Arizona Consumer’s Guide to Buying a Solar Electric System

Part 1 of Arizona Consumer’s Guide to Buying a Solar Electric System. Are you thinking about buying a PV system for your home or business? If so, this series will provide basic information that you need to know. Consumer’s in Arizona are showing increased interest in solar electric systems for their homes and businesses. These […]


Weatherize Your Home: Assessment

Part 1 of Weatherize Your Home. Warmed or air-conditioned air mixes with outside air through gaps in your home’s thermal envelope—exterior walls, windows, doors, the roof, and floors. Such air leaks can waste large amounts of energy. Most experts agree that caulking and weather stripping any gaps will pay for itself within one year in […]


Safety and Health Concerns (Loose-fill insulation)

Part 7 of Loose-Fill Insulation. Safety Guidelines Insulation blown into your ceiling cavities should cover the top plate of the wall, but be sure the eave vents are not covered. These vents provide necessary ventilation to your attic, and covering them could result in severe moisture problems. Electrical devices and recessed lights (except “IC-rated” fixtures) […]


Installation Quality Control (Loose-fill insulations)

Part 6 of Loose-Fill Insulation. Voids and Gaps To ensure a quality installation, there are several things to watch out for when installing loose-fill insulation—whether you do the job yourself or hire a professional. You may create undesirable voids or gaps if you install the insulation at too low a density or if you do […]


Cost of Loose-Fill Insulations

Part 5 of Loose-Fill Insulation. At the time this publication was written, the average loose-fill insulation cost per R-value per square foot was about 0.8 cents for cellulose and rock wool and 1.1 cents for fiberglass. These prices were for materials only. The average installed price per R-value per square foot was about 1.2 cents […]


Before You Install Insulation

Part 4 of Loose-Fill Insulation. Upgrading or Repairing Other Building Components There are other home weatherizing and sealing measures to complete before you undertake any insulation project. Atight, well-sealed home is more energy efficient and needs less insulation to keep you and your family comfortable. Tests have shown that far more cold air infiltration and […]


Comparative Performance of Loose-Fill Insulations

Part 3 of Loose-Fill Insulation. Insulation materials are compared on the basis of their R-values per unit of thickness, density per unit of volume, and weight per unit of area. There are several performance characteristics to consider when selecting an insulation material. Among the most important to compare are insulating capacity, weight, convective heat loss, […]


Primary Applications of Loose-Fill Insulations

Part 2 of Loose-Fill Insulation. Loose-fill insulations are well suited for places where it is difficult to install other types of insulation, such as irregularly shaped areas, around obstructions (such as plumbing stacks), and in hard-to-reach places. They can be installed in either enclosed cavities such as walls or unenclosed spaces such as attics. Blown-in […]


Loose-Fill Insulations

Part 1 of Loose-Fill Insulation. Whether you are increasing the insulation levels in your current home or selecting insulation for a new home, choosing the right insulation material can be challenging. Fibrous loose-fill insulations such as cellulose, fiberglass, and rock wool are options you may wish to consider. This publication will introduce you to these […]


Sunspace Components

Part 4 of Sunspaces. Glazing Glazing is clear or translucent materials that allow sunlight to penetrate and warm the room. Glass is the most common glazing material, and many sunspace developers choose glass for its durability, clarity, and appearance. But plastic glitter may be cheaper, stronger, lighter and easier to work with, making them popular […]


Sunspace Design Guidelines

Part 3 of Sunspaces. Passive solar systems structures are conceptually simple. However sunspace designers and builders must pay close attention to details to ensure maximum performance and reliability of the structure. Computer software is now available to help design and establish criteria for specific projects such as passive solar sunspaces. This software makes it relatively […]


Sunspaces: Design Considerations for various functions

Part 2 of Sunspaces. Sunspaces serve three main functions: they are a source of auxiliary heat, they provide space to grow plants and have fun living areas. The design considerations for these features are very different, and although it is possible to build a sunspace that will serve all three functions, some compromises will be […]


Sunspace Basics: Introduction

Part 1 of Sunspaces. Everyone living in a home with a sunroom or sunspace will tell you that it is the most comfortable room in the house. Many times the homeowner only complaint is that the sunspace should be bigger. Although aesthetics often drive the decision to add a sunspace to a home design, sunspaces […]


Knee Walls

Part 2 of Ceilings and Attics. Knee walls are vertical walls with attic space directly behind them. They are often found in houses with finished attics and dormer windows, such as in story-and-a-half designs. One approach to constructing an energy-efficient knee wall is to first air seal the knee wall using conventional techniques (i.e., seal […]


Energy-Efficient Cathedral Ceilings

Part 1 of Ceilings and Attics. Cathedral ceilings must provide space between the roof deck and ceiling for adequate insulation and ventilation. For most areas of the U.S., the 1995 MEC recommends R-25 to R-38 insulation in a cathedral ceiling. This can be achieved through the use of truss joists, scissor truss framing, or sufficiently […]


Attic Insulation Techniques

Loose-fill or batt insulation is typically installed in an attic. Although installation costs may vary, blowing loose-fill attic insulation—fiberglass, rock wool, or cellulose—is usually less expensive than installing batts and provides better coverage. STEPS FOR INSTALLING LOOSE–FILL AND BATT INSULATION Seal all attic-to-home air leaks, especially chases, dropped ceilings, wiring and plumbing penetrations, light fixtures, […]


BENEFITS OF CEILING INSULATION

Insulating ceilings is one of the most cost-effective energy efficiency measures. In addition to reducing heat loss in the winter and heat gains in the summer, ceiling insulation improves comfort by bringing ceiling temperatures closer to room temperatures and providing an even temperature distribution through- out the house. When planning and managing ceiling insulation projects, […]


Installation and Location of Air Conditioners

Part 5 of Energy-Efficient Air Conditioning. If your air conditioner is installed correctly, or if major installation problems are found and fixed, it will perform efficiently for years with only minor routine maintenance. However, many air conditioners are not installed correctly. As an unfortunate result, modern energy-efficient air conditioners can perform almost as poorly as […]


Installing an Insulation Blanket on an Electric Water Heater

Part 5 of Energy-Efficient Water Heating. Note: Installation is more difficult on gas- and oil-fired heaters. Ask your local furnace installer for instructions. 1. Cut the tank top insulation to fit around the piping in the top of the tank. Tape the cut section closed after the top has been installed. 2. Fold the corners […]


Increasing Water-Heating System Efficiency

Part 3 of Energy-Efficient Water Heating. Reducing hot-water usage is primarily a matter of common sense and exerting a little extra effort to not be wasteful. Once you have applied a few simple, low-cost measures for reducing hot-water consumption, you may want to consider water-heating system improvements if you wish to further reduce your energy […]


Resources: Elements of an Energy-Efficient House

Part 8 of Elements of an Energy-Efficient House. The following are sources of additional information on energy-efficient houses: The Energy Efficiency and Renewable Energy Clearinghouse (EREC) P.O. Box 3048 Merrifield, VA22116 1-800-DOE-EREC (1-800-363-3732) EREC provides free general and technical information to the public on many topics and technologies pertaining to energy efficiency and renewable energy. […]


Building and Buying

Part 7 of Elements of an Energy-Efficient House. Before you start a home-building project, the building site and its climate should be carefully evaluated to determine the optimum design and orientation for the house. There are energy-related computer software programs that can help with these evaluations. The design should accommodate appropriate insulation levels, moisture dynamics, […]


Advantages and Disadvantages

Part 6 of Elements of an Energy-Efficient House. Houses that incorporate all of the elements of energy efficiency mentioned in this series of articles have many advantages. They feel more comfortable because the additional insulation keeps the interior wall at a more comfortable and stable temperature. The indoor humidity is also better controlled, and drafts […]


Heating and Cooling Systems

Part 4 of Elements of an Energy-Efficient House. Specifying the correct sizes for heating and cooling systems in airtight, energy-efficient homes can be tricky. Rule-of-thumb sizing is often inaccurate, resulting in wasteful operation. Conscientious builders and heating, ventilation, and air-conditioning contractors size heating and cooling equipment based on careful consideration of the thermal envelope characteristics. […]


Thermal Envelope

Part 2 of Elements of an Energy-Efficient House. A thermal envelope is everything about the house that serves to shield the living space from the outdoors. It includes the wall and roof assemblies, insulation, air/vapor retarders, windows, and weatherstripping and caulking. Wall and Roof Assemblies Most builders use traditional wood frame construction. Wood framing is […]


Additional Options for Reducing Heat Loss and Gain through Windows

Part 4 of Energy-Efficient Windows. Movable insulation, such as insulating shades, shutters, and drapes, can be applied on the inside of windows to reduce heat loss in the winter and heat gain in the summer. Shading devices, such as awnings, exterior shutters, or screens, can be used to reduce unwanted heat gain in the summer. […]


Reducing Heat Loss and Condensation

Part 3 of Energy-Efficient Windows. Manufacturers usually represent the energy efficiency of windows in terms of their U-values (conductance of heat) or their R-values (resistance to heat flow). If a window’s R-value is high, it will lose less heat than one with a lower R-value. Conversely, if a window’s U-value is low, it will lose less […]


Heating the Pool Efficiently

Part 3 of Conserve Energy and Heat Your Swimming Pool with Solar Energy. If you are selecting a pool heater, ask for as energy-efficient model as you can afford. Several heat pump manufacturers make retrofit desuperheater coils for pool heating, and several make heat pumps for pool heating. These may be cost effective relative to […]


Reducing Water and Heat Loss

Part 2 of Conserve Energy and Heat Your Swimming Pool with Solar Energy. Almost all of a pool’s heat loss—about 95 percent—occurs at the surface, mostly through evaporation to the air and radiation to the sky. A pool cover is an effective means to keep heat (and water) in a pool by reducing evaporation of […]


Alternative Construction Materials: Earth-Sheltered Houses

Part 6 of Earth Sheltered Houses. A form of earth-sheltered house that has been receiving much attention is referred to as an “Earthship.” These houses are built to be self-contained and independent; their design allows occupants to grow food inside and to maintain their own water and solar electrical systems. Some builders believe they have […]


Construction Materials: Earth-Sheltered Houses

Part 5 of Earth Sheltered Houses. The construction materials for each type of structure will vary, depending on characteristics of the site, climate, soils, and design. However, general guidelines show that houses more deeply buried require stronger, more durable construction materials. Materials must provide a good surface for waterproofing and insulation to withstand the pressure […]


Beginning Your Project: Earth-Sheltered Houses

Part 2 of Earth Sheltered Houses. You may want to start your project by contacting the organizations that can help you locate architects, builders, and contractors with earth-sheltered building experience (a few are listed in the Source List). The experienced builders in your location can also ensure that construction plans meet area building code requirements, […]


How big should my solar thermal system be, and which features should I look for?

Part 4 of Heat Your Water With The Sun. Some of the answers to questions about system size and features depend on how you plan to use the solar system. Here, you’ll find general information on sizing systems for water heating, swimming pools, and space heating. To locate more specific information, please see Getting help. […]


Cooling Your Home Naturally with Fans and Ventilation

Part 1 of Cooling Your Home Naturally with Fans and Ventilation. You can save energy and money when you ventilate your home instead of using your air conditioner, except on the hottest days. Moving air can remove heat from your home. Moving air also creates a wind chill effect that cools your body. Ventilation cooling […]


Weatherization Projects

Part 4 of A Guide to Making Energy-Smart Purchases. Weatherization projects insulate and tighten the shell of the home. Such projects include, but are not restricted to, caulking and weatherstripping, improving or replacing windows, and installing insulation. Caulking and Weatherstripping Caulking and weatherstripping are the easiest and least expensive weatherization measures and can save more […]


Determine Energy-Savings Priorities

Part 3 of A Guide to Making Energy-Smart Purchases. Results from the energy audit can direct you to the changes that would be most appropriate to improve the energy efficiency, or “tightness,” of your home. Before you purchase an energy-related product or system, though, you should answer some important questions. What are your budgetary limits? […]


Blocking the Heat

Part 3 of Cool Your Home Naturally. Two excellent methods to block heat are insulation and shading. Insulation helps keep your home comfortable and saves money on mechanical cooling systems such as air conditioners and electric fans. Shading devices block the sun’s rays and absorb or reflect the solar heat. Insulation Weatherization measures—such as insulating, […]