Most people are, understandably, not familiar with what a home energy assessment is. You get your bills and you pay them. You try to make sure your family members turn off lights when they leave a room, make sure no one fiddles with the thermostat, and by all means keep the doors shut, but your bills are still high. Could there be other issues causing your high bills?
Who is This Guy?
Building science is a growing field of study that owes a lot of credit to the scientific achievements of Joseph Fourier, a French mathematician and physicist who studied the movement of heat. One of the most important relationships Fourier was able to describe is the movement of heat across a material, or Fourier’s Law, which can be expressed mathematically as:
Q = U x A x DT x t
- Q = the rate of heat movement through a material.
- U = represents a materials resistance to heat flow. i.e. the more insulation you have in your attic the slower heat moves through it.
- A = the area of a material. The more surface area you have the more heat can move through a material. This is why the way a house is oriented can make a huge impact on how energy efficient a house is.
- DT = the difference in temperature on both sides of a material. The bigger the difference in temperature the faster heat moves through it. This is why your bills are highest on the hottest and coldest days of the year. Those are the days where the difference between the temperature inside and the temperature outside is the greatest.
- t = represents time. The longer a material exposed to high temperature differentials the more heat moves.
The movement of heat is fundamental to understanding how a home uses energy, how a home acts as a system, and also how to make your home more energy efficient.
Fun Fact: Fourier is also widely recognized at the first person to suggest that the Earth’s atmosphere acts as an insulator, or what is now known as the greenhouse effect.
What’s Behind the Red Door?
The blower door test is one of the main diagnostic tools that a home energy expert has to determine where heat loss is occurring. The blower door uses a pressure gauge and fan that can pressurize or depressurize a home to figure out where and how much air is coming in and out of a home. By depressurizing a home you can exaggerate the amount of air coming through a bypass so you can actually feel the movement of air to know where the house needs to be sealed.
Surprisingly, most homes typically have the largest leaks through the attic and through the crawlspace. This is because that is where the largest openings typically are.
Most people assume that most of the air leakage is coming through their doors and windows. This is a common misconception. The confusion is because you can feel heat movement through a door or window when it is really hot or really cold outside, because of Fourier’s Law, which is not the same thing as air movement. Air does not move through a solid object. However, heat does; and heat moves through doors and windows typically faster than through the walls next to them. There can be problems with air leakage around windows and doors, but it is usually not as big of an issue as larger bypasses that are typically found in attics and crawlspaces.
Newer homes also need to be tested to make sure they are not too tight. Homes need to have a certain amount of fresh air exchanges per hour. This is because tight homes can create poor indoor air quality issues such as mold, mildew, and high concentrations of VOCs, or volatile organic compounds that can impact your health.
Are My Ducts Working Efficiently?
Home energy experts will also test your ductwork to see how much conditioned air is leaking out into unconditioned space through duct leakage. Using pressure diagnostics, home energy experts can determine not only the total amount of duct leakage, typically around 30% for Arkansas homes, but isolate where the leakage is coming from.
Duct leakage can be one of the biggest drivers of high utility bills, and it is usually something that people are unaware of. Properly sealing your ductwork can make your home easier to heat and cool, make you more comfortable throughout your home, and save you money. The last thing anyone wants to do is pay to heat or cool the outside.
Do I Have Enough Insulation?
When is the last time you looked in your attic? Ceiling insulation is a critical factor in reducing heat movement. If you can see the wooden joists in your ceiling, you do not have enough insulation. The Department of Energy recommends that Arkansas homes have an R-38 value for their ceiling insulation. This is about 12 to 14 inches depending on the type of blown insulation used.
The main thing you want is to have a continuous layer of insulation throughout the ceiling. If you do not have insulation over your wooden joists, this can create a thermal break allowing heat to move quickly between your attic and conditioned space, which causes your heat and air to have to work harder to maintain your thermostat set point causing utility bills to increase.
Is My Heating and Air Conditioning Working Like it is Supposed To?
Heating and cooling represents close to half of your utility bill. Making sure they are operating efficiently is critical to keeping you comfortable and keeping your bills low. Servicing both your heat and air conditioner annually is a great way to keep your heat and air units as efficient as possible and extend their lifespan.
When it is time to replace your heat and air system, it is important to know you are replacing the unit with the right size for your home and you are taking advantage of some of the more advanced features that newer units offer, like high efficiency heating and cooling, humidity controls, and advanced thermostat controls.
How Do Lights and Appliances Affect My Bills?
Arkansans spend around 43% of their utility bills on lights and appliances. These are items that are typically used every day all year round, so making them more efficient can save you money in the long run. Switching to Energy Star high efficiency appliances and upgrading your old light bulbs to the newer longer lasting energy-saving LED lighting is one of the quickest and easiest ways to start saving money on your utility bills immediately.
Is My Home Safe?
Carbon monoxide is odorless, colorless, and tasteless, which is why many call it the “silent killer.” A home energy expert carries equipment to measure the amount of carbon monoxide in your home and can point out potential indoor air quality issues that can create hazards you may have been previously unaware of. Home energy experts can also diagnose homes that may have moisture issues as well as identify solutions to improve your home’s indoor air quality, making your home safer for your family.
Why am I Uncomfortable in My Home?
Do you have a room in your house that is always uncomfortable? Home energy experts can provide important diagnostic testing to determine why you are uncomfortable. Discomfort can be the result of high humidity in the home, lack of airflow to specific rooms, poor duct design, over or undersized heat and air units, and poorly insulated spaces. Many people don’t even realize how uncomfortable they were until they have had their home improved by having simple home energy improvements done on their home.
What Can I Do?
The first step is to have a home energy assessment done to determine what opportunities your home has to improve in efficiency and increase your comfort levels.
Call 501-414-8094 or sign up online to have a home energy assessment done on your home.
– Seth Baldy, BPI-Building Analyst