cool, windy day):
- Close all external doors, fireplace dampers, operable windows, and skylights.
- Turn off all heat sources – such as fireplaces, furnaces, and gas water heaters.
- Turn on all exhaust fans in the house – think kitchen, bathrooms, and laundry room.
- First, check the fireplace for leaks. Soot and a foul smell will signal leaks around the fireplace damper. If you identify damper leaks, immediately turn off the exhaust fans and fix the damper before proceeding with your audit.
- Once you’ve resolved any damper leaks, turn the exhaust fans back on. Use a lit incense stick to check for leaks around all external openings – doors, windows, electrical outlets, light switches, light fixtures, access doors, and at the top, bottom, and corners of walls. If you notice the smoke being pulled in a certain direction, you’ve located a leak. Mark the site of the air leak with a piece of masking tape so you can return later to apply caulk, weatherstripping, or foam inserts, depending on the type of opening.
Look for Insulation Inefficiencies
Faulty insulation is one of the most common reasons for energy inefficiency in the home. Insulation standards have become increasingly stringent over time, especially as energy becomes more scarce and prices increase. The original insulation in older homes is therefore unlikely to meet today’s standards. Only a thermographic inspection can tell you exactly how much of your wall is insulated, but there are some DIY tests you can do to assess the adequacy of your home’s insulation.
Start with an inspection of attic spaces. If your attic hatch is located above an air-conditioned space, ensure the hatch is at least as heavily insulated as the attic, weather-stripped, and capable of closing tightly. Next, check to see whether openings in pipes, ductwork, and chimneys are properly sealed. You can seal gaps with expanding foam caulk or other permanent sealants. Just be sure to select a non-combustible sealant when filling gaps around heat-producing elements like chimneys. It’s also important to ensure that your attic floor is covered with at least the recommended amount of insulation.
Determining the sufficiency of your walls’ insulation is a bit trickier without thermographic equipment. Try these methods to perform your own insulation inspection:
- Select an exterior wall and turn off the circuit breaker, or unscrew the fuses for any outlets in the wall. Make sure the electricity is fully disconnected by plugging in a lamp or other small appliance.
- Remove an outlet cover and gently probe into the wall with a screwdriver or plastic crotchet hook. Slight resistance indicates the presence of insulation, but not the extent of coverage.
To ascertain if your wall is completely filled with insulation material, enlist a professional energy-efficiency technician to perform a thermographic inspection.
Make Sure Your Lighting Is Energy-Efficient
According to Energy.gov¹, lighting accounts for 15% of the average home’s electricity usage. Switching from incandescent to LED bulbs is one of the simplest ways to reduce your energy bill. You can also purchase energy-efficient lamps and WiFi-enabled home devices that allow you to further limit your lighting-based energy usage by way of controls such as sensors, dimmers, and timers.
Inspect Your HVAC System
Heating and cooling equipment should be inspected annually to ensure optimum efficiency. Be sure to replace air conditioner and forced-air furnace filters during your energy audit, and take a moment to consider how often you usually perform this task. Filters should be replaced every one to two months for ideal air quality and energy efficiency. If your air conditioning unit is over 15 years old, it may be time to replace the system altogether. Newer energy-efficient units can significantly reduce energy consumption.
It’s also important to check your ductwork for dirt streaks every few years, and your energy audit offers the perfect opportunity to do so. Streaks of dirt indicate air leaks, which can be sealed with a duct mastic. Ensure that your ductwork, especially ducts and pipes in uninsulated areas, is properly insulated with a minimum R-Value of 6.
Estimate the Energy Usage of Your Appliances and Electronics
Older, inefficient appliances and electronics can significantly increase your energy usage. Take an inventory of your devices and estimate their energy costs². The up-front price of a new refrigerator or washer and dryer may seem daunting, but it will save you money in the long term.
As part of your energy audit, take a moment to consider habitual household behaviors. Do you unplug electronics when they’re not in use? Doing so will prevent energy loss through “vampire electricity” or phantom load, both terms used to describe electricity wasted through inactive devices. A simple way to eliminate vampire electricity is to install WiFi-connected power strips that can be managed from your smartphone. These devices make it easier to turn off larger appliances like your television and desktop computer without regularly moving heavy furniture to access the outlets.
When in Doubt, Hire a Professional
A DIY energy audit is a great way to begin assessing your home’s energy efficiency. If you’re left with knowledge gaps post-inspection, consider hiring a professional auditor. They can help you assess harder-to-reach areas like insulated walls and attics.