Residential Energy Audit - Chapter 8

Window glass with low solar heat gain coefficient (SHGC) will reduce cooling load, but heating efficient is improved by windows with a low U-factor.

• True

• False

Window glass with low solar heat gain coefficient (SHGC) will reduce heating load.

• True

• False

Low humidity helps reduce cooling energy consumption, but not heating consumption.

• True

• False

A home's cooling energy consumption depends on:

• Shading

• Window-U factors.

• Making it as reflective as possible.

• The use of night time ventilation.

• Heat tolerance of the it's residents.

The combination of  - radiant temperature - humidity - air movementdetermine comfort level .

• True

• Flase

___________ & ____________ determine the rate that a human body can loose heat.

• Shading & windows

• Air temperature & radiant temperature

• Air conditioning systems and window size

The _____________ determines the rate that a human body can reject heat by evaporation of sweat.

• Air flow

• Relative convection

• Relative humidity

• Dew point

Absorbed summer sunlight raises wall & ceiling temperatures, making these surfaces radiant heaters.

• True

• False

Relative humidity is the percent at which air at any temperature is ___________ with water vapor.

____________ is the temperature at which condensation begins.

• Relative humidity

• Minimum temperature

• Dew point

Evaporative coolers are a excellent energy saving option for locations with high humidity & high dew point.

• True

• False

Ventilation works well when the relative humidity  is up to _____%.

• 100%

• 90%

• 80%

• 70%

• 10%

Air conditioners must remove moisture from the air to improve indoor comfort.

• True

• False

Circulating air inside your home will:

• Make you feel cooler

• Increases evaporation of sweat

• Carries heat away from your skin

• Have no significant effect on your comfort level

There are four types of heat gain in a home: - ______________ - internal heat gain - air leakage heat gain - temperature driven heat transmission

In most climates solar heat gain contributes about ___% of the total heat accumulation indoors.

• 30%

• 50%

• 90%

Solar energy falling on the roof coming trough the windows  account for most of a house's solar heat gain.

• True

• False

Internal heat gains refer to

• Heat gain from the sun's rays coming through a window

• Heat gain from the heated ceilings and walls

• Heat gains from lightning, refrigeration, water heating, other appliances and the body of heat from the people inside the house.

Efficient appliances produce less waste heat.

• True

• False

Air leakage contribute to about 20% of summer heat gain.

• True

• False

Of the four heat gain factors (solar gains, internal gains, air leakage, heat transmission), heat transmission trough the shell of the house is the most important.

• True

• False

Heat transmission typically represents around ____% of the total load.

• 10

• 20

• 50

Energy conservation measures that block the sun before it strikes the roof or windows are the most effective.

• True

• False

Trees and plants that provide shade is the best long term investment for reducing cooling costs

• True

• False

A well planned landscaping program can reduce an unshaded home's summer air conditioning costs by ___% to ___%.

• 5 to 10

• 10 to 50

• 50 to 100

Trees and shrubs create a micro climate, increasing the shaded area's temperature.

• True

• False

Shading & _____________ (the process by which a plant releases water vapor) from trees can reduce the air temperature by as much as 9 deg F compared to unshaded areas.

• Evapostatic

• Evapotranmisson

• Evapotranspiration

Southern exposure needs __________ trees to block the sun from the south during the summer.

• Shorter

• Taller

• No

East and west vegetation should block  ____________sun during the summer.

• Lower-angle

• Higher-angle

• Only the afternoon

Studies by Lawrence Berkley Laboratory estimates that planting trees is ten times more cost effective than building new power plants for summer cooling.

• True

• False

Which of the following factors that are true for when you consider shading windows?

• Direction of windows

• Location of natural shade

• All windows, even windows shaded by trees, should be covered by an awning.

• Shading devices for larger windows are more cost effective than smaller windows.

• Shading devices offer the same cost effective savings for large windows as it does for smaller windows.

Window sunscreen fabric absorbs ___% to ___% of solar heat before it enters the home.

• 15 to 20

• 65 to 70

• 95 to 100

Window sunscreen must be installed on the __________ of the window to be effective.

• Interior

• Exterior

Window sunscreen must be installed on the exterior of the window to be effective and therefor are not practical for outwardly opening windows such as awning or casement windows, unless attached to  movable sash.

• True

• False

Metalized window plastic film can block _____% to ____% of solar heat on single pane glass.

• 10 to 25

• 30 to 40

• 50 to 75

Tinted film is as effective as metalized film.

• True

• False

Older types of metalized film do have the disadvantage of blocking out daylight in addition to solar heat.

• True

• False

Select the option below that are in order of least expensive (best return on investment) to most expensive (lesser return on investment).

• Awnings; sun screen; Trees

• Trees, sun screens, awnings

• Sunscreen, trees, awnings

The most important considerations in choosing an awning design are:

• Canvas color

• Amount of shade desired.

• Importance of maintaining a view out the window.

• Cost of the awning.

Awnings on the south side need a drop measurement of ___% to ___% of  the window height to block solar radiation from high in the sky.

• 15 to 20

• 45 to 60

• 85 to 100

Awnings on the west & east side need a drop measurement of ___% to ___% of  the window height to block solar radiation from lower in the sky.

• 10 to 25

• 60 to 75

• 85 to 100

Exterior shutters and shades are commonly more expensive that other method used to block the sun entering the window.

• True

• False

Replacement windows are a cost effective measure for reducing cooling costs.

• True

• False

What does SHGC stand for?

• Solar heat gain calculation

• Solar heat gain coefficient

• Solar high gain cost

Solar heat gain coefficient is:

• The ratio between solar heat entering through the glass to the solar heat falling on the glass at an 90 deg angle.

• The sum of solar heat entering through the glass to the solar heat falling on the glass at an 90 deg angle.

• The amount of light that is admitted through the window.

Visible transmittance measures how much light passes through the window glass.

• True

• False

Shading coefficient is

• A percentage amount that compares window glass' transmittance with that of window awnings.

• A percentage amount that compares window glass' transmittance with that of clear glass.

• A decimal number that compares window glass' transmittance with that of clear glass.

A reflective glass window has a shading coefficient of 0.55. The window glass will transmit ___% of the solar energy compared to that of clear glass.

• 0.55

• 5.5

• 55

• Less than zero