HVAC Systems



             


Wednesday, February 13, 2008

High Velocity Air Conditioners

High velocity air conditioners work by delivering air into a room at a high velocity (roughly two feet per second). This creates air currents that circulate cooler air throughout the room or entire house.

The high velocity systems have certain advantages and disadvantages over the conventional forced air system. For example, the conventional systems moves air slowly. You really don't feel the circulation and there can be dead spaces in rooms if vents were not placed properly. High velocity systems places vents in more locations; thus, there is a more consistent airflow and temperature throughout the house. However, since conventional systems use larger ducts, more air passes through and they are silent. The high velocity systems use much smaller tubes to circulate air and are nosier. Conventional systems are also easier on your pocket, as tend to last longer because of the metal ductwork, etc. High velocity tubing deteriorates more often than metal ducts and tubing causes stress on the mechanical components of the unit.

On the plus side, conventional systems are more visible in the home than the high velocity. Conventional systems require more space because of the larger vents, and every room needs a supply and return. The high velocity unit requires much less space and can be set up in one area for the supply and return requirements. Also, the high velocity system is less expensive than the conventional one.

Finally, keep in mind that central cooling systems are not easy to install. There is generally a problem with any installation. Any errors in installation can cause major problems and a major impact on your electric bill. Make sure you get plenty of bids and pick a contractor that you have faith in. The contractor should be experienced and offer you references to check out the work that has been done.

Air Conditioning provides detailed information on Air Conditioning, Air Conditioning Repairs, Central Air Conditioning, Auto Air Conditioning and more. Air Conditioning is affiliated with Chiller Rentals.

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Monday, February 4, 2008

Mechanical Air Conditioners - Part I - Operating Principle

Mechanical air conditioners form the largest population of AC in this world. This article will go through the simple operating principles of this AC type. Additionally, we'll also go through other AC types used in commercial world. Namely, these are gas absorption, steam based, and thermoelectric units.

Common ACs, that we see almost everywhere on this globe, is actually, the mechanical type of AC unit. If we were to be very meticulous in the naming structure, we would have called it Mechanical ACs.

However, we just name it as air conditioner, or ACs, and everyone understands it.

One should not confuse the term between, air conditioning, and AC. Air conditioning means altering temperature, humidity, air filtration, movement and mixing. Whilst ACs are the equipment used to alter the temperature and humidity - in one package.

There are four types of ACs available for us. The,

  • gas absorption AC,

  • steam based AC,

  • thermoelectric AC, and

  • the mechanical AC

The first three AC types are mainly (if not totally) used in industrial applications. We'll go through the air conditioner operation, briefly, before concentrating on mechanical air conditioners.


Gas absorption AC

Uses, water as its refrigerant. The system uses the principle of vacuum, to encourage boiling of water at very low temperature. The water will be passed through cooling coil, for producing cool air.

Lithium bromide will be used as the absorption (or recovery) medium, once the water has passed through the cooling coil.


Steam based ACs

Is similar to gas absorption units, but it uses the brute power of steam, and venturi, to reduce the pressure of water (which is the refrigerant).

Water at low pressure will boil at low temperature, and becomes a refrigerant.


Thermoelectric AC

This AC uses the principle of thermocouple to attain heating and cooling effects at the same time. The beauty of this system lies in its simplicity of construction.

It uses electrical power, and thermocouple. As the electricity flows through the circuit, you'll get a hot region, and a cold region. Talk about killing two birds with one stone.

However, the major limitation of this concept is that, it can only produce a small cooling or heating effect, compared to other air conditioners.


Mechanical Air Conditioners

It is named mechanical, as it requires the continuous act of refrigerant compression for cooling, or heating effect. This concept was thought by Willis Haviland Carrier, when he created the first mechanical air conditioner.

Special refrigerant are used in order to achieve this. These are known as CFCs (already banned), HCFCs and, HFCs. Why use these? Because of very low boiling temperatures, at ambient pressure.

Details of this air conditioner operation,

  • a compression process is required to raise the pressure of refrigerant. When this happens, you can liquefy the refrigerant (through condensation) easily,

  • this is followed by refrigerant condensation. Condensation happens through heat exchange between refrigerant, and air (or water),

  • an expansion device (or valve) will be placed after the condenser. This is a device to allow for pressure build up from compressor. This is also, the place where refrigerant will evaporate into low pressure region.

    When this happens refrigerant will start to boil at very low temperatures,

  • finally, the refrigerant will be passed through another heat exchanger - to complete the boiling process. Heat exchange happens between air and refrigerant

  • this process repeats at the compression side

Those are the processes involved in achieving cool air, through mechanical air conditioners - through continuous "supply" of refrigerant at low temperatures.

Part II is coming soon...

TS Mohamed Rasied,
Provides information on air conditioners and air conditioning in her site,
http://www.air-conditioner-selection.com/
 

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Saturday, January 19, 2008

Air Conditioner Buying Tips

Most new homes today have air conditioning units. It is more unusual to see homes without central air then to see ones with it nowadays. Air conditioning can be a necessity in warmer climates for the comfort of the family. Most air conditioner units will range from three to six thousand dollars, including installation. This is not a minor investment but one necessary for comfort. If you need a new air conditioner, there are several things to consider prior to purchasing.

Air conditioning units should be installed by a contractor who is experienced with this type of work. Depending on existing ducts and the type of unit purchased, the price may vary greatly. Get several estimates from qualified contractors before deciding on the unit and installer. Ensure the contractor has experience and works well with you. Get references and check them thoroughly.

Air conditioner units use electricity to run. If the unit is used often this can increase energy costs significantly. This is especially true in warmer climates where it is a necessity to cool the home. To help combat these costs, it is advisable to look at the efficiency of the unit. This may mean a larger initial investment, but should save money in the long run.

The efficiency rating is required to be on all air conditioners. Compare units carefully to determine the cost for each type of efficiency. The more efficient a unit is, the more money you will save on energy bills. A more efficient air conditioner will take less energy to run and cool the entire house.

You will need to determine the appropriate size of the unit needed for your house. This is an important step because units that are too small will have to work harder to cool the home. Units that are too large are simply wasteful and unnecessary. A qualified air conditioner contractor will be able to analyze the size of your home and make recommendations on the size needed.

Always get a contract before starting work with any contractor. Make sure all the costs are clearly spelled out. This should include both the cost of the unit and installation. It should also detail payment policies and warranties. Warranties generally cover the compressor and additional parts. Do not choose a unit that has anything less than a five year warranty on the compressor, but a ten year warranty is better. Additional parts may be warranted anywhere from one to five years and are usually separate.

Gray Rollins is a featured writer for AirConditioningZone.com. To learn more about central air and air conditioner installation, visit us.

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Friday, January 18, 2008

Portable Air Conditioners - an Inexpensive Cooling Solution for Your Home

Portable air conditioners have become very popular in recent years. Many people use them even if they have a central system because portable A/C can provide excellent cooling for a significantly lower cost. Find out about the pros and cons of a mobile A/C unit and if one could work for you. A portable air conditioner is a self contained unit, usually about 30 inches tall and about 80 pounds in weight. The best thing is that it doesn't require any installation: it stands on the floor and you don't have to fit it in your window or your wall. Most mobile A/C units have little wheels, so you can easily move them around. Portable A/C pros: - you can move your portable unit from room to room, so there is no need to buy a window-mounted air conditioner for each room - you don't have to block your window or make holes in your wall - a portable air conditioner is ready to use as soon as you unpack it - using a mobile air conditioner to cool only one room instead of switching on a central system saves you a lot on energy bills Parable air conditioner cons: - a portable unit costs slightly more than a window air conditioner with a similar cooling capacity - comparable to central air conditioning and mini-split systems (where the compressor is outside), portable A/C is loud. If noise is an issue, look at the reviews of several portable units and select the one that makes the least noise. Is portable A/C effective in cooling large rooms? That depends on the size of your unit. Small portable units with cooling capacities of about 8000 BTU are perfect for a 300 sq. foot room, while larger 24000 BTU air conditioners can effectively cool a 1000 sq. foot room. So, as you can see, a properly sized mobile air conditioner can do a good job even in a very large room. However, you should know that larger doesn't necessarily mean better. An air conditioner that is too large will consume more energy and won't cool your room effectively, because it will stop and start constantly. Portable air conditioner energy efficiency Everybody knows that air conditioners chew a lot of energy, so energy efficiency is a big issue. However, recent developments in technology allow manufacturers to produce very efficient air conditioners. A few years ago an EER (energy efficiency ratio) of 6 or 7 was considered good. Now the standard is 12 or higher. Modern portable air conditioners are as energy efficient as window or mini split units. To select the most efficient air conditioner, look at its EER - the higher, the better. Also choose a unit with an Energy Star. The Energy Star means that an air conditioner meets energy efficiency guidelines set by the US Environmental Protection Agency and the Department of Energy. How affordable is a mobile air conditioner? You might be surprised to learn that portable A/C is not too expensive. The prices have gone down significantly, in recent years, and now you can buy a good unit from around $300. Of course, air conditioners with a larger cooling capacity cost more, and so do those with higher energy efficiency ratings. However, when it comes to paying more for a more efficient unit, you actually save money because your energy bill will be lower.

To conclude, if you don't have air conditioning and don't feel like investing in a central system, a portable air conditioner can be a great alternative. And if you have a central A/C, it's still a good idea to have a portable unit for cooling just the room you are in, instead of the entire house. It can significantly reduce your bills.

Tanya Turner publishes 100 Air Conditioner Reviews.com where you can find tips on air conditioner shopping, price comparison and reviews of portable air conditioners .

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Thursday, January 10, 2008

Air Conditioners - How to Cut Running Costs in Half

In today's world, most people have invested in one form of an air conditioner or another. We have either window air conditioners in our homes or central air conditioners. They keep us cool in the extreme summer heat without fail; however, have you ever set back and looked at the costs of running an air conditioner? When compared to the common household fan the amount of electricity required to run an air conditioner is phenomenal.

When using an air conditioner there are many different factors that can directly affect the cost of running it. These factors include the geographical location of your home, where you live and the amount of work the air conditioner has to do greatly influence the cost. If you live in an area that has mild summers and extremely cold winters, obviously your air conditioner will not have to work as hard. However, if you live in an area, that has warm winters and boiling summers the air conditioner will have to work double time to maintain comfort.

The difference in weather conditions from year to year will affect the costs as well. This is basically geared towards the difference in costs per year. One summer might be cooler than the next, which will lead to a greater bill.

The efficiency rating of your air conditioner plays an important role in the amount of electricity used. Most all appliances in today's world are rated, when you purchase an air conditioner it will have a tag telling you the amount of electricity that appliance uses. Look for air conditioners that use minimal electricity, which will save you money each year. If you have a model that is 10 years or older, it is definitely time to consider a new one.

Another important factor is the size of the air conditioner versus the house-cooling load. All air conditioners come in different sizes, and each will state the amount of space it is designed to cool. For example, an apartment could do with just one or two window air conditioners, while a three-bedroom house could not. Closely consider the amount of space you need to cool when considering an air conditioner. While larger air conditioners will cost more money, it will typically save you money in the long run on usage.

The setting on your thermostat greatly effects the cost. A higher setting will result in the air conditioner running less, while lowering the setting will cause it to run more often. One electric company suggests keeping the thermostat above 78 degrees. This can save you 10 to 20% on cooling costs.

Finally, the local cost of electricity influences the general cost of running your air conditioner. This is something you have no control over, however, you can control your own cost by saving energy.

Here is a general look at the difference of running an air conditioner vs. running a Ceiling or oscillating fan, at medium speed.

Running a central air conditioner that is three ton (and of average efficiency) for 8 hours per day for 15 days per month, with the average rate per kWh (kilowatt per hour) being 0.17, the average cost per month for the air conditioner alone will be $97.92. Amazing isn't it? This does not even include washer, dryer, lights, refrigerator, or stove, only the air conditioner.

On the other hand, running a ceiling fan or oscillating fan at medium speed, for 8 hours per day, for a full 30 days, at an average rate per kWh of 0.035 is only $1.43. With this comparison you could run 68 ? fans for a full month before you would reach the cost of the central air conditioning unit.

There are many other things you can do to lower you electric bill. Things such as, inspect, clean, or replace your air conditioner filters monthly. When you are not in your home, raise the temperature on your thermostat, keeping in mind pets when you do. Lower the temperature of your water heater to 120 degrees, wash only full loads in your dishwasher or clothes washer, and use the energy saving cycle on the dryer.

Other steps you can take include, replacing incandescent bulbs with fluorescent lamps, this could save up to 75% on lighting costs. You should also caulk all windows, doors, and pipes to prevent air leaks in or out, use weather stripping around windows, doors and pipes as well. Have your ducts tested for air leaks; leaking ducts can reduce the efficiency of your air conditioner by up to 20%.

Ethan K. Roberts writes on a variety of topics not limited to air conditioners. Also available are more articles on room air conditioners and air conditioner rental.

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Tuesday, January 8, 2008

Central Air Conditioners

When buying new central air conditioning equipment, it is very important to have the work done by a qualified contractor. Most review sites and available information say that the best way to save money on a central conditioning unit is by hiring a good contractor. This is followed in close second by picking an energy efficient system. A proper installation of a central air conditioner will ensure that the unit is tightly sealed and no energy is wasted thought leaky ducts thus saving as much money as possible.

When speaking of saving money through efficient air conditioning systems the topic of SEER usually comes up.Central air conditioners are rated by something called SEER or seasonal energy efficiency ratio. Without going into details, the higher the SEER the more efficient your central conditioning system is thus saving you money and helping the environment through less power demand.

Most central air cooling systems run on Freon and have for many years but this is apparently going to change. Freon will be replaced by a newer refrigerant called Puron that is friendlier to the environment no later than 2010. The good news about this is that although Puron powered central air conditioners may cost more initially, the Freon machines and parts are going to get scarce. Getting scarce parts for your conditioning unit will cost you as all the older machines start to break down and need repairs, but parts are harder to find.

Speaking of costs, this is the one glaring down point of a central cooling system. While cost may not be an issue for some, the central air conditioner unit is the most expensive way to cool your house on the initial investment. Because the conditioning unit must be installed and venting systems run, you will have to hire a contractor. Therefore part of the cost of getting a central cooling system will depend the flexible pricing of the local contractor. With the unit air conditioning systems this is not an issue, but again with the unit systems you can only cool one room at a time and they could be a bit of an eye sore in a posh setting.

Ray Burton explains about different kinds of air conditioners, how they work and what to look for when buying your first portable or window air conditioner unit

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Sunday, December 30, 2007

Portable Air Conditioners Ensure Economy And Convenience

Small is beautiful and convenient and so is the portable air conditioner as it can be shifted from one place to the other very easily. Read on to find out all the other advantages.

With the onset of the damp weather, it becomes difficult to survive without constant central air conditioning but that can prove to be quite expensive. The answer to this problem is a portable air conditioner as it has many advantages. It is easy to shift from one place in the home to another and that makes a portable air conditioner the ideal cooling system solution for your home, office or industrial site.

The portable air conditioners are easy and quick to install, as they do not involve any lifting or tearing up of windowsills. Moreover it can be shifted very easily from one place in the home to the other. For taking care of the hot spots in the central air conditioning, the portable air conditioners are far more convenient than window air conditioners. It is also ideal for window shapes, which present problems for installation. There is nothing like portable air conditioners for use as a spot cooler in the home.

A portable air conditioner is an excellent choice for saving money as just one unit needs to be purchased and it can be shifted easily to where you need it as it is mounted on castors and some can weigh only about 36 pounds. Moreover, as only one room is cooled at a time instead of the whole house, the total energy consumption is very low as compared to other air conditioning systems.

Another advantage of portable air conditioners is the energy efficiency that they provide. The average efficiency is in the 8 to 10 range although some are as high as 15, which is 50 percent better than most older central air conditioners. The small size of the portable air conditioners is very advantageous and as such it can fit in a corner or against a wall. It functions like an effective dehumidifier if you do not vent the warm exhaust air out through a window and its size is also the same as that of a room dehumidifier.

In order to reduce humidity and allergies, even the small ones remove 35 pints of moisture per day from the room air. The portable air conditioners also use the heat-exchange principle as the other air conditioners to cool and dehumidify the air. The operating principle is also similar to a window air conditioner as the room air circulates over cold evaporator coils to cool and dehumidify it inside the unit. The room air is exhausted outdoor after flowing over the hot condenser. There is no chance of already-cooled indoor air escaping outside as two ducts are now used.

Nowadays, you have electronic controls in most models and you can set the desired room temperature, blower speed, start and stop timer, and operation mode (cool, dehumidify, heat). The portable air conditioners also have hand-held remote control with which you can conveniently change all the settings as per your need.

The other features of portable air conditioners include a built-in air cleaner with an optional charcoal filter and oscillating louvers to distribute the cool air throughout the room. You can also switch off the louvers to direct the flow of air towards yourself, if you so desire.

Get the right air conditioner the first time. Discover the advantages of different air conditioner models and which one best suits your needs by reading our free articles at: http://www.nichearticles.com/airconditioner/

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Wednesday, December 26, 2007

Automotive Air Conditioner Basic Troubleshooting Tips

If your automotive air conditioner isnt working quite right, here are a few ideas to begin. First of all start with the control panel on your dashboard. Most automobiles have an A/C button that actually turns the compressor on and allows cold air to be circulated. You might have accidentally hit the recirculation button instead of the A/C button. (Dont laugh, I had a friend that spent a week in a hot car and all he needed to do was press the right button.) The second thing to check is the actual function of the controls. Do they move at all? Are they loose and giggle around? The big question is do they feel different from the last time your air conditioner worked? This could tell if the controls are messed up and need replacing. Your air conditioner system may be fine but the controls could be frozen or broken. If your controls seem to be functioning, lets move to the blower fan. Turn on your car and start youre air conditioner as you normally would. Then turn your blower to its highest setting. Can you here your fan blowing? If you can hear it, does it sound weak or whining. This could signal that your blower motor is malfunctioning or needs to be replaced. If it doesnt work at all, check the fuse for the blower motor. The fuse for your blower motor should be located in the fuse box under the dash. Most automobiles have the fuses clearly labeled. First take out the blower fan fuse with the removal tool provided in the fuse box. A blown fuse should be easy to identify. However if you are unsure, replace it with a similar rated fuse and try your blower again. If that fuse blows you may have a bad blower motor or a short in the circuit. In this case, you will need an authorized mechanic to fix it.

If the blower fan is working properly and you can only get cold air out of the defroster vents, you may have vacuum-system supply line problem. To check for this, look for a small black plastic tube going from the engine area through the dash. It is usually right by the refrigerant lines. Check this tube and see if it has holes or is not connected. If all of these little tips are not helping and youre A/C doesnt blow cold air no matter how many switches you turn on or off, you will probably need an certified mechanic. Good luck and stay cool!

Jason is the webmaster for Red Hill Supply - Online Air Tools Automotive Air Conditioning Tools, Refrigerant Leak Detectors, and More - Red Hill Supply

redhillsupply.com

jmiller@redhillsupply.com

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Wednesday, December 19, 2007

HVAC Air Filters Amongst The Best Air Filters For Air-Conditioning

Most of the time people are not aware about the dangers of air pollution inside our rooms. Our rooms are most polluted places in the cities we live. A number of small particles of dust, dirt, and pollen circulated within our living rooms and we continue breath such airs for long hours. The particles in air can increase our allergy symptoms or even can trigger some of the diseases. We only care about pollution in the cities and HVAC air filters help us in controlling air pollution especially inside our homes. HVAC air filters are widely used in various applications such as air conditioning, heating and other ventilating applications. These are designed in such a way so that the HVAC air filters provide us the best air.

Although we might use one or other equipment fitted with HVAC filter so that we inhale pure air, but we hardly realize the damage a room air can cause to our health. We live more than 50 percent time in our room, which is many times more polluted than the air outside the room, and we ignore it always. HVAC filters are highly efficient filter papers used in our ventilation systems and are able to absorb this smaller number of particles from our room air.

If we look of the indoor pollutants, we will find a number of hazardous pollutants that are dealt by us daily in our houses. These are sometimes man made pollutants and we should try to avoid them and if it is not possible to avoid them, what we can do is best we can use HVAC air filters in our ventilation systems so that the pollutant created by them do not remain prolong in the air.

A large number of companies are producing HVAC air filters and some of the company?s products are excellent in the performance. There are huge positive feedbacks have been received for polyester based HVAC air filters and now these are widely been used for various applications. These are not only useful for residential buildings but these HVAC air filters also suit best requirements of commercial buildings.

HVAC air filters are the best choice for today as many routes that probably we might not know are creating more and more indoor pollution. The air pollution level in some of our houses is continuously rising and smoking is one of the reasons for it. More and more people smoke and that too inside the living rooms and fine particles produced by smoke are deadly enough to create hundreds of times more pollution than the pollution created by a diesel vehicle on the road. We must understand the needs to control this harmful nature of indoor pollution and therefore we should use an HVAC air filter especially in our ventilators.

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Sunday, December 9, 2007

HVAC Maintenance

Does HVAC Maintenance Pay For Itself?

Most people would not even consider not changing the oil in their vehicle. Maintaining your HVAC system is no different. By getting involved in a quality maintenance program you will reduce energy costs, extend equipment life, optimize comfort conditions and increase system reliability. Just knowing your equipment is operating safely is a peace of mind in itself.

Many businesses use what I call ?the breakdown maintenance program.? In other words ?I?ll worry about it when it breaks.? We all know this almost always happens at a inconvenient time like when it?s 20 below zero or 95 degrees in the shade. This way of handling things is also very hard on your equipment and may decrease the life of it by as much a half. Maintaining is much cheaper than replacing.

Here are some of the savings you can expect from a quality maintenance program:

Adjusting operating sequence of equipment 25-35%

Cleaning Coils 5-15%

Changing dirty air filters 10-15%

Removing scale from condenser coils 25-30%

Adjusting air/fuel ratio of burner 15%

Cleaning burner assembly 15%

Removing soot from fire side of burner 9%

Eliminating V-belt slippage and pulley alignment 15-20%

Not to mention the money saved in break down service calls.

So if your not already set up with some type of HVAC maintenance program you may want to seriously consider talking to your local HVAC contractor about getting set up with a program to meet your needs.

Information provided by Terry Manlick of HVAC Maintenance & Supplies Other HVAC related articles as well as maintenance supplies can be found at http://www.mainsupplies.com

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