Singaporeans Are Stuck with high Natural Gas Prices

24 Jan 2008 

Natural Gas prices dropped from US$12/= to about US$8/= whereas crude oil prices dropped less than 10%. It is time for Singaporeans to switch supplies from electricity or fuel oil to natural gas but we can’t. 

FAQ 

1. Why? 

Our two largest natural gas supplies, contracted by SembCorp in 1999 and Singapore Power in 2001 from Indonesia, are pegged to the fuel oil price for a period of 22 years and 20 years respectively. The last contracts will only expire in 2023.  These supplies are mainly for power generation.

 

http://www.geni.org/globalenergy/library/national_energy_grid/singapore/SingaporeCountryAnalysisBrief.shtml

Doubleclk to enlarge

2. Why the Peg? 

It is believed that the pegs were commercial decisions made during the signing of the agreements. Fuel oil prices stayed around US$20 per barrel for nearly 10 years when the agreement was signed in 1999/2001. The oil price hiked after 2003. 

3. What Happened to the Natural Gas Prices recently? 

Natural gas and oil are commodities traded at New York Mercantile Exchange(NYMEX). Natural gas price, determined mainly by supply and demand in the US, has been very volatile. The price dipped badly because there was more than usual natural gas inventory (supply) in the US. The mild weather in the US has less demand for natural gas. 

4. Does it mean that Singaporeans have been taken for a ride? 

Analysts believed the dip in natural gas price is short term because the fundamentals have not been changed; also, the lower price will reduce drilling activities and this will put pressure on the supply. They believe that the long-term natural gas price would stay tied to the fuel oil price. 

5. What happened to the Liquefied Natural Gas (LNG)? 

Singapore has planned to import LNG as an alternative source of supply but more for domestic consumption. She has appointed PowerGas to develop an LNG terminal in Jurong Island of Singapore. The details can be found here. 

6. Will we get Cheaper Natural Gas with LNG? 

Unlikely, not until we have competitions for the supply of LNG. In order to incentivize the LNG operators for their investment, the Singapore Government has regulated a new control i.e. no new license for natural gas supplier/operator. This control will not be lifted until the LNG’s consumption in Singapore has reached an acceptable level (3 MTPA or million tons per annum-see note) or after 2018, whichever is earlier. 

Conclusion 

Singaporeans are stuck with the present natural gas price that will be pegged to the fuel oil prices for a long long time. 

Note: Singapore presently requires natural gas, equivalent to about 7 MTPA of LNG, for her electricity generation, based on 3.3 MTPA per 2000 MW demand.

Heat Pumps for the First Wasteheat District Cooling System in Singapore

Heat pump works exactly the opposite of air-conditioner; it blows hot air instead of cool air. It has many industrial applications. This article describes how it could help to set up the first Wasteheat District Cooling System in Singapore.

FAQ
How Heat Pump Works?
In the nutshell, heat pump works exactly like air-conditioner but the opposite. One can find more information about it from Wikipedia.

Why Heat Pump?
Temperate countries use heat pumps for room heating but not so in tropical countries. It is 3 to 4 times more efficient than electric resistance heaters.
In industries, they are mainly used for:
a) Process heating and cooling;
b) Water heating;
c) Steam production;
d) Drying/dehumidification;
e) Evaporation;
f) Distillation;
g) Concentration
More details about heat pump applications in industries can be found here.

Proper use of heat pumps can save energy bills and cut environmental pollution. Payback is around 2 to 6 years. In industries that produce a lot of wasteheat, one can use heat pumps to convert them into useful energies.

3. How Much it Would Cost?
Heat pumps are basically refrigeration machine. It costs around US $2000/= per ton of refrigerant, slightly more than ordinary refrigeration machine. This cost is expected to come down by popular use.

4. What is the Largest Size Available?World’s largest heat pump can be found in Stockholm, Sweden. Vaertan e008 Uk It has 6 nos of 30 MW heat pumps. The total capacity of heat pump in the plant is 420 MW. . The heat pumps convert energy of sea water, a low grade heat much worse that wasteheat, into useful energy for district heating.

Heat Pump for Wasteheat District Cooling System (WHDCS)
One of the difficulties in setting up a WHDCS in Jurong Industrial Estate , is to secure wasteheat from the industrialists in Jurong Island. Many companies feared that the tapping of wasteheat, not being part of the design, might affect plant efficiency. The available wasteheat might not be able to start the WHDCS plant. If one has the heat pumps, one could supplement this wasteheat supply from seawater until more companies could offer wasteheat.

Conclusion
Singapore has no other resources but she has plenty of sea water. She should explore the use of this seawater not just for cooling purposes but also for extraction of its energy and water. Heat pump is one device that she could use. The use of heat pump could help her set up the first Wasteheat District Cooling system in this part of the World.

WasteHeat District Cooling System

A Concept Proposal for a WasteHeat District Cooling System in Singapore
22 Jan 2008

Introduction
Singapore imports almost all her energies; fuel oil from the spot markets and natural gas from Indonesia & Malaysia. About 20% of these energies are for cooling of buildings and almost all the cooling energies are generated from electricity. This article describes a concept proposal to tap wasteheat from Industrial plants to power part of the cooling requirement. It is meant for reference of those who are interested in the topic.

District Cooling System (DCS)Presently, Singapore has 2 running DCS plants, one in Changi Business Park and the other, in the Changi Naval Base. A few plants being planned; the larger one is for the Marina South Area. A brief description about DCS in Singapore can be found here.

The WasteHeat DCSSingapore has located energy guzzlers in an island called Jurong Island for strategic reasons, This island, about 2 km from the mainland, is a good candidate for one to tap and use the wasteheat for District Cooling. According to a conservative estimate, companies in this island are generating about 2000 MW of wasteheat and this energy can cool buildings in an area about 6 times the size of Jurong Industrial Estate.



FAQ
1. What is wasteheat?
Wasteheat are often referred to as low grade heat, not quite capable of being transformed into useful energy; thus, they are either vented into the good air by spending more energy cooling them or being dumped into the ocean.

2. Why Wasteheat?Wasteheat are not necessary free as there will be additional investment to extract them but they are much cheaper. The use would cut environmental pollution; help Singapore earn carbon credits and reduce her energy requirement. It could also promote development growth.
3. How could one tap wasteheat?There are few technologies available today to tap these wasteheat depending on their temperature. If one can get wasteheat above 120 oC, one can use absorption and/or Adsorption chillers to convert the heat into chilled water. If the wasteheat is less than 120 oC and above 60 oC, one can use desiccant cooling system.
4. How to transport the cooling energy to the mainland?It would not be wise to transport the cooling energy using ordinary chilled water because of the high pumping cost and the excessive heat losses. There are 2 other viable methods:
a) Slurry Ice method
Convert the energy to slurry ice or similar that can be transported over a longer distance;
b) The Desiccant methodTransform the heat into chemical energy using Desiccant. Then heat loss would not be an issue because desiccant is a chemical (e.g. Lithium Chloride) rather than an energy source; pumping demand would be much less as desiccant can “store” much more energy than water in any form.

Desiccant is preferred not only because the energy can be transported much further but also because desiccant cooling is more suitable for use in a very humid country like Singapore; it is more efficient than the electric air-conditioners in removing moistures from the air. Normally, air-conditioners in Singapore spend about 30 to 40% of the energy, removing these moistures.

5. What about viability?There was a research work indicating a wasteheat DCS in Jurong Island using absorption chiller method was viable; then, the electricity rate was about S$ 0.10 per Kwh, the fuel oil: US$25/=per barrel and the natural gas: US$ 6/= per MMBTU. Today, the electricity rate has almost doubled and the fuel oil, 3 times as much.

6. What is the Rough Cost of Wasteheat?It has been estimated that the wasteheat might cost about S$10 per MW. This rate is roughly 1/20 the cost of electricity at around S$ 200 per MW.

7. How Much Wasteheat could one tap?
Earlier work indicated an initial capacity of around 300 MW or 85,000 tons of refrigerant. This power will be enough to cool buildings in an area of about 2,000 ha or roughly the size of Jurong Industrial Estate.

8. What will be the Estimated Total Cost?Working on S$1,300 per ton, the estimated cost will be roughly S$100 millions excluding network piping which may be another S$ 200 millions.
9. What about Payback Period?
Working on very conservative figures, the payback period should be less than 8 years basing on today's energy cost

10. Can one start the DCS with a small plant?
Can we mix use different types of energy?
One can start a DCS at any size and slowly building them up over the years. There are DCS plants in the US that utilize small chillers in individual building, linking and integrating them over time to form a massive DCS network. Some of them mix use electricity, natural gas, diesel power and ground thermal heat to maximum profit.

11. What are the Expected Difficulties?There is no real technical difficulty. Tapping of wasteheat from Industrial plant for air-conditioning is well proven; however, there will be difficulties in securing wasteheat from the industrialists who must be convinced that wasteheat tapping, not being part of the plant design, will not affect the plant operation and efficiency. There was a concern of not having sufficient wasteheat to start up this DCS; however, this concern can be addressed by having supplemented heat from natural gas or seawater initially at a higher rate.

Why not much WasteHeat District Cooling found on the Web?Unlike Singapore where the energy guzzlers are located within distance, many countries locate their energy guzzlers remotely away from city centres. This concept will not work well for these countries because of the higher energy transportation cost. Most of them are small plants because of limited consumers; for example, this plant in Wakayama Marina City of Japan, has a capacity to heat and cool about 1500 homes and saved 30% energy bills.

Conclusion There should be no technical difficulties tapping wasteheat from the industries in Jurong Island for cooling purposes. There will be a need to convince the industrialists and secure the wasteheat from them. During the startups, the heat can be supplemented by natural gas or seawater. Singapore Government can help to promote this development.

Replacement of Car Engine Oil By Vacuum

Introduction
Sick of crawling underneath the car to un-tighten that nasty drain bolt to drain the engine oil? Think about using vaccum to suck out the engine oil instead ? This article tells how.

FAQ
1. How?Vacuum charged a container to suck out the engine oil from the oil dipstick hole. This hole is usually large enough to insert a flexible plastic tubing of size around 10-mm or ¼”.

2. Where Can I Find Vacuum Pump?
One can buy the pump from the store or just convert one from an electric tyre pump

3. How long it Would Take to Empty the Oil?Around 5 to 10 minutes depending on the size of the suction tube.

4. Would this Remove all the Spent Oil?It would remove the oil to an acceptable level. There were tests carried out to show that this method was better than the undercarriage draining method.

5. What’s Required ?a) A vacuum pump capable of pulling a vacuum of about 4 psi or 200 mm or 9” of Hg;
b) A home-made container.

6. How to Make the Container?
a) Pick a round metal tin, large enough to hold the engine oil; round ones can withstand higher vacuum pressure;


b) Find 2 Nos 25 mm long hard plastic tube to suit the size of the the spent oil and the vacuum flexible plastic tubing;
c) Drill two holes on top and at opposite ends for the 2 hard plastic tubes;
d) Apply epoxy glue to fix the hard plastic tubes in place and also the metal cover of the tin;
e) (Optional) For the level gauge, make 2 Nos of 90 degree bend; drill 2 holes at the top and bottom of the can; glue them in place and fit a clear plastic tubing connecting the 2 bends.

Draining Engine Oil1. Place the container close to the engine oil lipstick;
2. Connect up the 10-mm plastic tubing and insert it slowly into the lipstick hole until it has reached the bottom;
3. Hook up and turn-on the vacuum pump to start sucking the engine oil;
4. Meanwhile, carry out other chores like replacing the oil filters etc.

Note;
1. Empty the container from the oil inlet hole if necessary to prevent the overflow of the spent oil from reaching the vacuum pump.

Converting Tyre Pump to Vacuum Pump

Introduction
Want a vacuum pump? Have you ever think about converting the cheap tyre pump into vacuum pump? Here is how.

What is the use of Vacuum Pump?
One can use the vacuum pump for
1. Vacuum Sealing of food for packing and preservation;
2. Vacuum pressing of materials under atmospheric pressure; example, press sealing of veneer to a piece of plywood;
3. Vacuum replacement of car motor oil without carrying out undercarriage oil draining

What One will Need ?
1. A 12-volts electrical tyre pump
2. A short length of pressure hose
3. A hose clip
4. Some Epoxy glue

The 12-Volts Tyre Pump
One can find the cheap 12-volts electrical tyre pump in practically every store. They are small but yet powerful to inflate tyres. Some of them are capable of delivering more than 200 psi of pressure.

They are never designed to be vacuum pump but the piston construction of which make them candidates for conversion into vacuum pumps.

Find a tyre pump that has suction hole as shown attached. There are some that do not have these features.

The Construction of the Pump
The Tyre pump consists of 4 components
a) The 12 volts electric motor
b) The gearbox
c) The piston
d) The discharge and suction valve

The Conversion Work1. Cut a piece of tube of about 40 mm long;
2. Carefully insert the tube just to cover the suction holes of the compressor;
3. Use small amount of quick dry cement to secure the tube in place first, then use high temperature epoxy glue or just ordinary or steel epoxy glue to fill the gap and build the mount to secure the tube. If necessary, reinforce the tube by tying the tube to an attachment of the pump and fill them all up with the epoxy glue.
4. Insert the hose and clip after the the glue is dried. Reassembled the cover in place.

Limitations1. The pump is not designed for prolonged operation. Operation of more than 20 minutes might seize the piston as excessive heat would build up;
2. The pump can only pull a vacuum of about 20 to 25 inches of mercury. Not necessary suited for use in car air-conditioning repair work;
3, It draws about 4 amperes of current from a 12-volt DC source.

Repairing Car Air-Conditioning system (Part 3)

Charging Car Airconditioning System

Jump to
1. Vacuuming
2. Charging up
3. Testing and Commissioning
4. Repairing Airconditioning (Part 1) 
5. Repairing Airconditioning (Part 2)  

Introduction  

One has located the leak. This article will describe how to replace the component and charge the system with Freon gas

FAQ

What do I need?

Besides having to buy the replacement spares, one would need:
a) a set of new O-rings for the joints. Ask the shop owner for them to be supplied correctly if the spares do not come in a complete set. There are different sizes of O-ring for different parts;.
b) A new filter/dryer. Take the opportunity to replace the filter/dryer if it has not been replaced after some operation;

Preparation

Make sure one would have the following things ready as they would be needed after the repair unless one is to send the car to a workshop for charging up the Freon:-

a) The high/low-pressure gauge (or manifold gauge);
b) The vacuum pump;
c) The compressor oil ;
d) A tank of the correct type of Freon.

Next Step 

1) Replace the faulty component as required. Replace also the O-rings;
2) Replace the filter/dryer after removing the existing pressure switches and/or pressure relief valve if any and reinstall them in the new filter/dryer. Replace the O-rings as necessary;
3) Make sure the components are all in place and one is now ready to charge the system with Freon.

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Vacuuming 

Since the Freon has been discharged, one would expect air trapped inside the system to be removed by vacuuming;.

1) Hook one end of the low-pressure hose (blue) to the nipple valve that is attached to the suction pipe of the compressor. Hook the other end of the yellow hose(yellow) to the vacuum pump’s nipple valve. Before starting the vacuum pump, ensure that the operation valve of the suction pressure is left fully open (valve underneath the blue gauge);

2) Allow vacuum pressure to go up as high as possible. Normally, it should be more than the water boiling point pressure; for example,
water will boils @ 80 degreeF @ vacuum pressure of -29 inHg

3) Shut off the vacuum pump and allow the pressure to stand for about 30 minutes and observe the pressure. If the repair is effective, the pressure should stay at the same pressure without any loss in pressure; otherwise, suspect a leak in the repairs. Use soap detection method to detect any leak if necessary.

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Charging up

If the repair is effective, the system will be ready to be charged up the Freon.
1) Close all valves on the pressure gauges. Remove the yellow hose from the vacuum pump but do not remove the blue hose that is already connected to the suction end of the compressor;
2) Charge compressor oil into the yellow hoses or use a proper oil injector to charge. The amount of oil to be charged will depend on the type of repair or oil leakage. Normally, assume 80% will be lost if one drained the compressor empty; otherwise, assume about 15-20% loss in oil. For information, a car air-conditioning system would normally have 300-350 cc of oil; 
 
3) Remove all other attachments and tools from the engine compartment;
4) Startup the engine and run it at idling speed; ensure that there is no unusual noises; otherwise, stop the engine and investigate;
5) If all is well, open the valve at the Freon Tank first. The blue pressure gauge should hit around 70 psi. Now turn on the valve at the suction end of the pressure gauge (blue). The pressure should drop quickly as the valve is being opened;
6) Control the valve such that the suction pressure would stay in the range of about 30 psi to 35 psi; do not let the pressure goes above 45 psi;
7) Observe the sight glass on the filter/dryer. If the Freon is not adequate, the sight glass window will be whitish in color, caused by the bubbling of Freon. Further addition of Freon should clear the bubbles especially when one rev up the engine a little.  

On the occasion that the sight glass window is still whitish or the Freon bubbles are still visible after some time of charging, suspect some trouble with the system or the compressor.





Under normal operating conditions (not charging),  one would expect some bubbles at the sight glass when the engine is idling. The bubbles will increase as the engine is rev up.  

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Testing and Commissioning

Do a test on the air conditioning system, the air vent should now blow cooler air if the repair is effective and the system is fully charged up with Freon. To ensure proper work is done;
a) make sure the engine and air-conditioning are running smoothly;
b) Check the area of repair for a possible leak using a gas detector or just plainly, performing a soap bubble test;
c) Check that the pressure gauges stay within range, with suction or low pressure around 30 -35 psi; if needed be, hook up the red hose to the discharge nipple of the compressor, one would expect a reading of around 200 psi depending on the type of Freon and the ambient temperature.

Other Related Sites

1. Car Aircon Compressor Repairs
2. Car Air-conditioning Part 1
3. Car Air-conditioning Part 2
4. Car Freon Charging for Novice
5. Car Safety Inspection and Check at Home
6. Replace Engine Oil by Vacuum
7. Wheel Alignment Using Sideslip meter

Repairing Car Air-conditioning (Part 2)

Car Airconditioning Gas Leak Detection


Jump to
1. Problems in leak detection
2. Gas Detection Instrument
3. Car Air-conditioning Part 1
4. Car Air-conditioning Part 3

Introduction

This part 2 series will describe how one could locate the Freon gas leakage. This is by far, the most common type of fault in car air-conditioning systems.

FAQ 

Why Freon Gas Leaks? 

Freon, in the process of compression and expansion, creates high pressure especially when it is operating under the hot sun. The pressure puts stresses on piping joints which are sealed by O-rings. These O-rings, made of rubber, can deteriorate with time and become deformed. Sometimes, the pressure could also cause a hairline crack in pressure switches or the expansion valve. However, most Freon leakages are found in corroded tubing inside the evaporator because most of these tubing is made from flimsy aluminum materials for some reason.

What Special Equipment Required?

 Normally, one can detect the presence of Freon gas leakages without any special equipment although a gas detector would help.

What Else Do I Need to Know 

Safety requirement. Read all about how to make the environment safe for one to inspect and repair the system.

Preparation 

1. Switch off the engine;
2. Locate the pipes and other air-conditioning components and pay particular attention to the location of piping joints and the weaker components with plastics such as pressure switches. Normally, these components are located in the engine compartment; only the evaporator and the expansion valve are located in the car compartment.

Next Step

1. Use the torchlight, inspect every joint and component for evidence of oil leakage. Special oil used for lubrication of compressors is often carried away by Freon and gets circulated in the system during the operation. Oil will leak when there is Freon gas leakage. The trace of oily patches will often give the location of the leak;



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Problems in leak detection 

There will be times when the simple surface inspection failed to locate the leak. This is because the leaks are sometimes located out of sight; for example, in the evaporator compartment or at the compressor.
For the leak at the compressor, one should be able to use the hands to “feel” the excessive oil from the bottom surface of the compressor. As for the evaporator, it will be hardly noticeable although there might be some minute traces of oil in the condensate pipings at times.
Sometimes, leaks are so minute and gradual that it leaves no trace of oil to tell the location of the leak; then one would require the use of a proper Freon detection instrument. In this case, a good charge of Freon is often necessary to detect the leak and the air-conditioning system will need to be in operation.


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Gas Detection Instrument

There are basically 3 types or methods. The use of the electronic instrument, the gas burner, and the soap bubble method.
The electronic gas detector may cost around US$ 100-$ 200 and would require regular calibration and maintenance but it is safer to use. The electronic detector usually samples the air at a rate of about 1500 times per second and give an alarm if any halogenated refrigerants is detected. Sensitivity is around 0.1 oz/yr or 3 gr/yr.
The gas burner method is commonly used by mechanics in the older days and is still in use today.
The burner type is less sensitive and the detection is by observing the color of the flame. Normally, on detection of gas, the flame would turn bluish-green for small leaks and bluish violet for larger leaks.

The soap bubble method is one of the oldest and easiest methods being used even today. It is a very rough method and less accurate and also, one would need to know roughly the location of the leak. It could be time-consuming and works only on exposed components or piping joints.

Other Related Sites
1. Car Aircon Compressor Repairs
2. Car Air-conditioning Part 1
3. Car Air-conditioning Part 3
3. Car Freon Charging for Novice
5. Car Safety Inspection and Check at Home
6. Replace Engine Oil by Vacuum
7. Wheel Alignment Using Sideslip meter

To Embed Automated Gifs in Blog/Websites

Introduction
Bloggers cannot embed automated GIFs in their articles because blogspot will convert them automatically to JPG. This article tells how to embed such automated GIF in a simple way.

What you will need?
Open a free account with PhotoBucket or any other server that one can use their scripts to download the GIF

Next Step
1. Upload the automated GIF to the PhotoBucket through this screen


2. One would soon see the GIF if one has uploaded the GIF successfully;

3. Now, copy the little html code to embed in the blog pages. There are 2 ways to copy the html code:

a) copy the code directly from the "HTML Code" shown beneath each GIF picture
The result is a GIF picture of original size. The GIF will be trancated if the GIF is of too big a size.

b) Select the button: "Generate HMTL and IMG code" and one would be greeted by the follow screen:




Select to copy the code either for displaying a thumbnail or a GIF of original size. Preview if necessary. To prevent GIF from trancated, it would be necessary to use thumbnail version for the side bars.

4. Place the copied code in the "Edit Html page" (Not Compose page) at a location where one wants the GIF to appear and Presto! one got the animated GIF embedded in one's website or blog.


5. If one prefers to embed the GIF in the side bar so that it could be displayed in any page of the blog, just follow the following instructions:


a) Goto the layout page and in the "Add and Arrange Page Element", select "Add a Page Element" then
b) In the "Choose a New Page Element" screen, select "Add HTML and JavaScript" and finally, add the html code in space provide as shown. Save changes and view the blog for results.

Repairing Car Air-conditioning (Part 1)

1. How Air-conditioning works?
2. The Special Tools and Equipment?
3. The Professional Must Owned Equipment?
4. The Professionals Verse Non-Professionals
5. Repairing Car Air-Conditioning (Part 2)
6. Repairing Car Air-Conditioning (Part 3)

Introduction

The Air-conditioning system of one's car started to blow hot air or one found frost in the evaporator. What went wrong? Part 1 of the article describes how the car air-conditioner works and what special equipment will be required to carry out the necessary inspection and repairs.

FAQ

1.. How difficult to troubleshoot and repair?

 If you are not a handyman type, it could be difficult as one might have to dismantle the mechanical components, and might have to crawl underneath the car to carry out the necessary inspection and repairs;

2. Do I need special tools and equipment? 

Yes. One would need at least high and low-pressure gauge to perform simple work such as inspecting if there is enough gas in the system and charging up the Freon;

3. What other material is required? 

To top up the Freon, one would need a small tank of the correct type of Freon, either R12 for the older cars or R134 for the newer cars. There is also a need to have the special grade of compressor oil ready in hand. To repair the air-conditioning, one would need to have a vacuum pump besides having the necessary replacement parts and the O-rings to seal the joints and pipes. As for the Professionals, they may have owned also the flushing and the Freon recovery system.

4. Can I DIY this special equipment also?

Yes. There are websites that describe how to DIY this equipment using simple and cheaper equipment but proper equipment is required for that serious mechanic who would want to do a good and lasting repair job.

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How Air-conditioning works

Air conditioning works primarily on the principle of evaporation. Much like humans feeling the cooling when water evaporates from their skin; except, in air-conditioning equipment. the evaporation process is carried out at a very very much faster rate.
The media being used in most air-conditioners or refrigerator alike is a gas called Freon. The older car used Freon R12 which has now been phased out by Freon R134 because the latter is ozone depletion free.

Doubleclick to expand the picture

The air-conditioning system for the car has about 5 major components as shown attached. The cooling process starts at the compressor. The Freon is first compressed from gaseous state to liquid state to a pressure of about 90-180 psi (600 -1200kPa), depending on the cooling requirement and the ambient temperature. Freon gets heated during this compression process and must be cooled by a fan(usually electrical or mechanical) in the condenser (the heat rejection). The liquid Freon, after being filtered by the filter/dryer, will expand quickly into the evaporator through a metered orifice called the expansion valve. This sudden expansion of the liquid Freon into a bigger evaporator chamber causes "violent" evaporation of Freon. This expansion process turns Freon from a liquid state to a gaseous state and picks up the heat from the car compartment (heat absorption). The gaseous Freon is then sucked back into the compressor at a pressure of about 30 psi (200 kPa). The cycle then repeats.

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The Special Tools and Equipment

I) The Basic and Must-Have Equipment

1) High/Low-Pressure Gauge with Manifold

a) The tool is as shown below

Doubleclick to enlarge the picture

The gauge has the following components
a) 2 pressure gauges, one for measuring high or Freon discharged pressure (red in color) and the other is for measuring the low or Freon suction pressure (blue in color)
b) A manifold with 2 control valves to close the release of the Freon gases
c) 3 connection hoses, one to connect to the compressor outlet and the other to connect to the compressor inlet. The yellow one is for connection to the Freon gas tank.

2) Freon

The Freon is usually sold in a cylinder tank of about 25 lbs in weight. The commercial ones come in industrial cylinders whereas the hobbyists may buy them in canisters.

The Must-Have Equipment for Repair Work

1) Vaccum Pump

One would need the vacuum pump to remove the air as well as water vapour trapped in the air-conditioning system after every repair job. Air and water vapour not only take up unnecessary space, but they are harmful also to the compressor. Normally, water will boil at room temperature of 25 degreeC when the vacuum pump reduces the system pressure to 25 mm of Hg. The vacuum pump should be left long enough (15 to 30 minutes) to remove all possible traces of moisture.
The vacuum pump should be capable of pulling at pressures twice the boiling point of the water or around 1 atmospheric or 760 mm or 29” Hg pressure.

2) O-rings and Replacement Spares

Faulty parts are often replaced than repaired. This is because many parts are not repairable. When purchasing replacement spares from the shops, ask also for replacement O-rings. Discharge the old O-rings as these are often deformed after use.

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The Professional Must Owned Equipment

1) The Air-conditioning Flushing System

The purpose of flushing is to remove oil and debris in the system. Very often when the compressor seized up, it generated a fair amount of metal chips or debris which are trapped in the system, especially in the evaporator. If this debris are not removed, it will damage the replacement compressor.

The Professionals are seen to own and use such a piece of machine because the machines are not only expensive but also require frequent maintenance. The non-Professionals often do away with flushing totally or just flush them with mineral spirits or just petrol, utilizing compressed air to charge in the liquid as well as to dry and empty the cleaning fluid.

The Regulatory Equipment

1) Freon Recovery Equipment

Some countries, like the United States, have mandatory requirements for Freon to be recovered in order not to pollute the environment; however, many other parts of the World, especially in 3rd World and Asian countries. Mechanics have been seen to vent the Freon into the good air.

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The Professionals Verse Non-Professionals

In countries that do not regulate car air-conditioning repairs, one would often find many non-professional setting up shops offering different rates for their services.
These non-professionals do not necessarily offer lower rates for the repair and servicing work; however, their work can do more harm than good to the car air-conditioning system. It is also good to be aware of such repair shops.

These shops often do not own the necessary equipment such as the flushing system. They also never renew their old and broken-down tools and equipment. Many a time, one would find the pressure gauges with broken glasses, tubes full of grease and dirt, and vacuum pump with either broken down pressure gauge or without any pressure gauge at all.
This non-professional would often ignore oil losses when charging the Freon and one would not normally realize until the compressors started to make noise a few months' time; by then, a replacement is required.

The author has been often "cheated" by these non-professional shops and therefore, writes this article for the benefit of the car owners

Other Related Sites
1. Car Aircon Compressor Repairs
2 Car Air-conditioning Part 2
3. Car Air-conditioning Part 3
4. Car Freon Charging for Novice
5. Car Safety Inspection and Check at Home
6. Replace Engine Oil by Vacuum
7. Wheel Alignment Using Sideslip meter

Home Made Food for the Koi Fishes

IntroductionWe kept 10 Koi fishes in our indoor pond; 8 of them survive for more than 10 years. We rear them from about 2 inches to more than 22 inches today. When they were tiny, we feed them with pellets. As their appetites grow, we prepare home cook meals. This article describes the few methods we used to feed these fishes.

Nutrition and Vitamins
Fish needs nutrition and vitamins to grow and survive; so, there is a need to feed the fishes with several different kinds of food.

Types of Food
At different occasions, we feed them with different food:
a) When we are in hurry, we feed them with pellets or just plain slide of bread; sometimes, we feed them with dried small fishes or shrimps we bought from the market;
b) When we have a little more time, we feed them with hard boiled egg or we just mix the raw egg with some dried small fishes or shrimps or sometimes, the pellets and fry them into a pancake, then cool it with water before feeding;
c) When we have more time, we prepare cookies. In here, we mix pellets, any leftover biscuits and other dry foods such as dried small fishes or shrimps and then blend them into powder. Finally, we mix the ingredients with raw eggs and hand mix them until they can be made into nice small balls for refrigeration. Make the balls large enough so that each ball is enough for one feeding.

Things to Observe When preparing the Food
a) There is no single nutrient that is capable of satisfying all the nutrient requirements of Koi. These nutrient requirements can only be completely met by blending various raw materials;
b) Test the food each time in small quantities when you mix and prepare new formulas. The food should be consumed within 10 minutes for each feeding. The fish may not like the new ingredients. Left over, if any, will quickly degrade the water quality;
c) The filtration system must be good enough to take all the food that you have just thrown into the water.

Important Observations
Koi fishes, like any other animal, are always:
a) Hungry at food feeding time; they would respond actively and swim faster than normal when one approaches the pond. They would take no more food when they are full. Feed them once or twice a day, and;
b) Actively swimming around, except during the night when they would stay quietly; if they are not active, it is time to investigate as they may be sick, requiring medical treatment;

The Koi fishes will always tell you when they are uncomfortable. They will be nervous and keep jumping out of the water often; at times, they may even jump out of the pond. It will then be the time to investigate the causes. The water quality would be the first to be suspected; there may be other causes that might have threatened the living condition. Check the water pump for reduced water flow or stoppage. Reduce the food consumption or increase the filtration capacity to suit the size and number of the fishes in the pond or the aquarium.

Other Observations
a) Kois can learn. They are timid at first when we have them. Always grouped and stayed away from us even when they are hungry. They would only take the food when we are away. This lasted few months until they started to take food away from our palms.
b) Kois are cleaners. They would clean up every bit of food they can find and the water in their area will always be cleaned. Dirt, if any, will be pushed away to one corner for easy siphoning. When we give them the right mix of food, we could hardly find any dropping. They would chew every bit until it is fine enough to be cleaned up by the filters.

End Note
With sufficient and effective biological wet and dry filtration system, we only clean our filters once every two years or when we need to repair the filtration system. We top up the water through a small dripping feed pipe and we provide an overflow drain pipe to maintain constant water level. We have never change the water since we set up the indoor pond 10 years ago.

We used simple and cheap materials for the construction of the filtration system and made the water to clean itself over and over again before returning back to the pond. We will write about the filtration system and the indoor pond construction if there are interests.



Note: Sorry about the picture quality... will update when I got another good camera,