Results 1 to 32 of 32
  1. #1
    Join Date
    Apr 2006
    Location
    stafford
    Age
    36
    Posts
    986
    Rep Power
    13

    THE RE RULES OF THUMB,HINTS,TIPS and TRICKS



    Ok go with me on this one, RE has a massive following and many many members that all bring there own input to the form, so could we not create our own eBook contributed by the members for the members?

    Taking the best rules of thumb, hints, tips and tricks and collating them all?

    Every member that contributes gets the book and fill it with all the info we have scribbled on bits of paper in the van e.g sizing rules of thumb, condensate water produced per KW of cooling, air changing rules of thumb ect ect

    i am no computer whizz but would be willing to put my time to the project

    Good idea bad idea?

    OVER TO YOU GUYS
    Last edited by superswill; 28-04-2008 at 07:01 PM.


    Paul


    "KEEP IT COOL"

  2. #2
    Join Date
    Mar 2008
    Location
    stoke on trent
    Age
    54
    Posts
    8
    Rep Power
    0

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    excellent idea

  3. #3
    Join Date
    May 2007
    Location
    Northants
    Posts
    252
    Rep Power
    11

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Yeah sounds good

  4. #4
    Join Date
    May 2006
    Location
    aberdeen
    Posts
    125
    Rep Power
    12

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Sounds good, Count me in,,

  5. #5
    Join Date
    Jan 2008
    Location
    Kent UK
    Age
    42
    Posts
    520
    Rep Power
    11

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    wonderful idea but i expect there would be a lot of different opinions on certain practices,but i bet it would be good.
    If it ain't broke, it doesn't have enough features yet.


    Damo

  6. #6
    Join Date
    Jan 2001
    Location
    Fife, Scotland.
    Age
    59
    Posts
    1,194
    Blog Entries
    2
    Rep Power
    20

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    might be doable when the site gets upgraded
    <img src=http://www.refrigeration-engineer.com/forums/image.php?type=sigpic&userid=1&dateline=1296159097 border=0 alt= />

  7. #7
    Join Date
    Apr 2006
    Location
    stafford
    Age
    36
    Posts
    986
    Rep Power
    13

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by WebRam View Post
    might be doable when the site gets upgraded
    the boss has spoken so its up to us
    Paul


    "KEEP IT COOL"

  8. #8
    Join Date
    May 2007
    Location
    India
    Posts
    689
    Rep Power
    11

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    I am in too. We had a similar book mostly on AC etc. We need to have a similar compilation on Refrigeration.

  9. #9
    Join Date
    Sep 2007
    Location
    Split Croatia
    Age
    51
    Posts
    6,075
    Blog Entries
    6
    Rep Power
    30

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    I think that before anything, we need to establish origin of "Rule of thumb" term.

    Before thermometers were invented, brewers would dip a thumb or finger into the mix to find the right temperature for adding yeast. Too cold, and the yeast wouldn't grow. Too hot, and the yeast would die. This thumb in the beer is where "rule of thumb" comes from.



    A am for this in part of hints, tips and tricks but when it is rule of thumb in question, I prefer measuring and calculations.
    Last edited by nike123; 29-04-2008 at 06:56 AM.
    Now, when I am officialy citizen off EU, I am looking for decent job! For any job offer please check my profile!

  10. #10
    Join Date
    Apr 2006
    Location
    stafford
    Age
    36
    Posts
    986
    Rep Power
    13

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by nike123 View Post
    I think that before anything, we need to establish origin of "Rule of thumb" term.

    Before thermometers were invented, brewers would dip a thumb or finger into the mix to find the right temperature for adding yeast. Too cold, and the yeast wouldn't grow. Too hot, and the yeast would die. This thumb in the beer is where "rule of thumb" comes from.



    A am for this in part of hints, tips and tricks but when it is rule of thumb in question, I prefer measuring and calculations.

    rule of thumb:

    noun
    1. a general or approximate principle, procedure, or rule based on experience or practice, as opposed to a specific, scientific calculation or estimate.

    2. a rough, practical method of procedure

    To clarify:

    I am after/asking the members of RE if creating a EBook of handy, hints, tips and good working practises would be of interests
    Paul


    "KEEP IT COOL"

  11. #11
    Join Date
    Dec 2006
    Location
    Mansfield
    Age
    50
    Posts
    232
    Rep Power
    0

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Well put over superswill.


    PP

  12. #12
    Join Date
    May 2008
    Location
    ireland
    Age
    35
    Posts
    45
    Rep Power
    0

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by WebRam View Post
    might be doable when the site gets upgraded
    Just found this thread. sounds like a good idea.

    Anybody want to start the ball rolling?

  13. #13
    Join Date
    Apr 2006
    Location
    stafford
    Age
    36
    Posts
    986
    Rep Power
    13

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    iam up for it
    Paul


    "KEEP IT COOL"

  14. #14
    Join Date
    Sep 2007
    Location
    Somerset
    Age
    63
    Posts
    4,468
    Rep Power
    38

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Rock Hard and baked on Gaskets.

    Prior to removal, say just as you remove the covers, take a rag and dip it in some of the oil that's ALLWAYS around and wipe the gaskets with the oily rag.

    WHEN YOU COME TO REMOVE THE GASKETS.
    THEY WILL PRACTICALLY FALL OFF!
    TRY IT!!
    Grizzly

  15. #15
    Join Date
    May 2008
    Location
    ireland
    Age
    35
    Posts
    45
    Rep Power
    0

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by Grizzly View Post
    Rock Hard and baked on Gaskets.

    Prior to removal, say just as you remove the covers, take a rag and dip it in some of the oil that's ALLWAYS around and wipe the gaskets with the oily rag.

    WHEN YOU COME TO REMOVE THE GASKETS.
    THEY WILL PRACTICALLY FALL OFF!
    TRY IT!!
    Grizzly
    After loosening bolts, I find that tapping both sides of fllange or fitting, fairly heavy with a hammer also works well

  16. #16
    Join Date
    Sep 2007
    Location
    Somerset
    Age
    63
    Posts
    4,468
    Rep Power
    38

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by cmac View Post
    After loosening bolts, I find that tapping both sides of fllange or fitting, fairly heavy with a hammer also works well

    Hi cmac.
    Sorry I mislead you a bit there.
    I mean once the covers are off and you are left with those stubborn bits that don't want to come off!
    Cheers Grizzly

  17. #17
    sabyashachibasu's Avatar
    sabyashachibasu Guest

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Thats cool.Pleas count me as i am a new

  18. #18
    Join Date
    Oct 2006
    Location
    England
    Posts
    1,848
    Rep Power
    15

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by cmac View Post
    Anybody want to start the ball rolling?

    When working in freezers if the hairs in your nose freeze up it IS cold enough.

    Touching your wet finger to the frozen pipe may let you know if it is below freezeing but don't lick the pipe.

    RULE OF TEN.
    The ten degree rule.
    The liquid in the evap boils 10 degrees lower than the air off and the air off is 10 degrees lower than the air on. The air off a cond is 10 degrees higher than the air on and the vapour condenses in the cond 10 degrees higher than the air off.

    Airflow can be tested by the back of the hand but direction on low velocity air can be hard to prove so hold a thin piece of paper in the air and see which way it moves.

    When takeing a compressor to pieces as you remove a cover or a cylinder head put all the bolts and fittings for that individual piece inside the cylinder head or cover.Then you can keep them all together and you will know which bits go where when rebuilding.

    When rebuilding the compressor always throw a spare bolt in the sump. It gives the next engineer somthing to think about ONLY JOKEING....


    Cheers taz.
    Last edited by taz24; 30-05-2008 at 01:21 PM.

  19. #19
    Join Date
    May 2008
    Location
    Northern NSW, Australia
    Age
    50
    Posts
    33
    Rep Power
    0

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    When entering an office full of hot/cold ladies,

    firstly goto the closest plant room and tap your spanner around for a minute.

    Then walk around with your thermometer asking if they feel better.

    Must be the warm fuzzy feeling of a nice fridgy that they needed.
    Doesn't work all the time...

  20. #20
    Join Date
    Oct 2006
    Location
    England
    Posts
    1,848
    Rep Power
    15

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by Jadeair View Post
    When entering an office full of hot/cold ladies,

    firstly goto the closest plant room and tap your spanner around for a minute.

    Then walk around with your thermometer asking if they feel better.

    Must be the warm fuzzy feeling of a nice fridgy that they needed.
    Doesn't work all the time...

    So so true.
    I agree and the other one is always make sure the plant room / engine room looks clean and tidy.
    You may be the worst engineer in the world but if the customer sees you cleaning all the oil and polishing all the brass he will love you forever

    taz.

  21. #21
    Join Date
    Sep 2007
    Location
    Somerset
    Age
    63
    Posts
    4,468
    Rep Power
    38

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by taz24 View Post

    When rebuilding the compressor always throw a spare bolt in the sump. It gives the next engineer somthing to think about ONLY JOKEING....


    Cheers taz.
    I actually had a colleague who rebuilt a large Halls recip and whilst clearing up..
    Complained that his torch (flash light) was missing.
    Then noticed that there was a glow from within the compressor sump, (seen through the sight glass).

    Yes! He had replaced the sump cover but forgot to remove the torch he had been using to inspect the big ends with!!!!!

    We still laugh about tha one nowadays.
    Grizzly

  22. #22
    Join Date
    Oct 2006
    Location
    England
    Posts
    1,848
    Rep Power
    15

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by Grizzly View Post
    I actually had a colleague who rebuilt a large Halls recip and whilst clearing up..
    Complained that his torch (flash light) was missing.
    Then noticed that there was a glow from within the compressor sump, (seen through the sight glass).

    Yes! He had replaced the sump cover but forgot to remove the torch he had been using to inspect the big ends with!!!!!

    We still laugh about tha one nowadays.
    Grizzly


    Its funny the things we do and that the manager or customer should never know about

    Did he wait till the batteries ran flat and then said goodbye to his trusty old torch as the light flickered one last time or did he do the right thing and jump right in to save his old companion

    Cheers taz.

  23. #23
    Join Date
    Sep 2007
    Location
    Somerset
    Age
    63
    Posts
    4,468
    Rep Power
    38

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by taz24 View Post
    Its funny the things we do and that the manager or customer should never know about

    Did he wait till the batteries ran flat and then said goodbye to his trusty old torch as the light flickered one last time or did he do the right thing and jump right in to save his old companion

    Cheers taz.
    Yes!
    He saw the light!
    And retrieved it. (After all it was an "Ever Ready".)
    Grizzly.

  24. #24
    Join Date
    Jun 2005
    Location
    Lancs
    Age
    54
    Posts
    21
    Rep Power
    0

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Myself and a collegue once rigged up a bog standard room thermostat in a large high street store and ran a flex up to the ceiling and poked it through the plaster and told the ladies in the vicinity that they now had total control of the temperatures around them using said stat ....... they were over the moon ........ naturally the stat was not connected

  25. #25
    Join Date
    Jun 2005
    Location
    Lancs
    Age
    54
    Posts
    21
    Rep Power
    0

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    However as a rule of thumb I would be interested to know how long one should conduct a pressure / leakage check for, on a system that has been found to have a leak(s) should a leak be found and repaired. I have checked our governing bodies websites and the only clue I have is ..... " a suitable length of time should pass at the relevant pressure for the refrigerant in use " . My point is what does one class as a suitable length of time ?

  26. #26
    Join Date
    Mar 2010
    Location
    India
    Posts
    101
    Rep Power
    8

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by WebRam View Post
    might be doable when the site gets upgraded
    I think this thread should be sticky or display at the front page of RE so that everyone can see this thread & give reply from their great experiences

    I am trying to collect information at one place if it is wrong please correct it

    Kindly share the knowledge for our RE

    AIR CONDITIONING

    Thumb rules will always get you in trouble. Always reminding that thumb rule is for checking only

    Ac size
    Thumb rule vary according to country environment

    Volume of room in cubic feet multiplied by five gives the cooling capacity required in BTU'S

    Floor area x 125w/m2 to give you a high end kw rating.

    Room 13m x 10mx 3m
    13m x 10m = 130m2
    130m2 x 125w/m2 = 16.25kw

    Gymnasiums = 300w/m2
    Server Rooms = 400w/m2


    Cooling load estimation
    150 W/m2 for ordinary room
    190 W/m2 for computer room

    12,000 BTU,s = 1Ton Refrigeration & 1TR = roughly 3.5 KW

    Compressor:
    The compressor should start no more than 6 times per hour

    Indoor & Outdoor
    Indoor fed 9, 12 and 18000 Btu. & outdoor fed 24K always

    Pressure:
    For R22 condensing pressure should be 19K to 22K above ambient temp equivalent pressure (air-cooled)


    Cooling output:
    (air on C - air off C) x air vol m/sec x 1.2 (density of air) = kW

    Air flow:
    The amount of air flowing depends on the sensible cooling load of the space.
    400 cfm per ton is a good


    The exact outside air temperature below which the unit needs regular defrost at 7 deg C is an approximate


    RULE OF THUMB

    http://www.daikinaltherma.com:8080//SpaceAirSite/index_SA.jsp?mt=991&taxonomy_id=991&lang=en&site=991

    http://www.daikinaltherma.com:8080//SpaceAirSite/index_SA.jsp?mt=992&taxonomy_id=992&lang=en&site=992

    http://www.daikinaltherma.com:8080//SpaceAirSite/index_SA.jsp?mt=993&taxonomy_id=993&lang=en&site=993

    http://www.daikinaltherma.com:8080//SpaceAirSite/index_SA.jsp?mt=994&taxonomy_id=994&lang=en&site=994

    http://www.daikinaltherma.com:8080//SpaceAirSite/index_SA.jsp?mt=995&taxonomy_id=995&lang=en&site=995

  27. #27
    Join Date
    Jul 2010
    Location
    NTH.QLD Australia
    Age
    55
    Posts
    1,754
    Rep Power
    26

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    How about 65 btu/sq ft for home a/c where ambient can exceed 32c and insulation installed in the roof.

  28. #28
    Join Date
    May 2009
    Location
    aust
    Age
    47
    Posts
    14
    Rep Power
    0

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    when i did my time in nz an old engineer welded abit of 3/8 cu tube to a bit of 1/2 cu tube and fitted flare nuts (welded)to the pipe the txv was buggered but he set the super heat with 2 *12 inch shifters till the morning. the copper acted as a metering devise and i was left to tension the nuts if the liquid came back.funny but true and worked .cheap labour back then

  29. #29
    Join Date
    May 2009
    Location
    aust
    Age
    47
    Posts
    14
    Rep Power
    0

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    50/100 watts m2

  30. #30
    Join Date
    Sep 2008
    Location
    england
    Posts
    430
    Rep Power
    14

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    A get out of trouble on a Saturday afternoon idea when there`s vibration loosening nuts. Cut a slot in the nut just into the thread then crush the nut to close the gap. this will act as a simmonds nut and prevent it from vibrating lose. Just be careful though as it will be weaker.
    Another one is when a tapped hole is cross threaded. Cut three slots in a slight spiral up a bolt (obviously the same thread) and carefully screw it in the hole. This acts as a tap and with luck it`ll clean the damaged thread up.
    As I said earlier these are get out of jail cards when youre in a fix.

  31. #31
    Join Date
    Sep 2008
    Location
    england
    Posts
    430
    Rep Power
    14

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Another one I remembered from my days on the railways working as an apprentice under the old steam boys. When opening a gate valve (or Rotolock valve), open it fully to its stop then turn it back half a turn. Anyone trying to open it later will Know it`s already open as it only turns half a turn. Many a time I`ve tried opening a valve suspecting it seized only to find someones wound it fully open.
    Also if it is seized that half a turn should be enough to free any crap behind it.

  32. #32
    amoureman's Avatar
    amoureman Guest

    Re: THE RE RULES OF THUMB,HINTS,TIPS and TRICKS

    Quote Originally Posted by superswill View Post
    Ok go with me on this one, RE has a massive following and many many members that all bring there own input to the form, so could we not create our own eBook contributed by the members for the members?

    Taking the best rules of thumb, hints, tips and tricks and collating them all?

    Every member that contributes gets the book and fill it with all the info we have scribbled on bits of paper in the van e.g sizing rules of thumb, condensate water produced per KW of cooling, air changing rules of thumb ect ect

    i am no computer whizz but would be willing to put my time to the project

    Good idea bad idea?

    OVER TO YOU GUYS
    great idea some sercice tips and quick tricks to resolveing puzzling problems would be good too

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •