EGEE 102 Lesson 8
COP =
(Useful heat pumped to a higher temp) / (work put in)
Radiant floor systems heat _____. A ) the entire floor B ) localized spots C ) Some corners of the room
A
Which one of the following is an example of thermal mass? A ) Stone B ) Straw C ) Styrofoam D ) Wood
A
Which one of the following items is used in a passive solar heating system? A ) South facing windows B ) Photo-voltaic Cells C ) Flat Plate Collectors D ) A Geothermal Heat Pump
A
A freezer maintains a temperature of 30ºF while the outside temperature is 75ºF. What is the COP of the freezer cooling system? A ) 1.67 B ) 11.8 C ) 15.6 D ) 11.5
B
A heat pump with a COP of 5 maintains an indoor temperature of 65ºF. What is the temperature outside? A ) 20ºF B ) minus 40ºF C ) minus 30ºF D ) 50ºF
B
If a heat pump is used to heat a house in the winter, how will the Coefficient of Performance be affected if the inside set temperature is changed from 70 F to 65 F? A ) it stays the same B ) it increases C ) it may become negative D ) it decreases
B
In a baseboard radiator, _________increase(s) the surface area, which in turn leads to more efficient heat transfer. A ) Ducts B ) Fins C ) Gas combustion D ) Oil Heating
B
What is the process by which forced-air furnace systems distribute heat? A ) Conduction B ) Convection C ) Radiation D ) None of the above
B
What type of air system is most commonly used in central heating and cooling systems? A ) Hydronic B ) Electric Resistance C ) Forced Air Duct D ) Radiant baseboard
C
T/F: Horizontal loop geothermal heat pumps are used when there is less space available.
False
Which one of the following devices can be used to both heat and cool a house?
Heat Pump
Are radiant air floors cost effective?
No because air cannot hold large amounts of hear
Does the heat in the ground remain constant throughout the year?
Yes
what is a heat mover
a device that moves the heat from a low temp environment to a high temp environment
What are forced air heating systems?
a furnace warms airs, an air conditioner cools air, or a heat pump either warms or cools air, then a blower forces the air through the system
Where the branches meet the main, how is heat controlled?
by dampers which open or close to release or block heat from entry
Most newer homes are heating used _____________.
central heating systems
Most common floor covering for radiant floor heating?
ceramic tile
active solar heating system
comprised of collectors, a distribution system, and a storage device
what is a gravity heating system?
convection currents carry heated air through the system from a furnace that is located on or below the main floor level no blowers can only deliver warm air
what is electric resistance heat
converts nearly 100% of energy in electricity to heat more expensive can be supplied by centralized forced-air furnaces or by zonal heaters in each room
GHPS do not ______ heat , they _______ it from one area to another
create, move
passive solar heating system
do not use mechanical devices but instead use natural heat flow to distribute warmth
How does an upward-flow furnace work?
draws cold air in through the bottom and sends heated air out the top
How does a downward-flow or counter-flow furnace work?
draws cool return air through the top and delivers air out the bottom
Most common type of central heating and cooling used
ducted air systems
what powers air-source and air-to-air heat pumps?
electricity
Solar and GHP heating systems have absolutely no impact on the environment. A ) TRUE B ) FALSE
false
What kinds of heating systems are used for home and commercial buildings?
furnaces, boilers, or electric resistance heat powered by conventional fuels
Most cost effect type of GHP installation?
horizontal
What type of wood flooring would be best for a kitchen?
laminated wood
What is a hydronic (liquid) system?
pump heated water from a boiler through tubing laid in a pattern underneath the floor
how do forced air heating systems work?
room air (cooler) is drawn by a fan or a blower through return air registers and ductwork, and passes through a filter into a furnace, where the air is heated and blown back to rooms through a system of supply ducts and registers
Least effective type of flooring for home heating system
solid wood
Difference between ground source and air source
source of heat is the ground instead of outdoor air
Where does the heat in the ground come from?
sun
higher the temperature of air . . .
the higher its energy content
What type of carpeting should be in use in his family room?
thin carpeting with dense insulation
When are heat pumps used?
to provide space heating
T/F: The furnace/air conditioner will run for longer periods of time when the air filter is dirty.
true
T/F: The home heating and cooling system is the major residential user of energy
true
We know that, electrical resistance heating systems approach an efficiency of 97%. Electrical baseboard heating is more efficient than a heat pump. A ) TRUE B ) FALSE
true
how is the efficiency of a heat pump measured?
using a Coefficient of Performance (COP)
In hot air system, warm air is distributed how?
via a main duct and a series of branches that lead to individual rooms or zones
What are baseboard radiators?
water is heated in a gas-fired or oil-fired furnace located in basement and is distributed through pipes into baseboards in various rooms heat is delivered through radiation and convection
Oldest form of modern radiant floor systems?
wet installations
what is the balance point of a heating system?
when the temperature of the home's heating requirement and the heat pump output match usually between 30-45 degrees
how heat pump works in winter vs summer
winter: heat pump extracts heat from outside air and delivers it indoors summer: heat pump extracts heat from room air and pumps it outdoors to cool the house
can heat pump both heat and cool the air?
yes but only air source or air-to-air heat pump
