Understanding Insulation

U.S. Department of Energy Recommended Total R-Values for New Wood-Framed Homes by Region UNDERSTANDING INSULATION Well Home. Improve the weather inside. Benefits of Insulation a. Insulation improves the comfort of the home. b. Insulation can reduce the cost of heating and cooling significantly. c. Adding insulation usually pays for itself in five to six years. d. Insulation reduces the energy used for heating and cooling, which reduces greenhouse gas emissions. e. Adding insulation virtually elimi- nates condensation on walls or ceilings. f. Insulation sometimes also doubles as sound-proofing, reducing noise between rooms or from outside the house. A. Radiation: Directed heat which can be felt by the skin, such as the sun's ray. Insulation Performance Insulation materials are rated for their performance in restricting the transfer of heat. This performance is expressed as the "R Value." The R value is essentially a guide to the quality and performance of the insulator. The higher the R value, the greater the insulating effect. R values are expressed using the metric units m2/K/W where: B. Conduction: C. Convection: The Uninsulated Home An uninsulated home is subject to considerable winter-heat losses and summer-heat gains and can suffer from deficiencies in stopping all three types of heat transfer. Understanding The Insulated Home Heat transferred through the movement of gasses or liquids. For instance, when air is warmed, it rises and is replaced by cooler air below. Types of Insulation Bulk Insulation: Bulk insulators block conductive heat transfer and convective flow either into or out of a building. The denser a material is, the better it will conduct heat. Because air has such low density, air is a very poor conductor and therefore makes a good insulator. Types of bulk insulation include: Batts and blankets a. Glasswool (fibreglass) Made from melted glass spun into a flexible mat of fine fibres. Reflective foil reflects significant amounts of radiant heat and emits only a small amount, keeping your home warmer in the winter and cooler in the summer. Heat transferred from warm to cool areas within a material or between two materials touching each other. Gases, such as air, are poor conductors of heat, while solids, particularly metals, are usually better conductors of heat. Insulation is the most effective way to improve the energy efficiency of a home. WALL Loose-fill insulation Loose fill insulation consists of shredded or granulated material in a loose form and is usually installed by the supplier or manufacturer. It must be installed correctly at an even depth to provide proper insulation. Loose fill materials settle over time, sometimes reducing its effectiveness. Make sure you understand your loose fills "settled R value" which is the R value of the material after it has fully settled over time. Reflective Insulation Reflective insulation works by reducing the radiant heat transferred across an enclosed space such as between bricks and plasterboard. Reflective foil in walls or under the roof can also reflect heat away from the interior in the summer. Types of reflective insulation include: Heat Transfer There are three ways in which heat can be transferred: Insulation helps keep heat in during the winter, but lets heat out during the summer to improve comfort and save on energy. Insulating a home can save 45-55% of heating and cooling energy. The table below shows a breakdown of these savings by the extent of insulation: Insulation Having adequate levels of insulation is essential to reducing energy loss and creatinga comfortable environment inside your home, Attic Cathedral Ceiling Cavity Floor Zone Sheathing Ceiling Ceiling 25-35% R13 to R15 R13 to R15 R13 to R15 R13 to R15 R13 to R15 R13 to R21 R13 to R21 R13 to R21 None R13 to R15 Emits 5% of all radiant heat 25-35% R30 to R49 R22 to R38 Reflects 95% of radiant heat Walls R30 to R60 R30 to R60 EXTENT OF INSULATION COOLING HEATING HEATING & COOLING When your home was built, the builder probably installed the recommended amount of insulation at the time, Given today's energy prices and new advancements in insulation technologies, your current level of insulation may no longer beadequate, b. Multi-cell reflective foil products R22 to R38 None R13 to R15 b. Rockwool Made from volcanic rock melted at high temperatures and spun into a mat of fine fibres. c. Natural wool Made from sheep's wool formed into batts or blankets. d. Polyester Made from polyester fibres (including recycled PET bottles) spun into a flexible mat. a. Reflective foil laminate Foil laminated to paper with glass fibre reinforcement. II m2 refers to one meter squared of the material of a specific thickness. 15-25% Two, three or four layers of laminat- ed foil separated by partitioning to provide a one, two or three-layered cell structure. 3 R13 to R15 R13 to R15 R13 to R15 R13 to R15 R13 to R15 R13 to R21 a. Cellulose fibre Made from waste paper pulverised into a fine fluff. b. Natural wool Natural sheep's wool off-cuts. c. Granulated rockwool A loose-fill form of rockwool. R22 to R38 None Summer & Winter Losses in Poorly Insulated Homes Ceiling only (added R2.5) 30-45% Savings 15-25% Savings 20-30% Windows 4 R38 to R60 R30to R38 R2.5 to R6 Walls Savings K refers to one degree temperature difference across the material. R2.5 to R6 R5 to R6 R38 to R60 R49 to R60 R49 to R60 R49 to R60 10-20% R30 to R38 Ceiling (added R2.5) and walls (added R1.0) 15-25% 40-55% 40-50% 40-50% Bulk insulation traps air in still layers R30 to R60 R30 to R60 Savings Savings Savings c. Expandable concertina- style foil Double-sided reflective foil formed into an expandable concertina. d. Foil bonded to bulk insulation Reflective foil bonded to batts, blankets or polystyrene boards. Windows Air leakage This infographic isa guide to understanding insulation so you can better gauge your needs, W refers to the amount of heat flow across the material in watts. R5 to R6 15-25% Ceiling (added R2.5), walls (added R1.0) and floor (added R1.0) 25-35% Tiny pockets of trapped air 35-50% 45-55% 45-55% Savings Savings R30 to R60 R5 to R6 Savings Air leakage Floor 5-15% 10-20% Heat flow 1. 2. 6.