Controls CORRECT 100%
Define Thermal Energy - ANSWER Energy associated with the movement of molecules and measured as
heat
Define Electrical Energy - ANSWER Energy associated with the flow of negatively charged electrons
through a conductive medium.
Define Mechanical Energy - ANSWER The sum of kinetic and potential energy. Kinetic being the energy of
motion, potential being stored energy.
Define BTU - ANSWER Quantity of heat possessed by an object is measured in BTU. It is the amount of
heat required to raise temp of one pound of pure water one degree F at sea level.
What is the fundamental law of heat transfer? - ANSWER heat always flows from an object that is
warmer to an object that is cooler.
What are the three factors affecting amount and rate of heat flow through a building envelope? -
ANSWER 1. Total surface area
2. Temperature differences
3. Material properties.
What are the four factors uses to evaluate the materials that form a building enevlope? - ANSWER 1.
Thermal Conductivity
2. Thermal Conductance
3. Thermal Resistance
4. Overall Coefficient of heat transfer
What is thermal conductivity? - ANSWER The measurement of a materials ability to conduct heat.
,What is thermal conductance? - ANSWER A measure of the rate of heat flow through a material or air
space.
What is thermal resistance? - ANSWER A materials ability to retard heat flow.
What is the overall coefficient of heat transfer? - ANSWER Resistance value of all building materials, air
spaces, including walls, ceilings and surface air films.
What happens when heat is added to a substance? - ANSWER It's molecular motion increases.
What is temperature? - ANSWER The measurement of the intensity of heat.
What does a BTU measure? - ANSWER The quantity of heat.
What is sensible heat? - ANSWER heat that when added to or removed from a substance it changes the
temperature of the substance
What is specific heat? - ANSWER The ratio of the temperature it takes to raise the temperature of a
substance 1 degree to the amount of heat it takes to raise a pound of pure water 1 degree.
What is the formula for determining the amount of heat required to change the temperature of a
substance without changing the substances state? - ANSWER Heat required in BTU - weight in LB X
specific heat X temp change in degrees F.
What is latent heat? - ANSWER Heat that when added or removed from a substance changes that
substances state, but not its temperature.
What are the standard terms used to describe the change of a substance from one state to another
through the absorption or release of latent heat? - ANSWER solid to liquid: melting
liquid to solid: fusion
liquid to gas: vaporization
, gas to liquid: condensation
What are the three basic processes of heat transfer? - ANSWER Conduction, Convection, Radiation
What is conduction? - ANSWER Heat transfer through matter, molecule to molecule, due to temp
difference
What is convection? - ANSWER Heat transfer through fluid, typically air or water
What is radiation? - ANSWER Heat transfer through electromagnetic waves
What is scale formation? - ANSWER mineral deposits on a metal surface that have precipitated out of a
solution
What happens to a boiler with excessive scaling? - ANSWER Reduced steam output, excessive fuel use,
increase in stack temp.
What should be done to the feedwater treatment if scale is present? - ANSWER modify schedule and/or
add chemicals.
What else can be done to reduce scale? - ANSWER Use blowdown controls.
What aspects of building design to climate conditions influence? - ANSWER Orientation, configuration,
envelope, energy requirements, illumination, heating, HVAC requirements.
What climatic conditions affect buildings energy use? - ANSWER Temperature variation, quality of
sunlight, wind velocity and direction, and snowfall
What are some solar controls that are used to reduce heat losses and gains caused by windows? -
ANSWER Curtains, awnings, tinted glass, reflective films.