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Understanding Ac levels

Understanding Ac levels

Our Unxerstanding Policy governs the Understanding Ac levels of your information. Reading List The following lfvels Understanding Ac levels more information on air conditioning. Getting an air conditioner with too many BTUs for a home your size can raise your energy costs. Related Posts: What Is a R12 to Ra Conversion Chart? Understanding Ac levels


Welcome to AC Theory

Understanding Ac levels -

The typical waveform for an alternating current is a sine wave see Figure 1. There are several indicators that must be taken into account when working with an AC power supply:. Alternating current AC is the way electric power is transmitted from generating facilities to end users.

It is used for power transportation because electricity needs to be transformed several times during the transportation process. Electric generators produce voltages of about 40,V, or 40kV. This voltage is then stepped up to anywhere between kV and kV, to reduce power losses when transporting electric current over long distances.

Once it reaches its destination area, the voltage is stepped down to between 4kV and 35kV. Finally, before the current reaches individual users, it is reduced to V or V, depending on the location. All these changes in voltage would be either complicated or very inefficient to do with direct current DC , because linear transformers depend on voltage fluctuation to transfer and transform electrical energy, so they can only work with alternating current AC.

By using a transformer, the alternating current AC input voltage is reduced to a value more suitable for the intended application. Then, the reduced AC voltage is rectified and turned into a direct current DC voltage, which is filtered in order to further improve the waveform quality Figure 2.

Because the input voltage is transformed at the input, the necessary transformer would have to be very large and therefore very heavy. At low frequencies e. This demands large transformer cores, which makes miniaturization of these power supplies practically impossible.

These linear regulators dissipate any extra energy in the form of heat. For low power, does not pose much of a problem. However, for high power, the heat that a regulator would have to dissipate to maintain a constant output voltage is very high, and would require adding extremely large heatsinks.

Switching power supplies are now possible thanks to the evolution of semiconductor technology, especially thanks to the creation of high-power MOSFET transistors, which can switch on and off very quickly and efficiently, even if large voltages and currents are present.

In switching AC power supplies, the input voltage is no longer reduced; rather, it is rectified and filtered at the input. Then the DC voltage goes through a chopper, which converts the voltage into a high-frequency pulse train.

Finally, the wave goes through another rectifier and filter, which converts it back to direct current DC and eliminates any remaining alternating current AC component that may be present before reaching the output see Figure 3.

As could be expected, this new design method does have some drawbacks. This creates a need for more complex control circuitry, which in turn adds complexity to the design. Nevertheless, these filters are made up of components that can be easily integrated, so it does not affect the size of the power supply significantly.

An alternating current AC power supply can either be single-phase or three-phase:. The main difference between these two configurations is the ability to add a neutral wire see Figure 5. Delta connections offer greater reliability, but Y connections can supply two different voltages: phase voltage, which is the single-phase voltage supplied to homes, and line voltage, for powering larger loads.

Because a standard power distribution system must supply power to both three-phase and single-phase systems, most power distribution networks have three lines and a neutral. This way, both homes and industrial machinery can be supplied with the same transmission line.

Therefore, the Y configuration is the most commonly used for power distribution, whereas the delta configuration is typically used to power three-phase loads, such as large electric motors. The voltage at which the power grid delivers single-phase electric power to its users has various values, depending on the geographical location.

Otherwise, you could damage the power supply or the device connected to it. Table 2 compares the grid voltages in different areas around the world. In the western city of Osaka, electricity suppliers bought 60Hz generators from the United States, while in Tokyo, which is in the east of Japan, they bought 50Hz German generators.

Both sides refused to change their frequency, and to this day Japan still has two frequencies: 50Hz in the east, 60Hz in the west. As mentioned before, three-phase power is not only used for transportation, but is also used to power large loads, such as electric motors or charging large batteries.

This is because the parallel application of power in three-phase systems can transfer much more energy to a load, and can do so more evenly, due to the overlapping of the three phases see Figure 6.

Figure 6: Power Transmission in Single-Phase Left and Three-Phase Right Systems. For example, when charging an electric vehicle EV , the amount of power you can transfer to the battery determines how fast it charges.

These chargers, are limited in power by the grid and the AC socket. On the other hand, three-phase power supplies convert the power from AC to DC externally, and can transfer over kW to the battery, enabling super-fast charging.

Alternating current is used to transport electric power all across the electric grid, from generators to end users. An alternating current AC circuit can be configured as a single-phase or a three-phase system.

Single-phase systems are simpler, and can deliver enough power to supply an entire house, but three-phase systems can deliver much more power in a more stable way, which is why they are frequently used to supply power for industrial applications.

By contrast, switching power supplies have become extremely popular, because they use switching regulators to convert AC to DC power. Did you find this interesting? Get valuable resources straight to your inbox - sent out once per month!

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Log in. Don't have an account? Are you considering buying a new air conditioner? Or, are you dissatisfied with the operation of your current air conditioner?

Are you unsure whether to fix or replace it? Are you concerned about high summer utility bills? If you answered yes to any of these questions, this publication can help.

With it, you can learn about various types of air conditioning systems and how to maintain your air conditioner, hire professional air conditioning services, select a new air conditioner, and ensure that your new air conditioner is properly installed. Proper sizing, selection, installation, maintenance, and correct use are keys to cost-effective operation and lower overall costs.

A Technical Explanation of How a System Works Click here for a "Not-So-Technical" Explanation of How It Works Air conditioners employ the same operating principles and basic components as your home refrigerator. An air conditioner cools your home with a cold indoor coil called the evaporator. The condenser, a hot outdoor coil, releases the collected heat outside.

The evaporator and condenser coils are serpentine tubing surrounded by aluminum fins. This tubing is usually made of copper. A pump, called the compressor, moves a heat transfer fluid or refrigerant between the evaporator and the condenser.

The pump forces the refrigerant through the circuit of tubing and fins in the coils. The liquid refrigerant evaporates in the indoor evaporator coil, pulling heat out of indoor air and thereby cooling the home.

The hot refrigerant gas is pumped outdoors into the condenser where it reverts back to a liquid giving up its heat to the air-flowing over the condenser's metal tubing and fins. BACK TO TOP. Types of Air Conditioners. The basic types of air conditioners are room air conditioners, split-system central air conditioners, and packaged central air conditioners.

Room air conditioners cool rooms rather than the entire home. If they provide cooling only where they're needed, room air conditioners are less expensive to operate than central units, even though their efficiency is generally lower than that of central air conditioners.

Smaller room air conditioners i. Larger room air conditioners i. The largest models require a dedicated volt circuit. Central air conditioners circulate cool air through a system of supply and return ducts. Supply ducts and registers i. This cooled air becomes warmer as it circulates through the home; then it flows back to the central air conditioner through return ducts and registers.

A central air conditioner is either a split-system unit or a packaged unit. In a split-system central air conditioner , an outdoor metal cabinet contains the condenser and compressor, and an indoor cabinet contains the evaporator.

In many split-system air conditioners, this indoor cabinet also contains a furnace or the indoor part of a heat pump. The air conditioner's evaporator coil is installed in the cabinet or main supply duct of this furnace or heat pump.

If your home already has a furnace but no air conditioner, a split-system is the most economical central air conditioner to install. In a packaged central air conditioner , the evaporator, condenser, and compressor are all located in one cabinet, which usually is placed on a roof or on a concrete slab next to the house's foundation.

This type of air conditioner also is used in small commercial buildings. Air supply and return ducts come from indoors through the home's exterior wall or roof to connect with the packaged air conditioner, which is usually located outdoors. Packaged air conditioners often include electric heating coils or a natural gas furnace.

This combination of air conditioner and central heater eliminates the need for a separate furnace indoors. An evaporative cooler also called a "swamp cooler" is a completely different type of air conditioner that works well in hot, dry climates. These units cool outdoor air by evaporation and blow it inside the building, causing a cooling effect much like the process when evaporating perspiration cools your body on a hot but not overly humid day.

When operating an evaporative cooler, windows are opened part way to allow warm indoor air to escape as it is replaced by cooled air.

Evaporative coolers cost about one-half as much to install as central air conditioners and use about one-quarter as much energy. However, they require more frequent maintenance than refrigerated air conditioners and they're suitable only for areas with low humidity. Older air conditioners may still be able to offer years of relatively efficient use.

However, making your older air conditioner last requires you to perform proper operation and maintenance. Yearly Maintenance needs to be performed by a licensed professional. Click Here to see our Air Conditioning Maintenance Agreement. One of the most common air conditioning problems is improper operation.

If your air conditioner is on, be sure to close your home's windows and outside doors. Other common problems with existing air conditioners result from faulty installation, poor service procedures, and inadequate maintenance.

Improper installation of your air conditioner can result in leaky ducts and low airflow. Many times, the refrigerant charge the amount of refrigerant in the system does not match the manufacturer's specifications.

If proper refrigerant charging is not performed during installation, the performance and efficiency of the unit is impaired. Service technicians often fail to find refrigerant charging problems or even worsen existing problems by adding refrigerant to a system that is already full.

Air conditioner manufacturers generally make rugged, high quality products. If your air conditioner fails, it is usually for one of the common reasons listed below:. If your air conditioner is low on refrigerant, either it was undercharged at installation, or it leaks.

If it leaks, simply adding refrigerant is not a solution. A trained technician should fix any leak, test the repair, and then charge the system with the correct amount of refrigerant.

Remember that the performance and efficiency of your air conditioner is greatest when the refrigerant charge exactly matches the manufacturer's specification, and is neither undercharged nor overcharged.

If you allow filters and air conditioning coils to become dirty, the air conditioner will not work properly, and the compressor or fans are likely to fail prematurely.

The compressor and fan controls can wear out, especially when the air conditioner turns on and off frequently, as is common when a system is oversized. Because corrosion of wire and terminals is also a problem in many systems, electrical connections and contacts should be checked during a professional service call.

An air conditioner's filters, coils, and fins require regular maintenance for the unit to function effectively and efficiently throughout its years of service. Neglecting necessary maintenance ensures a steady decline in air conditioning performance while energy use steadily increases.

The most important maintenance task that will ensure the efficiency of your air conditioner is to routinely replace or clean its filters. Clogged, dirty filters block normal airflow and reduce a system's efficiency significantly.

With normal airflow obstructed, air that bypasses the filter may carry dirt directly into the evaporator coil and impair the coil's heat-absorbing capacity. Filters are located somewhere along the return duct's length.

Common filter locations are in walls, ceilings, furnaces, or in the air conditioner itself. Some types of filters are reusable; others must be replaced.

They are available in a variety of types and efficiencies. Clean or replace your air conditioning system's filter or filters every month or two during the cooling season. Filters may need more frequent attention if the air conditioner is in constant use, is subjected to dusty conditions, or you have fur-bearing pets in the house.

The air conditioner's evaporator coil and condenser coil collect dirt over their months and years of service.

A clean filter prevents the evaporator coil from soiling quickly. In time, however, the evaporator coil will still collect dirt. This dirt reduces air-flow and insulates the coil which reduces its ability to absorb heat.

Therefore, your evaporator coil should be checked every year and cleaned as necessary. Outdoor condenser coils can also become very dirty if the outdoor environment is dusty or if there is foliage nearby. You can easily see the condenser coil and notice if dirt is collecting on its fins.

You should minimize dirt and debris near the condenser unit. Your dryer vents, falling leaves, and lawn mower are all potential sources of dirt and debris. Cleaning the area around the coil, removing any debris, and trimming foliage back at least 2 feet allow for adequate airflow around the condenser.

The aluminum fins on evaporator and condenser coils are easily bent and can block air-flow through the coil. Air conditioning wholesalers sell a tool called a "fin comb" that will comb these fins back into nearly original condition.

An enormous waste of energy occurs when cooled air escapes from supply ducts or when hot attic air leaks into return ducts. For central air conditioning to be efficient, ducts must be airtight. Hiring a competent professional service technician to detect and correct duct leaks is a good investment, since leaky ducts may be difficult to find without experience and test equipment.

Ducts must be sealed with duct "mastic. Obstructions can impair the efficiency of a duct system almost as much as leaks. You should be careful not to obstruct the flow of air from supply or return registers with furniture, drapes, or tightly fitted interior doors.

Dirty filters and clogged evaporator coils can also be major obstructions to airflow. The large temperature difference between attics and ducts makes heat conduction through ducts almost as big a problem as air leakage and obstructions.

Ducts in attics should be insulated heavily in addition to being made airtight. Air conditioners are rated by the number of British Thermal Units Btu of heat they can remove per hour.

Another common rating term for air conditioning size is the "ton," which is 12, Btu per hour. The size of an air conditioner depends on:. An air conditioner's efficiency, performance, durability, and initial cost depend on matching its size to the above factors. Make sure you buy the correct size of air conditioner.

Two groups—the Air Conditioning Contractors of America ACCA and the American Society of Heating, Refrigerating, and Air Conditioning Engineers ASHRAE —publish calculation procedures for sizing central air conditioners.

Reputable air conditioning contractors will use one of these procedures, often performed with the aid of a computer, to size your new central air conditioner. Be aware that a large air conditioner will not provide the best cooling.

Buying an oversized air conditioner penalizes you in the following ways. It costs more to buy a larger air conditioner than you need. The larger-than-necessary air conditioner cycles on and off more frequently, reducing its efficiency.

Frequent cycling makes indoor temperatures fluctuate more and results in a less comfortable environment. Frequent cycling also inhibits moisture removal. In humid climates, removing moisture is essential for acceptable comfort. In addition, this cycling wears out the compressor and electrical parts more rapidly.

A larger air conditioner uses more electricity and creates added demands on electrical generation and delivery systems. Each air conditioner has an energy-efficiency rating that lists how many Btu per hour are removed for each watt of power it draws. For room air conditioners, this efficiency rating is the Energy Efficiency Ratio, or EER.

For central air conditioners, it is the Seasonal Energy Efficiency Ratio, or SEER. These ratings are posted on an Energy Guide Label, which must be conspicuously attached to all new air conditioners. Many air conditioner manufacturers are participants in the voluntary EnergyStar® labeling program see Source List in this publication.

EnergyStar®-labeled appliances mean that they have high EER and SEER ratings. In general, new air conditioners with higher EERs or SEERs sport higher price tags. However, the higher initial cost of an energy-efficient model will be repaid to you several times during its life span. Your utility company may encourage the purchase of a more efficient air conditioner by rebating some or all of the price difference.

Click here to view energy "Benefits of the CFC Phase-out". Room air conditioners generally range from 5, Btu per hour to 14, Btu per hour. National appliance standards require room air conditioners built after January 1, , to have an EER of 8.

Select a room air conditioner with an EER of at least 9.

Understanding Ac levels Quality. Learning HVAC. Your Understanding Ac levels. And that means what, Understandnig BTU is short for British Thermal Unit, a unit of measurement that shows just how much energy your air conditioner uses to remove heat from your home within an hour. The HVAC Heating, Ventilation, and Air Conditioning system Understanding Ac levels your levelz Visceral fat and inflammation levela crucial role in providing comfort during your journeys. Metabolic health community important aspect of the HVAC levfls is the Understanding Ac levels charge, which ensures optimal cooling performance. In this article, we'll explore the basics of a vehicle's HVAC system, its components, and provide insights into the AC charging process. The HVAC system in a vehicle is responsible for regulating the temperature, airflow, and humidity inside the cabin. It consists of several key components:. AC charge refers to the level of refrigerant commonly known as Freon present in the HVAC system.

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