How Air Conditioners Work

Submitted by: P Hunter

Cooling is the transfer of heat energy via radiation, conduction or convection. But how does cooling really work in air conditioning systems.

Air conditioning cooling systems take advantage of a very clever physical law. When a fluid converts to a gas, it absorbs heat and conversely, when a gas converts to fluid, it releases heat.

Air conditioning systems use these principles over and over again to move heat from one location to another (e.g. from indoors to outdoors). In very simple terms, they use a closed loop of pipes to circulate a compound. Within this system is a compressor to convert the compound to a gas (therefore absorbing heat) and an expansion valve to convert it back to fluid (releasing heat). It s a little more complicated than that, but if you keep that simple concept in mind when reading the rest of this article.

Before we move on, just to let you know the compounds cooling systems use are known as refrigerants which have special qualities that allow them to change from fluid to gas (and vice versa) at much lower temperatures, thus better facilitating the cooling process. So here goes in a bit more detail:

1. When hot inside air flows over the cold, low-pressure inside evaporator coil (more commonly known as the inside air handling unit), the refrigerant inside absorbs heat and as it does so, it changes from a fluid to a gas.

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2. To keep cooling efficiently, the air conditioner has to convert the refrigerant gas back to a fluid again. To do that, a compressor puts the gas under high pressure, a process that creates unwanted heat.

3. All the extra heat created by compressing the gas is then evacuated to the outdoors with the help of a second set of coils called condenser coils, and a second fan. As the gas cools, it changes back to a fluid.

4. The fluid refrigerant runs through an expansion valve, and in the process it evaporates to become a very cold, low-pressure gas. This is feed back into air handling unit and the process starts all over again.

It’s easy to see that there are two distinct things going on in an air conditioner. Refrigerant is chilling the indoor air, and the resulting gas is being continually compressed and cooled for conversion back to a fluid again.

Now lets look at the various components of a cooling air conditioner in more detail:

The compressor (which is controlled by the thermostat) is at the ‘heart’ of the system. It acts as the pump, causing the refrigerant to flow through the system. Its job is to draw in a low-pressure, low-temperature, refrigerant in a gaseous state and by compressing this gas, raise the pressure and temperature of the refrigerant. This high-pressure, high-temperature gas then flows to the condenser coil.

The outside condenser coil is a series of piping with a fan that draws outside air across the coil. As the refrigerant passes through the condenser coil and the cooler outside air passes across the coil, the air absorbs heat from the refrigerant which causes the refrigerant to condense from a gas to a fluid state. The high-pressure, high-temperature fluid then reaches the expansion valve.

The inside evaporator coil is a series of piping connected to a furnace or air handler that blows indoor air across it, causing the coil to absorb heat from the air. The cooled air is then delivered to the house through ducting. The refrigerant then flows back to the compressor where the cycle starts over again.

The inside Air handling Unit of an air conditioner contains the evaporator and a fan that blows air over the chilled coils and into the room. The outside part of the air conditioning unit contains the compressor, condenser and another fan to vent hot air coming off the compressed refrigerant to the outdoors.

In between the two sets of coils, there’s an expansion valve. It regulates the amount of compressed fluid refrigerant moving into the evaporator. Once in the evaporator, the refrigerant experiences a pressure drop, expands and changes back into a gas. The compressor is actually a large electric pump that pressurizes the refrigerant gas as part of the process of turning it back into a fluid. There are some additional sensors, timers and valves, but the evaporator, compressor, condenser and expansion valve are the main components of an air conditioner.

Described above is a conventional setup for an air conditioner and it is known as a split system.

About the Author: Peter Hunter is a Director at

Air Intelligence Ltd

. With 25 years expereince, they are leaders in the provision of commercial air conditioning and commercial heating through London and the Home Counties. Locationed in Berksire (see

Air Conditioning Berkshire for details



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Methane gas explosion at Ulyanovskaya Mine kills at least 108

Monday, March 19, 2007

A methane gas explosion occurred at the Ulyanovskaya Mine near the city of Novokuznetsk in the Kemerovo region of Siberia. At least 106 people have been reported to be killed in the blast. Conflicting reports say that at least thirteen to forty-three miners are still trapped underground or missing, as well as 75 to 93 have been reported to have survived the blast.

The mine disaster is the deadliest accident in Russia’s mining industry in over a decade. The mine, which was opened in 2002, had around 200 miners inside at the time of the methane gas explosion.

The Kemerovo governor Aman Tuleyev said that when the blast occurred, the mine’s management was underground inspecting a newly installed safety system made by a British company. British experts and representatives of a management of the mine have gone down under the ground shortly before explosion. Tuleyev stated that on mine start-up, “the newest English system on a safety of conducting mountain works under the ground” should take place.

The operator of the mine is Yuzhkuzbassugol, Russia’s biggest producer of deep-mined coal. The spokeswoman of the Emergencies Ministry stated that the blast occurred at 08:00 GMT, and that eighty-three miners had been safely evacuated from the mine shaft.

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Open source game developer Perttu Ahola talks about Minetest with Wikinews

Tuesday, June 30, 2020

Recently, Finnish open-source video game developer Perttu Ahola discussed Minetest, his “longest ever project”, with Wikinews.

Started in October 2010, Minetest was an attempt by Ahola to create a sandbox game similar to Minecraft. Minecraft is a multi-platform commercial game, which was in alpha version when Ahola challenged himself to create something similar to it from scratch, he told Wikinews.

Minetest is an open-source game, which is free for anyone to download and play. It is written in the C++ programming language, and the source code is available on code-hosting site GitHub. According to Ahola, Minetest attempts to run on older hardware, with limited graphics, but to be accessible to more people: those who have outdated technology, and making it available for no cost. Minecraft, on the other hand, is a paid game, currently costing USD 26.95 for its computer version. Minecraft is currently owned by Microsoft, and performs poorly on older hardware.

A correspondent from French Wikinews contacted Perttu Ahola via Internet Relay Chat a few weeks ago, discussing Minecraft. This interview is built on top of the previous interview, as we take a deeper dive into knowing more about this free game which is about to turn ten years old in a few months.

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Signs You Need To Call An Emergency Plumber In Washington Dc

byAlma Abell

Most homeowners tend to take their plumbing for granted. Their toilets and drains work without issue and water appears when a faucet is turned on. However, when the wear and tear on the pipes and the drains become clear, homeowners may experience a feeling of panic. Some signs that your plumbing may be in some trouble and you could benefit from the services of an Emergency Plumber in Washington DC are highlighted here.

A Never-Ending Drip

A faucet with a slow drip is something that many homeowners are able to live with. However, if you ignore the issue, it can lead to a large amount of wasted water and result in higher water costs. Smaller leaks may be the symptom of some other type of plumbing issue. Most leaky faucets can be easily fixed by any do-it-yourself homeowner. However, if you need to know what caused the leak, you should call on the services of an Emergency Plumber in Washington DC to find the problem.

A Drain that Stops Working Properly

If you have a tub or sink that does not drain properly, this can be the result of some type of blockage. There are a number of products that are designed to break up this blockage and clear any type of stopped drain. However, if you overuse these over the counter chemicals, they may cause substantial damage to your pipes. If you have a recurring or stubborn blockage, then you may need to call in a professional who has the right tools to fix the issue for good.

Trouble with Your Toilets

Toilets can often become backed up. The sewage lines can become stopped up or, in some cases, there may be a blockage that will be able to be quickly cleared with a plunger. Some more serious issues may exist as well. For example, if the blockage occurs often, or if the toilet bowl begins to fill too high or the water level in the bowl is too low, it is time to contact a professional.

When you know what to look for, you will be able to call on the services of a plumber before the problem becomes worse. If you would like more information regarding your plumbing, visit website. Then you can call a plumber when the needs arise.

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There Are Many Healthy Diet Foods And Snacks For Dieters}

There are Many Healthy Diet Foods and Snacks for Dieters


markus duval

When you are on a diet, you can find occasions when hunger strikes and you require a low calorie, wholesome snack. Low-fat foods and foods with dietary fiber help fill the stomach and end cravings. Wait 20 minutes after eating, as that’s how long it requires your stomach to inform your brain that you’re full. Be particular that you’re experiencing hunger, and never consuming for emotional causes.

Raw vegetablesRaw veggies are full of fiber and antioxidants. Keep sliced vegetables chopped and prepared to snack in the fridge for the quick and easy snack.Frozen BananasA banana cut into bite-size items is quite a filling snack, and is a mouthful of flavor in just several calories. Coat the banana pieces in melted chocolate and cool on a cookie sheet before freezing for the real deal with!ChocolateChocolate is a wholesome food with great fats and loaded with antioxidants. A small piece of healthy chocolate- natural, cold pressed or raw- can satisfy the craving for candy, whilst nevertheless supplying a sweet treat.Sliced ApplesAn apple contains one of the best types of fiber. They are easy to digest and make a refreshing treat. Applesauce is another good alternative. An apple is easy to transport and doesn’t require refrigeration.PopcornAnother high-fiber food is popcorn. You can buy low-fat varieties, or pop it yourself.GelatinMake your personal jell-o with gelatin and fruit juice. Apple juice and grape fruit are each scrumptious. You’ll fill your abdomen with a lower calorie food and you might grow much better hair and nails from the protein within the gelatin as well.Frozen PopsiclesMake your own berry juice popsicles. This can maintain you hydrated in hot summer months and supply a refreshing way to cool down and fill up.Consume WaterBefore a meal, drink drinking water to fill your stomach. Hydration is important to wellness and to fat burning metabolism.Fruit SaladFresh fruit with lemon juice will keep in the fridge for as much as 24 hours and provide a nutritious and filling snack.Plan your snacks in advance. Lower vegetables and have them ready in the fridge. Pre-package popcorn or nuts in little bags, so that you will eat measured quantities and never get carried away.Permit yourself to snack by snacking on wholesome foods choices and you’ll lose pounds without feeling deprived. Great nutrition and healthy food options are usually the best way to ensure you’ll stay slim and fit.

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There are Many Healthy Diet Foods and Snacks for Dieters}

Millions of old New Zealand coins still to be handed in

Wednesday, October 25, 2006

On November 1, 2006 the old five, ten, twenty and fifty cent coins will be illegal tender, but the Reserve Bank of New Zealand says there are still at least 100 million still to be returned.

According to the Reserve Bank, most of the old coins have been lost in drains or buried in rubbish. “We think there is still another 100 million sitting around in people’s homes,” Brian Lang, currency manger for the Reserve Bank, said.

Lang said: “So far, just over 280 million coins have been returned, but there are more out there. Since 1967 the Reserve Bank has issued more than a billion of the old ‘silver’ coins. So if you don’t want to be stuck with loads of old coin – there’s never been a better time to empty your coin jars, sweep the car glove box and rummage behind the couch cushions.”

The coins still awaiting to be handed in, by either spending them, taking them to a bank or donating them to charity, are estimated to be worth between NZ$5 million and $50 million.

“A last-minute burst of publicity may convince people to bring the coins in. It’s a bit of a hassle though. Human nature being what it is, people just don’t care,” Lang said.The Karori Wildlife Sanctuary located in Wellington say that they have collected over $9,000 in old coins. Sanctuary spokesman, Alan Dicks said: “The campaign was particularly fitting because the old coins depicted tuataras and kiwis, both of which can be found living at the sanctuary. The money will go towards supporting general ecological restoration of the sanctuary. We want to get over ten grand, but the more the better.”

Lang said: “Though the coins will no longer be legal tender, banks will continue to exchange them until at least the end of the year,” and the Reserve Bank will always exchange them. “We are still getting people coming in with two-dollar notes,” Lang added.