The EnerGuide Rating System was developed by Natural Resources Canada as a tool to rate a home’s energy performance. The EnerGuide scale ranges from 0 to 100 and takes into account millions of houses across Canada, with various ages.Many factors can affect the rating. Even if two houses appear identical, their ratings can be different if they have different levels of insulation, types of heating equipment,etc. For many older houses, a rating of 65 or higher is considered quite an achievement. New houses usually receive a rating of 65 or higher, because of improvements in building standards and practices over the years. Few houses achieve a rating of 80 or higher, and those that do represent the most energy-efficient houses on the market. Therefore, the EnerGuide rating scale shown below ranges from 65 to 100. All new homes built according to the Ontario Building Code (2012) must achieve an 80 on the EnerGuide scale.Energy Star qualified new homes are designed and built to save energy and provide comfort.
They are also built airtight, which helps avoid air leakage problems that cause energy waste and higher energy bills. Compared to a typical home, an Energy Star qualified home is 20% more energy-efficient and must achieve an 83 on the EnerGuide scale.R-2000 certified new homes are built to strict air tightness requirements and have the right amount of ventilation. The fresh-air ventilation device improves air quality. Special attention is given to design in order to optimize home comfort. Compared to a typical home, an R-2000 home is 50% more energy-efficient and must achieve at least an 86 on the EnerGuide scale.Net Zero homes are airtight, well insulated, sufficiently ventilated and require no purchased energy on an annual basis. It must achieve 100 on the EnerGuide scale. The R in R-Value stands for "resistance". When referring to insulation, this resistance is for heat.Insulation resists the flow of heat through a home's walls, floors and ceilings. This resistance slows heat down and keeps it inside in the winter and outside in the summer, making the home more comfortable and energy efficient.
Therefore, the higher the R-value, the greater the insulating power. Below is a comparison of a home built to the Ontario Building Code compared to an Energy Star rated home by Reid's Heritage Homes. The improvements are impressive. For Net Zero homes, we have increased the R-value even further to provide the best insulated and air tight home possible. This results in more comfort for the homeowner, reduced noise from the outside, and increased savings on energy bills. A home's air tightness is typically expressed in air changes per hour (ACH) at an indoor-outdoor pressure difference of 50 pascals (Pa). The air tightness of a home can be measured with specialized equipment commonly known as a “blower door.” For a Net Zero home, the targeted air change rate may be 1.0 ACH or less. In comparison, a typical code-built home would test at 2.5 to 3.5 air changes per hour or higher.A blower door test was conducted on our Net Zero Discovery Home and the results were 1.36 ACH at the pre-drywall stage and an astounding 1.1 ACH once completed!
This is one air tight home! This result also means savings on gas and electricity for the homeowner.Read about the savingsSee process and results at a modern log home Sealing and insulating the "envelope" or "shell" of your home - its outer walls, ceiling, windows, doors, and floors - is often the most-cost effective way to improve energy efficiency and comfort. The US Environmental Protection Agency (EPA) ENERGY STAR program estimates that a knowledgeable homeowner or skilled contractor can save up to 20 percent on heating and cooling costs (or up to 10 percent on the total annual energy bill) by sealing and insulating a home. Whether your home is a traditional stick frame house, manufactured home, or custom log cabin, single story or multistory, air leaks within your home are a form of energy loss and need to be eliminated to minimize energy losses and reduce utility costs. Utilizing modern tools such as thermal imaging, blower door technology, and duct testing can help the homeowner and energy utilities identify key energy losses and repair components of the structure, while conserving overall energy within the home.
This article will primarily discuss thermal imaging used in conjunction with blower door technology, emphasizing the importance of sealing and insulating your home. However, heating, ventilating, and air conditioning (HVAC) duct losses can contribute to large energy losses, as well. Thus, duct testing and repair should not be ignored, but are not discussed in this article. Note that the pictures in this article are of a modern log home, but the principles discussed here apply to all types of residential and commercial construction. Thermal imaging cameras detect energy in the infrared range of the electromagnetic spectrum (roughly 7000 - 14,000 nanometers or 7 - 14 µm) and produce images of that energy, called thermograms or thermal images. The Fluke Ti-32, which was used for this article, has an infrared spectral band sensitivity of 7.5 μm to 14 μm (long wave).Outside the home, the orange and red areas show hot air leaking to the outside.Cooler air (dark blue and black) infiltrating between the logs of the wall.
Homeowner points out cool air infiltration.Setting up the blower door device.Using a thermal imager with blower door temporarily installed, to look for air exfiltration. Be careful to understand the impact of solar loading. Since infrared energy is emitted by all objects above absolute zero, thermography makes it possible to see energy losses in a home without visible illumination. The amount of energy emitted from the home increases with temperature; therefore, thermography allows you to see variations in temperature in a home. When viewed through a thermal imaging camera, warm objects or heat leaking out of, or into, a house stand out well against cooler backgrounds; thus energy losses or gains from the home become easily visible, day or night, winter or summer. Thermal imaging cameras reveal temperature changes and differences in real time that are invisible to the naked eye. This technology allows testing for energy losses without requiring contact with or damage to the building.
Infrared cameras are therefore very suitable for home inspections, as no exterior or interior finishes need to be taken down and you can inspect large areas in a short time. Infrared thermography has become one of the most trusted and common residential inspection tools available. The real-time picture of a thermal imaging camera shows instant and documentable areas of potential energy loss. Notice in Figure 4 that the cold air is falling into the room and hot air is rising up onto the ceiling. What's to be gained from a thermal imaging inspection? Homeowners, residential property managers, real estate agents, insurance companies, and contractors all need residential inspection services, and will be best served by a thermal imaging inspection. Homeowners wish to preserve and protect their investment, as well as lower energy costs. Property management firms, or those who own large real estate units, benefit from being apprised early of insect infestations, moisture issues, and mechanical or electrical problems.
Additionally, a property owner with a large building, or a row-housing complex with a shared front façade or roof, can use the information from an infrared inspection to make economically smart decisions. Many times the homeowner or the general contractor who built the home is surprised to see the air leaking or energy losses. In Figure 5 a homeowner points out the air leakage penetrating the home. Air leakage testing using the blower door Most state energy codes require air leakage testing for all new houses. The test must be performed using a blower door device, which consists of a large fan, a door-panel system, and a manometer (pressure gauge) to read house and fan pressures. All penetrations in the building envelope must be sealed, including those for utilities, plumbing, electrical, ventilation, and combustion appliances. The air leakage test is only required (in most states) for new construction. However, it is a good recommendation to have this test done when an energy inspector is evaluating your home with a thermal imager, because it will help to pinpoint specific air leaks and problems in the structure.
A blower door has a frame and shroud that fit inside a doorframe. Mounted in each blower door is a variable-speed fan that allows it to induce pressure on the inside of a dwelling. Instrumentation that accompanies a blower door includes pressure gauges with which a technician can measure the flow of air through the fan as well as the pressure differential between the living space and the outdoors. With a blower door in operation, a technician armed with a thermal imager and a pressure gauge (to verify the pressure differential in various parts of a dwelling) can find areas that contribute to the loss of conditioned air (heated in the winter and cooled in the summer) by convection. What does this mean to you? In construction projects, the building contractor who uses thermal imaging technology will have an advantage by being able to identify clear problems and prove that repairs have been completed correctly. Insulation, restoration, and repair costs can be minimized by conducting an infrared inspection before valuations, transactions, or major system upgrades.
A thermal imaging camera detects small temperature differences and can be used indoors and outdoors, and on wood, concrete, drywall, and electrical wiring. This technology can be used in the following applications: Infrared inspections were seen in the past as affordable solely for large commercial organizations, but now thermal imagers are more available and lower in price. Homeowners want to use the technology to find sources of energy losses: air leaks, insufficient insulation, and moisture problems. Over time, correction of these problems will save the homeowner a significant amount of money.Log home after it was sealed and caulked. Remedies for air leaks in a residence You can hire a contractor who is certified with special diagnostic tools, such as thermal imagers and blower doors, to pinpoint and seal the hidden air leaks in your home. Figure 8 shows the log home with chinking after the house was sealed. Sealing and chinking this log home was very effective, but the contractor failed to seal the cracks in the log walls, and additional sealing will be required to completely minimize energy losses.