Home Energy Audit

Home energy auditing is a process whereby the home owner or a professional will inspect the energy consumption and efficiency of a home. The definition of audit is to examine carefully for accuracy with the intent of verification. In the case of a home energy audit, there are three main areas that will be inspected as follows to verify how much energy is needed verses how much is being used and also ways to reduce how much is needed over time:

1. Heat and Cold Loss
2. Electrical Consumption
3. Resident Behavior

A professional home energy audit usually begins with a qualitative analysis. The auditor will speak with the resident about their daily habits and understand the needs and constraints put onto the house. This type of observation might include the following investigation:

• When is the house being used
• What are the ambient temperature settings
• What are the high and low temperatures set at
• How much energy is normally used to run the house, ie. electrical and gas bills
  
• What technology and building materials are in place on the structure
  

Once a general understanding of the house and it's occupants has been achieved it is possible to use tools to test the efficiency of the house and then recommend upgrades where necessary. The tools and processes that many energy auditors use include:

• Blower Door Test - a special fan called a "calibrated door" is fitted to an exterior door of the house in combination with smoke pencils and other tools to suck air out of the house and determine how air tight it is. When determining how much leakage a house has it is important to remember that some leakage, in the right areas, is good. Without the ability to breathe, the house may become moldy or experience indoor pollution. More information on the blower door test is available here
  
• Thermographic Scan - this technique can be used to capture heat signatures on the interior or exterior of a home and may lead to recommendations of more insulation or insulation repairs. Usually interior heat signatures are easier to read since there is less air disturbance inside of a home. This type of scan may be useful in combination with the blower door test and is recommended when there are extreme differences between the indoor and outdoor temperatures ie. the winter months. This type of test is highly recommended before buying a house and more information on thermographic scans and the types of tools used in a scan, such as a spot radiometers and thermal imaging cameras, can be found here
• PFT Air Infiltration Measurement - PFT stands for perfluorocarbon tracer gas which is a harmless, odorless gas that is transmitted and received with special instrumentation designed by the Brookhaven National Laboratory to detect changes in temperature and air leakage in a room. In contrast to the blower door test, which puts stresses on a house to determine the quality of its air tightness, the PFT test measures air tightness over time as ocupants actually go about their daily routines including the influence of seasonality and weather. This technique can also be used to determine exposure to harmful substances and pollution such as radon. More on this topic can be found here

Aside from the professional techniques and tools used to conduct a home energy audit there are several do it yourself or "DIY" techniques that can be used to effectively and affordably reduce energy consumption up to 30% per year as follows:

• Identify and repair gaps and leaks in the following areas of your house:
•  walls, floorboards, electrical outlets
• windows, and mailbox slots
• electrical outlets, internet and cable outlets, and lights - recessed ceiling lighting is one of the leading heat loss sources. As heat rises it easily escapes through these poorly sealed light ducts
  
• You may already know of a draft or a chilly or cold area in your house which can be repaired using caulk or foam insulation.
• Weather stripping around doors and garages often gets overlooked but is very easy to repair and replace using rubber door jams or foam.
• Fireplaces, attics and window mounted fans and air conditioners are other sources of air leakage.
• holes where pipes from sinks and other utilities go into your walls
• exterior foundation lines, chimneys, and corners where two materials meet such as brick and wood
  
• Consider replacing old warn out air leak sources with the following technology
• Use caulk to reseal old cracked areas and touch up on areas that may have been overlooked
• Purchase new double paned windows or put clear plastic sheets over existing windows and walls for a more affordable approach
• Jiggle your doors and windows and look for light streaming through to determine if you need to reposition them or add foam strips
• Conduct a do it yourself blower door pressurization test by closing all of your homes doors, windows, fireplaces, and other outlets and then turn on your bathroom and kitchen oven fan. Now explore your house using a smoke producing device such as incense or a punk from the fourth of July celebrations and watch how the smoke is influenced as you hold it near different areas. Always be careful with this technique as not to start a fire, one alternative is to carry a damp wash cloth in one hand and then wet the surface of your other. Hold your damp hand near possible air flow leaks and sense air coming in from outside. While doing this test be wary of sucking smoke or other pollutants into your house that may compete for oxygen and cause you to suffocate. Also recognize that your heater, stove, or furnace may be burning oxygen and if you have no fresh air coming in you could run out. Understand the environment that your house is in and take the proper precautions including contacting a local energy auditing professional.
• Add more insulation to your attic or foundation and consider using environmentally friendly cotton "blue jeans" insulation that is easier to work with, natural, and sustainable. Insulation is the most cost effective way for most home owners to reduce energy use - many homes were built to meet minimum requirements for their time and as prices for energy continue to rise one the easiest ways to conserve heat or cool in your house is to not use it in the first place and insulation helps you keep temperatures more stable. Additionally, if you have an attic you will want to seal it the same way you have sealed your doors and windows.
  
  Dig under your attic insulation and look for a vapor barrier which is usually plastic, tar paper, or fiberglass. This barrier prevents moisture from leaking down into the house which can cause structural damage. In many cases, simply adding an additional layer of new insulation to pre-existing layers can make a dramatic difference in the way your home stores energy, especially heat.
  
  In order to test your house wall insulation it is recommended that you use a professional to conduct thermographic testing as discussed above. There are many electrical hazards in walls so always be careful when investigating these sources.
  
  One other great source for improving insulation is in a basement. this will keep the temperature between the main living floor and potentially unused spaces from blending together and wasting energy. When adding insulation to walls, ceilings, attics, or basements consider using too much rathar than too little and follow the R-Value guide which says that a minimum level of insulation has an R-Value of 25 which is equal to the insulation properties of 25 feet of earth.
• Change filters and clean electrical devices (at least once per year) including your forced air furnace or heater. It is recommended for most of these devices to replace filters every two months which may be long past due in your household and could be causing unnecessary strain on the system which takes energy.
• Replace old systems that have been in place for more than 15 years. You may be amazed at how your electrical bill changes. This is especially true of old refrigerators and furnaces.
  
• Use duct tape to reseal your ducts and use insulation to make them more efficient. If you see streaks of dirt inside or outside of your ducts you probably need to clean the filter and make the duct tighter because hot or cold air is leaking out. when adding insulation around ducts aim for an R Value of six or seven.
• Replace old light bulbs. The average US house uses ~10% of it's electricity to power lighting which can be improved significantly by using CFL (Compact Fluorescent Light bulbs) which are now available in different color tones and with dimming functionality. CFL's are four times more efficient than regular bulbs and last up to ten times longer on average! This improvement in technology is also helped by government rebates and incentives to change out old lights and even replace lighting fixtures. LED lights are also gaining in popularity and may soon replace CFL's in certain lighting applications. Already LED's are being used for car headlights and road signals, they offer increased durability and brigtness but are cost prohibitive at this time.
  

More information will be added to this guide on an ongoing basis but we welcome user feedback and tips from our readers who may have discovered other unique ways to conserve electricity.