AIR CONDITIONING & HEAT PUMP SYSTEMS
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COMBUSTION GASES & PARTICLE HAZARDS
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DEFINITION of Heating & Cooling Terms
HEAT LOSS in BUILDINGS
How to measure heat movement through a wall
How to measure building insulation
How leaky is the building
Priorities for building energy efficiency
Radiant Heat Floor Mistakes to Avoid
ENERGY AUDIT - How to Use a Free One
HEAT LOSS INDICATORS
HEAT LOSS R U & K VALUE CALCULATION
HEAT TAPES, Heat, Insulation prevent Freeze-Up
HEATING SYSTEMS
HEATING COST FUEL & BTU Cost Table
HEATING COST SAVINGS METHODS
HEATING LOSS DIAGNOSIS-BOILERS
HEATING LOSS DIAGNOSIS-FURNACES
HOUSEWRAP AIR & VAPOR BARRIERS
HUMIDITY LEVEL TARGET
INSULATION & VENTILATION INSPECTION & IMPROVEMENT
Insulation Material Identification Guide
LIST of Asbestos Containing Products
Mold Growth Resistance of Foam Insulation
Table of Properties of Insulating Materials
HUMIDITY LEVEL TARGET
HOUSEWRAP AIR & VAPOR BARRIERS
ICE DAM PREVENTION
MOISTURE, MOLD, ICE DAM LEAKS in ATTICS & ROOFS
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How to Measure & Correct unwanted Building Heat Losses
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This article explains how to insulate a building and how much insulation is needed including how to measure or calculate heat loss in a building, defines thermal terms like BTU and calorie, provides measures of heat transmission in materials, gives desired building insulation design data, and shows how to calculate the heat loss in a building with R values or U values. Because no amount of insulation can keep a drafty building warm, also review Priorities for building energy efficiency. Also see HEAT LOSS INDICATORS (where is the building losing heat during the heating season, or gaining un-wanted heat during the cooling season), and see HEAT LOSS R U & K VALUE CALCULATION for a guide to calculating heat loss (or gain) rates for buildings and building insulation.
Formula-R™ and Owens Corning™ which may be visible in this photograph of pink Styrofoam™ insulation boards are registered trademarks of Owens Corning® and were photographed at a Home Depot® building supply center. © Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
When we are evaluating the quality and effectiveness of insulation in a building or the adequacy of a building heating or cooling system, we need to use measurements that permit us to describe the rate at which a building loses heat under various conditions (such as outdoor temperature, wind velocity, how leaky the building is, the area of its windows and perhaps doors, and the amount of insulation in the building walls, floors, and ceilings. A few of these critical definitions is given just below, followed by some simple formulas used to calculate the heat loss in a building.
Definitions of BTUs, BTUH, and Calories
Definition of BTUs and BTUH: a BTU is one "British Thermal Unit" which is defined as the quantity of heat that would be required to increase the temperature of one pound of water by one degree Fahrenheit.
A BTUH is defined as the number of BTU's lost (if we're talking about heat loss or air conditioning), or provided (if we're talking about providing heat for a building) in one hour. You'll often see BTUH as a number on data plates on air conditioners and on heating systems.
One BTU is also equal to 252 calories. So what's a calorie?
Definition of Calorie or Calories: a calorie is defined as the quantity of heat needed to raise the temperature of one gram of water by one degree Centigrade.
How do we measure heat transmission or movement through a building wall, insulation, or any other material?
How do we measure and express how well a building is insulated? or How much heat loss is occurring at a specific building?
Many people have heard of using "R" values to describe "how good" a building's insulation is. Here we discuss three measures of the flow of heat out of or into a building: R-values, K-values, and U-values. Each of these is defined below. But before moving on to these basic concepts of building heat loss (or gain) theory, it is essential that this still more basic point be considered:
How leaky is the building with respect to heat loss (in a heating climate) (or gain in a cooling climate)?
It doesn't matter much how wonderful the building insulation is, how thick it is, or what the insulating material's "R" value is (see R defined below) if the building is leaky. If, for example, we're considering an older home with leaky windows or doors, or if we're considering a tall building with poorly controlled heat in winter, such that occupants of the upper floors are leaving windows open in winter then the heat flow out of these openings will be so terrific that the amount of insulation won't matter much.
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Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
AIR CONDITIONING & HEAT PUMP SYSTEMS
BLOWER DOORS & AIR INFILTRATION
INTERIORS
COMBUSTION GASES & PARTICLE HAZARDS
COMBUSTION PRODUCTS & IAQ
DEFINITION of Heating & Cooling Terms
HEAT LOSS in BUILDINGS
How to measure heat movement through a wall
How to measure building insulation
How leaky is the building
Priorities for building energy efficiency
Radiant Heat Floor Mistakes to Avoid
ENERGY AUDIT - How to Use a Free One
HEAT LOSS INDICATORS
HEAT LOSS R U & K VALUE CALCULATION
HOUSEWRAP AIR & VAPOR BARRIERS
HEAT TAPES, Heat, Insulation prevent Freeze-Up
HEATING SYSTEMS
HEATING COST FUEL & BTU Cost Table
HEATING COST SAVINGS METHODS
HEATING LOSS DIAGNOSIS-BOILERS
HEATING LOSS DIAGNOSIS-FURNACES
HOUSEWRAP AIR & VAPOR BARRIERS
INSULATION & VENTILATION INSPECTION & IMPROVEMENT
Insulation Material Identification Guide
LIST of Asbestos Containing Products
Mold Growth Resistance of Foam Insulation
Table of Properties of Insulating Materials
HUMIDITY LEVEL TARGET
HOUSEWRAP AIR & VAPOR BARRIERS
ICE DAM PREVENTION
MOISTURE, MOLD, ICE DAM LEAKS in ATTICS & ROOFS
- Asbestos pipe insulation in buildings
- Brick "Insulation" in Building Walls
- HEAT LOSS CALCULATIONS, Insulation Properties, Definitions of R, K, U values, Insulation Design
- How to Choose an Air Conditioner - BTU Chart
- How to Detect and Correct Attic Condensation & Prevent Ice Dam Leaks in Buildings
- How to Inspect Building Interiors and Building Insulation/Ventilation list of articles about building insulation inspection, defects, design, and ventilation requirements
- Insulation Materials as Indicators of Building Age
- Indoor Air Quality Investigations: Fiberglass in Indoor Air, HVAC ducts, and Building Insulation
- Insulation Identification Photographs - Cellulose insulation photos, Mineral wool insulation photos, rock wool insulation photos, cotton insulation photos, balsam wool insulation photos
- Insulation Identification Photographs - Vermiculite insulation photos
- LP or Natural Gas Pressures & BTUH per Cubic Foot
- Insulation Properties, Table of R-Values, density, moisture permeability, fire safety, aging effects on various insulation materials
- Mold in Fiberglass in Insulation
- Radiant Heat Floor Mistakes to Avoid
- Rated Cooling Capacity - How to Determine Air Conditioning Equipment Rated Cooling Capacity
- Un-Vented Roof Solutions - How to Prevent Attic Condensation, Ice Dam Leaks, Roof Mold, & Roof Structural Damage in Buildings with Un-vented Roof Cavities
- Vermiculite Building Insulation & Asbestos
BLOWER DOORS & AIR INFILTRATION
INTERIORS
HEAT LOSS in BUILDINGS
HEATING SYSTEMS
INSULATION & VENTILATION INSPECTION & IMPROVEMENT
MOISTURE, MOLD, ICE DAM LEAKS in ATTICS & ROOFS
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More Information on Building Diagnostic Inspections and Repairs
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