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superswill
28-04-2008, 06:56 PM
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

leey
28-04-2008, 07:18 PM
excellent idea

chillyblue
28-04-2008, 08:55 PM
Yeah sounds good

stuartwking
28-04-2008, 09:11 PM
Sounds good, Count me in,,

Chunk
28-04-2008, 09:14 PM
wonderful idea but i expect there would be a lot of different opinions on certain practices,but i bet it would be good.:D

WebRam
28-04-2008, 10:14 PM
might be doable when the site gets upgraded

superswill
28-04-2008, 10:15 PM
might be doable when the site gets upgraded

the boss has spoken so its up to us

smpsmp45
29-04-2008, 06:16 AM
I am in too. We had a similar book mostly on AC etc. We need to have a similar compilation on Refrigeration.

nike123
29-04-2008, 06:52 AM
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.

;):):D

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.

superswill
29-04-2008, 07:51 AM
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.

;):):D

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

p_p
29-04-2008, 03:45 PM
Well put over superswill.


PP

cmac
29-05-2008, 10:13 PM
might be doable when the site gets upgraded

Just found this thread. sounds like a good idea.

Anybody want to start the ball rolling?

superswill
29-05-2008, 10:31 PM
iam up for it

Grizzly
29-05-2008, 11:02 PM
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

cmac
29-05-2008, 11:27 PM
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

Grizzly
30-05-2008, 07:38 AM
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

sabyashachibasu
30-05-2008, 12:40 PM
Thats cool.Pleas count me as i am a new

taz24
30-05-2008, 01:05 PM
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:p:p ONLY JOKEING....


Cheers taz.

Jadeair
30-05-2008, 01:11 PM
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.:D
Doesn't work all the time...

taz24
30-05-2008, 01:25 PM
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.:D
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.

Grizzly
30-05-2008, 03:18 PM
When rebuilding the compressor always throw a spare bolt in the sump. It gives the next engineer somthing to think about:p:p 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

taz24
30-05-2008, 03:28 PM
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.

Grizzly
30-05-2008, 05:07 PM
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.

Lippygit
12-06-2008, 09:19 PM
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 :)

Lippygit
12-06-2008, 09:24 PM
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 ?

sachin230
09-06-2010, 10:40 AM
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=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=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=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=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 (http://www.daikinaltherma.com:8080/SpaceAirSite/index_SA.jsp?mt=995&taxonomy_id=995&lang=en&site=995)

mikeref
18-08-2010, 12:36 AM
How about 65 btu/sq ft for home a/c where ambient can exceed 32c and insulation installed in the roof.

lice to chill
18-08-2010, 02:40 PM
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

lice to chill
18-08-2010, 02:42 PM
50/100 watts m2

glenn1340
18-08-2010, 11:02 PM
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.

glenn1340
19-08-2010, 09:01 PM
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.

amoureman
08-12-2010, 12:29 AM
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