Should I have a thermographic energy audit? Can a homeowner check on this themselves? Properly insulating the attic is a first step to energy efficiency.
I was speaking to a group of employees at this firm yesterday about looking at their home to improve energy and water efficiency. A few questions focused on insulation and sealing, but one question concerning an energy audit caught my attention. He wanted to know the cost of having a thermographic examination of his home. If we are looking at insulation in your walls, then maybe this is the best route, but I feel that homeowners can save money if they look at a few items first. This self energy audit may begin in the attic. Builders may not and are not required to fully insulate the attic, but from the standpoint of energy efficiency, any small gap in insulation is a huge problem. Part of the reason for my talk was to give people an understanding of their home, so they could conduct their own energy audit.
If I were to begin my own energy audit, I would start with my utility bills. Do not look at what you spend; look at how much electricity you are using. Prices fluctuate , so they are not a good gage. After collecting my bills for a year, I would go to the site of the Lawrence Berkeley National Laboratory’s Home Energy Saver program. This will give you ideas for your home, and how you should proceed. To understand your utility bills, you should write a journal of what happened each month to explain the power usage. For example, when my wife was home on maternity leave one year, my electricity usage went up in months were the trend was normally down. Some things may seem obvious (summer in Houston has electricity usage going up), but have an explanation anyway (one summer my son is home, while the next summer he is traveling in Mexico), because you may discover a few factors that effect how your home is used.
You do not want gaps in your insulation. The photograph shows a home with a bit of an unusual design. A first floor office area has an attic space which leads up to the main attic above the second floor. The picture was taken from the upper attic looking down to the space above the office, where we find no insulation. What may have happened in this case is the insulation was blown in by a contractor who was standing on the platform by the attic entrance. He made a sweep of the main attic, but he did not realize that the opening in the corner was leading to another space which needed his attention. I admit walking an attic can be tricky, which may be the reason why some home inspectors have argued against going around that space. If you are careful to find a foothold on a piece of lumber, you will be safe. I prefer going in my socks, since I can feel under the insulation better. Check to see that all areas have insulation (shafts in two story homes often exist to bring down ducts, but these shafts are not insulated). You also want insulation over patios and garages, since they effect the attic. Then ensure that all of the joists (lumber laying horizontally over your ceilings) are covered by insulation. This prevents thermal bridging. You do not want insulation covering recessed lights that are not rated to have insulation against their housing (read the label on the housing). While in the attic, check that your ducts do not have holes, and you should check that they are well insulated (older metal tube ducts may not have much insulation on them). For the best efficiency find out what the best R-value for the insulation in your area should be. For example, in Houston this is an R-48, but most people have an R-32 in this city.
Next, we will look at penetrations to your building envelope. Any item sticking out of your roof or coming out of your wall is a penetration. A penetration can also be any opening, like a door or window. A penetration that we do not want to seal is the ventilation system of the attic. Having air flow through the attic reduces the heat and decreases the moisture in this space. When in the attic, we want to check that the soffit vents are not blocked. Another opening that we do not want to block is the method for the moisture to leave our exterior wall. On a brick wall, these are the weepholes at the bottom course of bricks. For a plank siding, the last course has a gap for moisture to drop down. On stucco, there is an opening at the base for moisture to exit the wall. Other areas will require sealing. This is the caulking around windows and doors. Caulk can separate from the wall over time, or the caulk could wear out, so every so often you will need new caulk. On newer style windows, you may see two holes at the base. These are for moisture to escape from the base of the window frame. Check the interior of the windows as well. I often find that there are gaps between the window frame and the interior wall at the top of the frame. For doors and windows, we want to make sure that they close fully. If they do not close, they are not energy efficient. If we see light around and exterior door, we need weatherstripping. Purchase stripping that fits the gap (sometimes people think bigger is better, but we want the door or window to shut).
Two penetrations require a little more than sealing. Fireplaces with their chimneys are not good for Houston. If your damper is not closed, or if you have a stopper to ensure that your damper does not close fully, you will be letting your conditioned air escape your tight building envelope. More than half the chimneys that I investigate have a problem with the damper. There are sealed gas burning fireplaces that do not have this issue. The other penetration is your range hood vent. This vent should go to the exterior (some units are designed to recirculate the air). The purpose of the range hood vent is to rid the house of moisture (which will not happen with a recirculating type). In older homes but also some newer homes, this vents out through the roof. When this is the case, like the open chimney, you have an opening where conditioned air can escape. The range hood vents going out of the side of the home frequently have the vents that have louvers over the exit. This does act a bit like a closed damper.
Once we have sealed our building envelope, there are a few items to examine to improve efficiency. You should have a programmable thermostat. If you do not, you should obtain such a thermostat. Check the program. For example, during summer months, you want the house to be warmer when fewer people are home (or no one), and cooler when the home is occupied with everyone. You do not want wide temperature swings though. Keep the temperatures within five degrees Fahrenheit. Have ceiling fans in each room or commonly used rooms. We feel comfort with air movement; that is why many of us run our cooling system all of the time, we want the air flow. Having the ceiling fan push air down in the summer, and up in the winter, helps create an air flow that mixes the air to a consistent temperature, while we feel good, because of the air flow. A little more advanced is planning out a system that controls how much air is going to each room. By having less conditioned air go to a room that we hardly use, we can have more conditioned air to rooms that are more occupied.
Moving on with our audit, we will want to look at our appliances and gadgets. Most modern electronic items will constantly draw power. Having a power strip that shuts down power to items like a television when they are not in use is the best for energy efficiency. Not leaving chargers plugged into the wall all of the time (any cord with a box at the end will continually draw power from the outlet). Having all of our light bulbs changed to compact fluorescent lights (CFLs) or LEDs (check that you are getting the proper lighting level- lumens- from the bulbs). Many people change out a few bulbs to efficient ones, but they forget to do the entire house. After we have done this, we will examine our appliances. Any appliance that is older than ten years could be an energy drain. The big trend now is to make appliances that are energy efficient. Updating your refrigerator, washers, heaters, and other appliances may reduce your utility bill significantly.
The last part of your audit involves exploring your lifestyle. Many people who have an energy efficient home do not see any savings in their utility bills. The home may be designed well, but our habits could be causing us to use more energy. Try using natural light instead of turning on a fixture. Do you need the television on when working at your desk? Are we using a desktop computer where a more efficient laptop would suffice? By examining our lifestyle, we may find that we are using power when we do not need to be using energy. My wife and I make it a point that the family eats together. This is great for the family, but you may not realize that this is an energy saving move as well. If each person is eating in their own space, we may all be using lights, watching television, or something else. We also have family time after dinner. We go out to the yard with the children to play, instead of everyone going off into their individual corners. Some habits are simpler, like leaving a porch light on, so we do not have to bother turning it on and off.
Begin walking around your own home, and you will be surprised at what you find. However, first know where you are, so look at the utility bills. Did you know that you pay different amounts for the same amount of electricity, depending on the time of day. Running appliances like the dishwasher later at night can save you money. Understanding the utility bills, will help you see your pattern.