Chapter 2- BPI Notecards - Heat and Insulation

U-Value

This measures how fast heat moves through a material.

dense-packing Ch. 2 p. 55

The practice of installing cellulose insulation at high density

convection loop Ch. 3 p. 41

The tendency of air to circulate around a space as the air is heated and cooled (warm, less dense air rises, while cooler, denser air falls)

radiation Ch.2 p. 41

The transfer of heat from a warm object through space to a cooler object (the objects must be in sight of one another) ex: fire place radiates heat to warm up a space. Window radiates coldness if it's cold outside. My body radiates warmth if cold inside.

convection Ch.2 p. 40

The transfer of heat through a fluid medium (usually air) ex: hvac system

Conduction Ch.2 p. 39 ex: paper cup with coffee transfers to your hands quicker. Foam cup is slower transfer aka better insulation cup. A home is the same way.

The transfer of heat through materials or objects in contact is called:

Diffusion Ch.4 p. 135

The transfer of water vapor through building materials such as sheetrock and plywood

Potential Energy Ch. 2 p. 35

An object at rest is said to possess what type of energy?

building envelope Ch.2 p. 50 aka building shell

Any part of the building assembly that creates a boundary between indoor and outdoors space

Heat moves in three ways:

Conduction (through materials in contact, convection (through a fluid medium, such as air), and radiation (through space, between objects that are within a line of sight). All three types of heat movement (or transfer) are at work in a house.

Home performance contractors are very much concerned with the performance of insulation in a house; this performance is typically expressed as an....

R-value

Chapter 2 Summary

Is about heat. We learn how it moves in a house and how it is measured, and controlled

batts Ch. 2 p. 56

Loose fiberglass can be held together with adhesive to create:

Permeability ch. 4 p. 143 aka short for perm

The ability of a material to allow water vapor to pass through it

Thermal Boundary Ch. 2 p. 51

The border between conditioned and unconditioned space in a house is called the: (where insulation is installed). ex: You want your conductive heat or cooling air to be comfortable in the living areas of your home. So insulate your conditioned space the right way or else convection (air moves through insulation materials) to unconditioned spaces.

bays ch. 1 p. 26

The cavity between studs in a framed wall.

Delta T p. 37

The difference in temperatures between two areas. ex: Heat wants to move to colder areas. If its 68 degrees in the living space and 24 degrees outside it will take more energy to heat that space because the heat wants to escape to the cold. Make sure it's insulated correctly so the heat won't escape!

Kinetic Energy Ch.2 p. 35

The energy of an object while it's in motion

Temperature Gradient Ch. 3 p. 91

The gradual change in temperature between two environment

Insulation is used to control what kind of heat?

conductive heat. fiberglass batts are the most common ways to insulate a house

2nd law of thermodynamics

heat moves from warmer areas to cooler areas (so heat may not always rise)