Unit 22 quiz #1 flashcards |

This is a Free Service provided by Why Fund Inc. (a 501 C3 NonProfit) We thank you for your donation!


(1. Click on the course Study Set you wish to learn.) (2. If you wish you can click on "Print" and print the test page.) (3. When you want to take a test...click on anyone of the tests for that Study Set.) (4. Click on "Check Answers" and it will score your test and correct your answers.) (5. You can take all the tests as many times as you choose until you get an "A"!) (6. Automated college courses created from lecture notes, class exams, text books, reading materials from many colleges and universities.)

New

Long-Term Learning

Learn efficiently and remember over time.

Start Long-Term Learning

Get personalized study reminders at intervals optimized for better retention.
Track your progress on this set by creating a folder
Or add to an existing folder

Add this set to a folder

  • 1.Why do some condenser have to be
    cleaned with brushes and others with chemicals

    Answer: So the condenser can properly reject heat without going into a high system pressure,
    The types that have to be clean with chemicals are types that are not excusable

    2.What are 3 materials condensers are
    normally made of ?

    Answer: Stainless steel, copper and nickel

    3.Who should be consulted when
    condenser cleaning is needed ?

    Answer : The manufacturer

    When is the most heat removed from the refrigerant in the condensing process.

    The greatest amount of heat that is given up from the refrigerant is while the condensing
    process is taking place, de superheating

    5.After heat is absorbed into a
    condenser medium in a water cooled condenser,the heat can be deposited in one of two places.What are they?

    Answer : The water can be used once, then wasted down the drain or where large amounts
    of water are being used, it is more economical to save water, cool it in an outside water tower and reuse it.

    6.A water cooling tower capacity is
    governed by what aspect of the ambient air?

    Answer : The wet bulb temperature of the air

    7.When a standard efficiency air cooled
    condenser is used the condensing refrigerant will normally be....F higher in temperature than the entering air temp .

    Answer : 30F higher than the outside air temp

    8.Four methods of controlling head
    pressure in an air cooled condenser are?

    Answer : Fan cycling controls, variable speed fans, shutters and condenser flooding controls

    9.The prevailing winds can affect which
    of the air cooled condensers?

    Answer : The cooling tower

    10.Air-cooled condensers are much
    more efficient than water-cooled condensers.

    Answer : (False) Water cooled condensers are much more efficient than air cooled condensers

    11.The type of condenser that has the
    lowest operating head pressure is the------ cooled condenser.

    Answer : The water cooled condenser

    12.Compare the standard conditions of
    high efficiency and standard air cooled condensers.

    Answer : High efficiency would be to have the condenser head pressure as close to the
    ambient air as possible.

    13.Name 2 ways in which the heat from
    an air cooled condenser can be used for heat reclaim?

    Answer : The discharge gas can be passed to the rooftop condenser or to a coil mounted in
    the duct work that supplies heat to the store.

    14.Briefly describe what is meant by
    floating head pressure and tell why it is used in refrigeration and AC system

    Answer : An industry term for attaining the lowest possible condensing pressure is called
    Floating head pressure. Floating head pressure systems simply let the condensing pressure follow the ambient temperature as the seasons swing from summer to winter.

    15.Explain how to flush impurities from
    a water regulating valve that is on a water cooled condenser.

    Answer : Water cooled condensers can be cleaned by brush or chemically

    16.Explain the basic operations of a
    combination ORI and ORD low ambient head pressure control valve.

    Answer : ORD valve sense a factory preset pressure difference of 20 psi between the
    receiver and compressor discharge , It will start to open and bypass hot compressor discharge gas to the receivers inlet The ORI valve stows refrigerant in the condenser to maintain the correct head pressure. Both the ORI and the ORD will work in conjunction of one another to maintain proper receiver pressure, regardless of outside temperature.

    17.Name two problems a refrigeration
    system may have if the condensing unit is exposed to low ambient condition when it is not using a low ambient head pressure control valve

    Answer : When the condensing medium is cold enough to reduce the head pressure to
    the point that the expansion device will starve the evaporator. And less head pressure cause less heat to be available for the heat reclaim coils to heat buildings

    18. Name 3 types of cooling towers?

    Answer : Natural Draft, Forced Draft, and Evaporative

    19.How much higher does a water
    cooled condenser condense at when using a cooling tower?

    Answer : 10F

    20.What must be added to the system
    to help water when it is evaporating from over concentrating minerals ?

    Answer : Water must be added to the system to keep this from happening

    21.Name the 3 types of water cooled
    condensers.

    Answer : Tube within a tube, Shell & coil, Shell & tube

    22.What is the component that rejects
    heat from the refrigeration system ?

    Answer : The Condenser

    Recirculating water uses what ? to help
    the cooling process.

    Answer : Evaporation

    Please allow access to your computer’s microphone to use Voice Recording.

    Having trouble? Click here for help.

    We can’t access your microphone!

    Click the icon above to update your browser permissions above and try again

    Example:

    Reload the page to try again!

    Reload

    Press Cmd-0 to reset your zoom

    Press Ctrl-0 to reset your zoom

    It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

    Please upgrade Flash or install Chrome
    to use Voice Recording.

    For more help, see our troubleshooting page.

    Your microphone is muted

    For help fixing this issue, see this FAQ.

    Star this term

    You can study starred terms together

    ! Voice Recording

    This is a Plus feature

    Create Study Set