Air Conditioner Thermostats

A thermostat is an apparatus for maintaining the temperature of a system within a particular range by directly or indirectly controlling the flow of heat energy into or out of the system. All air conditioners have thermostats that can be manually operated or automatically preprogrammed to work at regulating the room temperature. There are many ways in which you can use an air conditioner thermostat effectively.

One of the most successful yet economical ways to reduce your air conditioning costs is to adjust the thermostat setting on the air conditioner. The savings are more noteworthy when you set your thermostat at 78 degrees Fahrenheit or higher. For each degree you raise the thermostat setting, you reduce seasonal cooling costs by 7 percent to 10 percent. In doing so, you can use ceiling fans in addition to the air conditioner and thus, save a lot of money.

Most centrally located air conditioner thermostats are equipped with two fan settings, 'on' and 'auto'. When the thermostat setting is set to 'on' the fan runs constantly and when it is set to 'auto' the fan runs only during cooling cycles when the air conditioner compressor is in use. When the air conditioner is in use all day, the cooling compressor only operates about 50 percent of the time, that is, for about 12 hours. The extra fan operating time that occurs when the thermostat is set to 'on' can add roughly $25 to monthly air conditioning bills. Using the 'auto' setting, alternatively, saves energy and money because the fan operates fewer hours. Besides achieving energy and cost savings, the 'auto' setting also promotes more comfort by offering better humidity control as moisture removed during the cooling cycle is re-circulated back into the home while the compressor is off.

Thus, thermostats play an important role in the cost and function of an AC.

Air Conditioner Rentals provides detailed information on air conditioner rentals, portable air conditioner rentals, window air conditionar rentals, RV air conditioner rentals and more. Air Conditioner Rentals is affiliated with Window Air Conditioners.

Air Conditioner Rental Advice

Air conditioners (AC) are essential in many countries. However, temporary or short-term businesses, business meetings, wedding receptions, and high school or college functions are events that might require renting air conditioners. There are a lot of rental companies that lease air conditioners for a short or long period of time and charge a monthly rental fee.

There are numerous companies that offer air conditioners to rent at discounted prices, especially during the hot summer months. It is advisable to order an air conditioner well in advance, as the demand rockets during summer. When someone contacts a rental company for cooling necessities, the rental company usually sends one of their experts to examine the room. They will then recommend the right kind of air conditioner that will cool the room. The rental company provides this service for free. The company will quote a rental fee that is usually negotiable. An official contract is signed and the air conditioner is installed

Air conditioner rental companies deal in a variety of units, such as window, split, central, portable, industrial and many more. Usually, the type of AC is determined based on the venue that needs cooling. Prices differ in accordance with the type of AC installed. Central AC costs the most, while windows units are the least expensive. Some companies charge a deposit before installation. Any damage during usage is recompensed from the deposit money. If there are no deductions, the total deposit is reimbursed on return of the unit. The rental fee depends on the length of time the AC is required and its brand. Prices usually start in the low hundreds per month.

Air Conditioner Rentals provides detailed information on air conditioner rentals, portable air conditioner rentals, window air conditionar rentals, RV air conditioner rentals and more. Air Conditioner Rentals is affiliated with Window Air Conditioners.

Sizing - Part I - Air Conditioner Sizing

Summary

Air conditioner sizing means finding the air conditioner that can balance the heat gains and losses within a building. There is a famous way of sizing an AC. It is the square feet method. However, there the-also-famous Manual J method available, to size ACs accurately.

We hear a lot about air conditioner sizing, whenever we make the important choice of purchasing, or installing one. What does the word sizing really mean?

Air conditioners are designed for heat removal, or addition (if heat pump is included in the single package). Therefore, the "size" of an AC, will be specified in terms of heat removal, or addition capability.

Units that we use for air conditioner sizing, are BTU/hr (British Thermal Units per hour), Ton, and Watts. Some countries utilise one unit, more than the others, in air conditioner sizing.

It is excellent if you can remember the relationship between BTU/hr, Ton, and Watts. You can quickly gauge the AC size, in case if your friends use units - that are unfamiliar to you;

• 1 ton is equivalent to 12,000 BTU/hr. And,

• 12,000 BTU/hr is equivalent to 3,516 Watts - or 3.516 kW (kilo-Watts).

Concept and fundamental of air conditioner sizing

It is based on heat gain, and/or losses in a building. It is obvious that you will need to remove the amount of heat gain into your house - if it is hot outside. Similarly, you'll need to add in the heat loss from your house - if outside temperature is cold.

In short, heat gain and loss, must be equally balanced by heat removal, and addition, to get the desired room comfort that we want.

What determines the amount of heat removal and/or addition that we want?

It is determined by,

• the temperature difference between outside temperature, and our desired temperature. It is common sense that if you want a cool room, in a very hot climate, you'll need to remove a lot of heat. On the other hand, it does not take much to maintain a cool room, on a mild day

• the construction material, and arrangement of your building. Let's say, that you have two identical houses. One is build out of glass, and the other out of brick, and well insulated.

  Of course the one built with glass would require much more heat addition, or removal, compared to the other - given a same day.

  Two identical house, with different orientation with respect to the direction of sun rise and fall, will also influence the air conditioner sizing

• the surface area of the walls. The larger the surface area - the more heat that can loose, or gain through it. Hence, effects the AC size that you would need

• infiltration plays a part in determining our air conditioner sizing. Door gaps, cracked windows, chimneys - are the "doorways" for air to enter from outside, into your living space. Only you know how frustrating it can get, to feel a draft of chill, or hot air from outside

• activities and other equipment within a building. Cooking? Hot bath? Is it a gymnasium with a lot of intense exercise?

• the occupants. It takes a lot to cool a town hall full of people, doesn't it? Oh yes, we generate heat.

Square feet method?

You might have heard about the square feet method in air conditioner sizing. In fact, it is used often by many contractors, that we sometimes use it arbitrarily. This method have been generalised, and simplified by contractors, from sizing many ACs.

The most common relationship is, "1 ton for every 500 square feet of floor area". This method might work for a contractor, working in a small area, with similar type of houses or buildings, and similar wall material.

But, the relationship will not work, if you change the wall construction type, or if you move into a different area, with different climate. Simply said, this method of air conditioner sizing will only work for a confined group of building, in a given area.

However, this is method is reasonably useful for installing window, small split, or portable air conditioners.

Manual J

Now, this is the way we should do air conditioner sizing. Manual J is a database, with methodologies, formulas and guide for sizing and AC. This manual has been developed by ACCA (Air Conditioning Contractors of America) - with regular reviews.

It will provide you with necessary data for heat gain and heat loss calculations. Wall construction, building orientation, infiltration, shading, number of occupants, the temperature you would like to set, outside temperatures, are among the most important values it will look for, for proper air conditioner sizing.

This is indeed, an extensive manual, which is used by certified and experienced air conditioning contractors.

Manual J is just a tool. The important things are, the values that are put in it. If we put in accurate values, then our results will be come accurate. Otherwise, it's not going to help much.

What are amongst the important information, you should have for air conditioner sizing using Manual J? These are,

• required temperature range within your space,

• approximate temperature distribution within your area, to find out the number of months you have winter, summer, and mild weathers,

• wall surface area and material. Window surface area,

• any tinted window? Any insulated space?

• how many person is going to live within each space?

• what are the activities carried out throughout any day? How much cooking? How much of hot water utilisation?

• orientation of your building, with respect to the sun's rise and fall direction, and,

• sources of infiltration

Part II or air conditioner sizing is coming soon...
Provides information on air conditioners and air conditioning in her site,
http://www.air-conditioner-selection.com/

over here

Understanding Your Air Conditioner

So many people have them in their homes, but few people truly understand the basics behind their air conditioning units. They know enough to switch them on and set the temperature at the level they desire, but really know little about the parts that make the unit cool their house down. An air conditioner regulates the heat and cold in your house by controlling the humidity and temperature in each room, but do you know how it does this? Whether you are shopping for a new air conditioner or interested in learning about the one you have, the best place to start is with the general terms used to explain the functions of your unit.

BTU: A BTU or British Thermal Unit is the world wide measurement for energy. In layman?s terms it is the amount of heat that is needed to raise a pound of water by one degree of temperature. When you hear someone talk about BTUs in regards to air conditioning they are talking about the amount of heat a unit can remove from a standard sized room. The higher the BTU rating the bigger, more expensive, and heavier the air conditioner is. While many people think that bigger is better, when it comes to air conditioning that is not always the case. It is more important to correctly match the size of a room with the required amount of BTUs. Having too many or too few for the room?s size decreases efficiency and actually hinders the unit from doing its job.

Chassis: The chassis is simply the guts of your air conditioner. It is the frame and working parts exclude from the body of your unit. Smaller units often have a fixed chassis which is easiest to remove for winterizing. Larger units often have a slide out chassis that makes repair work a snap.

EER: The EER is simply calculated by dividing the BTUs into the number of watts. Air conditioners with higher EER numbers should be the most efficient. While a unit with a higher EER number will save you money in the long run, it will cost more to buy. If you don?t live in a really hot area, it might not be worth it to invest in a unit with an EER over 10.

Fan: The fan in an air conditioner works like every other fan you have ever seen. Its sole job is to move the air. When it comes to air conditioners an adjustable thermostat combined with an adjustable speed fan makes the unit very efficient. In an air conditioning unit, you want to look for louvers that not only adjust up and down, but right and left as well.

Filter: Air is surprisingly dirty and a good filter will make a big difference in the quality of the air you breathe. Clean air is also a must if you want to get the most efficient work from your air conditioner. Because clean air is so important to the operation and maintenance of your unit, it is important to change or clean your filters regularly. Because you will be dealing with the filter on a regular basis, it is a good idea to own an air conditioner that has an easily accessible filter.

Thermostat: A thermostat is simply a device used to regulate temperature. Thermostats are heat sensing and therefore able to adjust the output of your air conditioner based on the level of heat in a room. You can get thermostats that are manual or programmable, depending on your needs. If you can get an adjustable thermostat and a variable speed fan, your air conditioning unit will be very efficient.

Once you have a small understanding of how an air conditioning unit not only works, but works most efficiently and effectively, it is a lot easier to find a unit that fits your unique household needs and understand the most efficient ways to run it.

James brown writes about Home Tips and House Appliances

A Cars HVAC System

Not only do we depend on our cars to get us where we want to go, we also depend on them to get us there without discomfort. We expect the heater to keep us warm when it's cold outside, and the air conditioning system to keep us cool when it's hot.
We get heat from the heater core, sort of a secondary radiator, which is part of the car's cooling system. We get air conditioning from the car's elaborate air conditioning system.
Despite its relatively small size, the cooling system has to deal with an enormous amount of heat to protect the engine from friction and the heat of combustion. The cooling system has to remove about 6,000 BTU of heat per minute. This is a lot more heat than we need to heat a large home in cold weather. It's good to know that some of this heat can be put to the useful purpose of keeping us warm.
Air conditioning makes driving much more comfortable in hot weather. Your car's air conditioner cleans and dehumidifies (removes excess moisture), the outside air entering your car. It also has the task of keeping the air at the temperature you select. These are all big jobs. How do our cars keep our "riding environment" the way we like it?
Most people think the air conditioning system's job is to add "cold" air to the interior of the car. Actually, there is no such thing as "cold," just an absence of heat, or less heat than our bodies are comfortable with. The job of the air conditioning system is really to remove the heat that makes us uncomfortable, and returns the air to the car's interior in a "un-heated" condition. Air conditioning, or cooling, is really a process of removing heat from an object (like air).
A compressor circulates a liquid refrigerant called Refrigerant-12 (we tend to call it "Freon," a trade name, the way we call copy machines "Xerox" machines). The compressor moves the Refrigerant-12 from an evaporator, through a condenser and expansion valve, right back to the evaporator. The evaporator is right in front of a fan that pulls the hot, humid air out of the car's interior. The refrigerant makes the hot air's moisture condense into drops of water, removing the heat from the air. Once the water is removed, the "cool" air is sent back into the car's interior. Aaaaaah! Much better. Newer cars have R-134 as the refrigerant, but work in the same way as R-12.
Sometimes we worry when we catch our car making a water puddle on the ground, but are relieved to discover that it's only water dripping from the air conditioning system's condenser (no color, no smell, and it dries!).
Note: Refrigerant is extremely dangerous. Many special precautions must be taken when it is present. It can freeze whatever it contacts (including your eyes), it is heavier than air and can suffocate you, and it produces a poisonous gas when it comes in contact with an open flame.
The above information is directly from the Auto Insight program, which you can buy online from AutoEducation.com.
Common Problems:

From time to time the A/C system needs to be recharged to bring it back up to maximum efficiency. Sometimes a leak may cause loss of refrigerant and will need to be fixed before refilling. It's difficult to tell if a leak is present without specific test equipment so let it up to a professional.
Corrosion will cause the heater core (secondary radiator) to leak. This will manifest itself by leaving steam into the passenger compartment and fogging your windows. You will know there is a leak by the sweet smell coming from your vents. Unfortunately changing the heater core is usually not the easier job in the world, as engineers tend to squeeze them into some pretty tight spaces under the dash.
We get heat from the heater core, sort of a secondary radiator, which is part of the car's cooling system. We get air conditioning from the car's elaborate air conditioning system.
Despite its relatively small size, the cooling system has to deal with an enormous amount of heat to protect the engine from friction and the heat of combustion. The cooling system has to remove about 6,000 BTU of heat per minute. This is a lot more heat than we need to heat a large home in cold weather. It's good to know that some of this heat can be put to the useful purpose of keeping us warm.
Air conditioning makes driving much more comfortable in hot weather. Your car's air conditioner cleans and dehumidifies (removes excess moisture), the outside air entering your car. It also has the task of keeping the air at the temperature you select. These are all big jobs. How do our cars keep our "riding environment" the way we like it?
Most people think the air conditioning system's job is to add "cold" air to the interior of the car. Actually, there is no such thing as "cold," just an absence of heat, or less heat than our bodies are comfortable with. The job of the air conditioning system is really to remove the heat that makes us uncomfortable, and returns the air to the car's interior in a "un-heated" condition. Air conditioning, or cooling, is really a process of removing heat from an object (like air).
A compressor circulates a liquid refrigerant called Refrigerant-12 (we tend to call it "Freon," a trade name, the way we call copy machines "Xerox" machines). The compressor moves the Refrigerant-12 from an evaporator, through a condenser and expansion valve, right back to the evaporator. The evaporator is right in front of a fan that pulls the hot, humid air out of the car's interior. The refrigerant makes the hot air's moisture condense into drops of water, removing the heat from the air. Once the water is removed, the "cool" air is sent back into the car's interior. Aaaaaah! Much better. Newer cars have R-134 as the refrigerant, but work in the same way as R-12.
Sometimes we worry when we catch our car making a water puddle on the ground, but are relieved to discover that it's only water dripping from the air conditioning system's condenser (no color, no smell, and it dries!).
Note: Refrigerant is extremely dangerous. Many special precautions must be taken when it is present. It can freeze whatever it contacts (including your eyes), it is heavier than air and can suffocate you, and it produces a poisonous gas when it comes in contact with an open flame.
The above information is directly from the Auto Insight program, which you can buy online from AutoEducation.com.
Common Problems:

From time to time the A/C system needs to be recharged to bring it back up to maximum efficiency. Sometimes a leak may cause loss of refrigerant and will need to be fixed before refilling. It's difficult to tell if a leak is present without specific test equipment so let it up to a professional.
Corrosion will cause the heater core (secondary radiator) to leak. This will manifest itself by leaving steam into the passenger compartment and fogging your windows. You will know there is a leak by the sweet smell coming from your vents. Unfortunately changing the heater core is usually not the easier job in the world, as engineers tend to squeeze them into some pretty tight spaces under the dash.

Kevin Schappell maintains http://www.carbuyersclub.com where he gives advice on buying, selling, insurance, and financing. A mechanical engineer and car guy, Kevin has decided to spend his online time helping others learn about automobiles. To learn more about how your car works, Kevin has createdhttp://www.mycarwizard.com