Air Conditioner Components | HVAC Cooling 5/5 (1)

Air Conditioner Components

Air Conditioner Components | HVAC CoolingThere are big differences between heat pumps and air conditioners. While the air conditioner provides cooling the heat pump will provide heating and cooling so the components inside the air conditioner differ from the components inside the heat pump system. I constantly get emails from people asking if they can convert their air conditioner to a heat pump and of course they can but it is not recommended. I have even devoted an article to it for those who are considering converting their air conditioner to a heat pump.  After all, if you sit a heat pump next to a condenser it would be impossible to tell the difference from the air conditioner condenser to the heat pump condenser unless you looked inside the unit and was able to identify the different components from a heat pump to an air conditioner.  Here are the basic components of an air conditioner that make the air conditioner cool your home or business.

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What is a Metering Device – Refrigeration Components 5/5 (1)

What is a Metering Device – Refrigeration Components

What you will learn from What is a Metering Device:
1) We will answer the question, “What is a metering device” by defining the various types of HVAC equipment that use different types of metering devices and why.
2) How the metering device is involved in the refrigeration cycle
3) A comprehensive list of metering devices defining the metering devices commonly used in HVAC
4) Lots of resource and related links to help you learn more about metering devices.

What is a Metering Device - TXV- Thermostatic Expansion Valve
TXV Metering Device for a Heat Pump

Depending on the type of HVAC air conditioning or heat pump system it is and the efficiency range of the system will depend on the type of metering device the system has installed by the HVAC manufacturer of the air conditioner or heat pump system. Lower efficiency HVAC air conditioner and heat pump models have fixed orifice types while higher efficiency systems have thermostatic expansion valves installed in the HVAC air conditioner or heat pump system. The thermostatic expansion valve is far more complex than the fixed orifice metering device as the thermostatic expansion valve metering device modulates the refrigerant flow based on the temperature of the refrigerant temperature in the evaporator coil. This allows a specific amount of refrigerant, based on demand, to be metered into the evaporator coil while the fixed orifice metering device allows the same amount of refrigerant to enter the enter the coil no matter the conditions or the demand. As the liquid refrigerant enters the metering device it changes temperature and pressure. A partial amount of the liquid refrigerant flashes into a refrigerant gas or vapor as it leaves the metering device and enters the evaporator coil.

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Evaporator Coil for Heat Pumps & Air Conditioners | HVAC Refrigeration 5/5 (1)

Evaporator Coil for Heat Pumps & Air Conditioners

Old Evaporator Coil in a Rooftop Air ConditionerEvaporator Coil for Heat Pumps & Air Conditioners – the evaporator is responsible for absorbing heat into the coils and the refrigerant. The evaporator is an essential component of vapor compression refrigeration. This is usually done as result of passing air or water over the evaporator coil where a heat exchange process takes place. Heat leaves the air or water (whatever medium is used) and is absorbed into the coil and the liquid refrigerant. As more and more heat is absorbed by the evaporator coil and the refrigerant again changes state from a liquid to a refrigerant vapor. By the time the refrigerant leaves the evaporator coil the refrigerant should be all vapor and ready to be received again by the refrigeration compressor.

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The Condenser for Air Conditioners and Heat Pumps| HVAC Refrigeration 5/5 (1)

The Condenser for Air Conditioners and Heat Pumps - Trane Heat Pump Condenser
Trane Heat Pump Condenser

The Condenser for Air Conditioners and Heat Pumps

The condenser coil receives the high pressure high temperature refrigerant vapor from the compressor and immediately begins to remove heat from the refrigerant vapor. As the refrigerant vapor makes its way through the condenser coil more and more heat is removed and the refrigerant vapor changes state from a refrigerant vapor to a refrigerant liquid. While the liquid refrigerant changes temperatures from a higher temperature to a slightly lower temperature the pressure remains constant. As the refrigerant vapor leaves the condenser coil it makes it way to the metering device.

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The Compressor | HVAC Refrigeration No ratings yet.

The Compressor | HVAC Refrigeration

The Compressor in an HVAC refrigeration system
Compressor in an HVAC refrigeration system

In a typical HVAC air conditioner or heat pump there are four major components that make the process of refrigeration work. Basically, this is how air conditioners work. And how heat pumps work. The first component in the process is a compressor or the heart of any air conditioner or heat pump system.

The Compressor | HVAC Refrigeration – How it Works

HVAC Refrigeration Compressor – A compressor receives the refrigerant vapor from the evaporator coil and compresses the refrigerant vapor. The vapor enters the refrigeration compressor at a low pressure and a low temperature and leaves the refrigeration compressor at a higher temperature and a higher pressure. The lower temperature refrigerant vapor is responsible for providing cooling for the refrigeration compressor and it also carries with it a small amount of oil which migrates from the compressor throughout the system. After the refrigerant vapor is compressed it is discharged to the condenser coil. A compressor is an essential component in the vapor compression process of refrigeration.

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Fixing a Refrigerant Leak | Air Conditioner & Heat Pump Diagnosis & Repair 5/5 (1)

Fixing a Refrigerant Leak

Fixing a Refrigerant Leak – The Basics

Fixing a refrigerant leak on an evaporator coil
A new evaporator coil

Fixing a Refrigerant Leak – You had the new air conditioner or heat pump system installed some years ago and suddenly it stopped heating or cooling properly so you call the HVAC contractor to check it out. The HVAC technician arrives and spends about thirty minutes HVAC troubleshooting and then he comes to you with the news. The unit needs a charge of refrigerant. It is low on refrigerant (R-22) or R-410A. You ask the HVAC technician if it is normal for this to occur and he informs that, no, it is not normal for the HVAC system to lose refrigerant that you have a refrigerant leak.

So you advance to the next question and ask, “can you find and fix the refrigerant leak”. The HVAC technician says yes he can. Here are the options for you and depending on which option you choose will depend on the cost.

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Duct Work and High Ceilings | HVAC Duct Work Systems No ratings yet.

Duct Work and High Ceilings

Duct Work and High Ceilings | HVAC Duct Work Systems

Duct Work and High Ceilings – I did not see any reference to my question and would appreciate a response as soon as possible, as due to medical situation, have to make a decision soon. We own an OLD house with 13′ ceilings in a large part of the home and 11″ ceilings in the LV/DR and BR. We are oscillating on where to place the ducts….Floor or ceiling. It appears to be counterproductive to me to put the duct work in the ceiling since it will have so far to go. We are looking for the most cost effective, not upfront cost but operating cost, solution. In addition, we are considering DF heat pumps. The house will need 2 or 3 to be zoned correctly. Please let me know about the duct placement and thank you for your help?

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Air Handler Water Coil Freeze Stat | Freezing Protection Control 5/5 (1)

Air Handler Water Coil Freeze Stat - Freezing Protection ControlAir Handler Water Coil Freeze Stat

Air Handler Water Coil Freeze Stat – The HVAC Air Handler Freeze Stat is a low temperature limit control and it is used mainly in commercial systems in the duct work on economizers or in air handlers just before any coil especially water coils. It is a safety and protection control to prevent extremely cold air from reaching the hot water or chilled water coils inside the air handler where the air enters from the economizer. Under ideal control set up if the freeze stat trips the economizer dampers close and the blower fan stops. This prevents coils from freezing. A frozen coil can bust open and will need to be replaced if it freezes thus the purpose of the freeze stat in HVAC air handler applications which utilize economizers for free cooling.

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Find Tonnage on AHU | HVAC Equipment Nomenclature 5/5 (1)

Find Tonnage on AHU | Equipment Nomenclature

How do I find out the tonnage on a AHU? The label/tag has faded all I have on file is the model number and the serial number, make.

Question Posted By Francisco the Building Engineer on May 3, 2011

Refer to the manufacturers website for their HVAC nomenclature of model number and serial numbers and how those numbers correspond to the tonnage and other technical data. Or you can call your local dealer for the manufacturer and they will tell you.

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Refrigeration for HVAC | Air Conditioning and Heat Pumps 5/5 (1)

Refrigeration for HVAC

Air conditioners and heat pumps use the process of refrigeration to provide heating and cooling. What is the definition of the process of refrigeration? Refrigeration is the process of moving heat and depending on whether it is a heat pump or air conditioner and what mode it is in will depend where you are moving the heat. An air conditioner and a heat pump (in the cooling mode) will move heat outside. The evaporator coil absorbs the heat and the condenser rejects the heat.

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About Chilled Water Systems | HVAC Hydronics No ratings yet.

About Chilled Water Systems | HVAC Hydronics

About Chilled Water Systems

About Chilled Water Systems
Old York Chiller

Chilled water systems are mainly used in large commercial HVAC air conditioning systems and industrial cooling applications although there are some residential and light commercial HVAC chilled water systems in use. Chilled water systems are popular because they use water as a refrigerant. Water is far less expensive than refrigerant. This makes them cost effective especially in commercial HVAC air conditioning applications. Instead of running refrigerant lines over a large area of the building water pipes are ran throughout the building and to evaporator coils in air handlers for HVAC air conditioning systems. The chilled water is pumped through these pipes from a chiller where the evaporator coil absorbs heat and returns it to the chiller to reject the heat.

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Air Conditioner Condensation Water Dripping – Condensate Leaks 5/5 (1)

Air Conditioner Condensation Water Dripping

Air Conditioner Condensation Water Dripping – It’s the heat of summer or even the beginning of the season when you first turn on your air conditioner. Hopefully you’ve already had all the preventive maintenance checks done and there are no problems. Everything is working fine at least for now. Suddenly you notice water around the air conditioner and you know you have a problem. This problem is often referred as an air conditioner condensation water leak and often customers call an HVAC contractor and say their air conditioner is leaking water. This is not a unique problem and many people have dripping air conditioners during the season. Here are the likely reasons why your system is dripping water. Hopefully the AHU evaporator coil is not in an attic because you could be buying a ceiling unless precautions were taken. Your air conditioner has a condensate problem.

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Condensing Unit Frozen Wont Turn Off 5/5 (1)

Condensing Unit Frozen Wont Turn Off

What you can expect to learn from this article: this article is an answer from a question taken from our email by a visitor to High Performance HVAC. We often use the questions we get in the email as a guide to write articles. The topic is a condensing unit that will not turn off and it is freezing up. From my experience in the field and using my HVAC knowledge I offer the readers a list that could cause this problem. We hope it helps you.

What’s the possible problem with a frozen air conditioner condenser that won’t turn off except with the breaker?

Related Link: Here is a similar but different problem with a frozen air conditioner.

The Answer for frozen air conditioner condensing unit that won’t turn off –

There are 3 possible problems with this unit and will probably need the attention of an HVAC Technician for repair. Here’s the 3 possible problems:

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HVAC Compressor Failure – Air Conditioner Repair No ratings yet.

HVAC Compressor Failure – Air Conditioner Repair What you will learn from this article: 1) discussion about HVAC compressor failure and how it is one of the most expensive air conditioner repairs 2) comprehensive list of reasons why HVAC compressors fail 3) actions to take to prevent compressor failure 4) the importance of doing the … Read more…

Air Handler Components 3 | HVAC Air Handling 5/5 (1)

Air Handler Components: Hot Water Coil Heat

Air Handler Components 3Air Handler Components – Hot water coils inside of air handler units combine a boiler system or a special capacity hot water heater and forced air to provide forced-air heating. The concept is simple and used a lot in commercial and some in residential. Commercial systems almost exclusively use a boiler to provide hot water to the hot water coil inside the air handler unit while the residential systems use mainly special capacity hot water heaters to provide hot water to the hot water coil inside the air handler unit. On a call for heat a pump is energized to begin the circulation of hot water from the heating source to the coil. The air handler unit blower motor energizes and air begins to move across the coil. Heat is exchanged from the hot water coil to the air and the air is delivered to its appropriate destination through the ductwork.

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Start Capacitors for HVAC Compressors | Motor Start Assist 5/5 (1)

Start Capacitors for HVAC Compressors

Start Capacitors for HVAC Compressors - Start Capacitor with Potential Relay
Start Capacitors for HVAC Compressors – HVAC single phase compressors always come hooked up to a run capacitor to help the compressor when it is running however very few HVAC compressors come with a start capacitor. Most HVAC technicians know that the air conditioner or heat pump compressors pulls a lot of amps on start up and this large amount of amperage draw on start up is referred to technically as locked rotor amps or inrush current and can be as much as 40,000 watts or more of pure power to get an HVAC compressor started. That large amount of amperage on the compressor windings over and over again can slowly degrade or eat away at the life of the compressor as it starts over and over again during the summer for the air conditioner and year round for the heat pump. The run capacitor does little to help the compressor on start up so in certain circumstances the manufacturer will recommend installing a start capacitor on new installations and it is a prudent thing to add a start capacitor to older installations where we need to give the compressor a slight boost on start up. There are two ways we can do this job of helping the compressor start. The first method is usually for older installations on compressors that are having issues starting and most technicians use this method when they encounter a compressor with problems. The technicians use a hard start kit which is usually available at the local HVAC supply house and is easily hooked up to the compressor wiring following the directions on the hard start kit wiring diagram. Of course every HVAC tech knows it is important for safety to turn off the power to the unit and discharge any capacitors before proceeding otherwise serious injury or worse can occur.

Motor Capacitors Available here for Purchase

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Air Conditioner Condensate Problems – Condensation Drain Plugged 5/5 (1)

Air Conditioner Condensate Problems

Labor time (approximate): 1 hour in some cases, several hours in others

Air Conditioner Condensate Problems – Condensation Drain Plugged
New Air Handler with Secondary Condensation Pan Under Unit and Showing the Float Switch

Air Conditioner Condensate Problems – It is important for air conditioning preventive maintenance to be performed on your system to avoid problems. Condensation water leaking near the air handling unit can be avoided with proper air conditioning repair and preventive maintenance. Normally this is a very simple problem that can be fixed in less than 30 minutes. Here is a list of what can cause water around the outside of the air conditioning air handler unit.

We have many other related articles. Please use the search feature to the right to help you find other related articles.

Air Conditioner Condensate Problems – Possible Causes

  • The black insulation (called Rubatex) has a tear in it or doesn’t cover the entire suction line. This line normally (in Air Conditioning air condition mode) operates below the dew point and will sweat if it is not insulated. It must have a sealed vapor barrier to be effective.

Nu-Calgon 4296-60 Pan-Treat Scum 200 Tablets to prevent drain clogs for condensate pans available here

Air Conditioner Condensate Problems – Condensation Drain Plugged

  • The insulation surrounding the air handler supply transition or ductwork is torn. The supply transition and duct can operate (under the right conditions) below the dew point and sweat. It is important that the transition have a vapor barrier around it. This scenario is especially true for those that have over sized units.

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Furnace Water Leak Possible Condensate Problem No ratings yet.

Furnace Water Leak Possible Condensate Problem

Richard,

My furnace is leaking water and it is summer time so I am not using it for heat except for the blower fan which is hooked up for the air conditioner and the heat. I know the pipes from the outside units run into a box on top of the furnace so I think that is a part of the air conditioner. What can I do to fix the problem if you know what the problem is by my explanation here? Dan

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Cooling Tower Evaporation Cools Water | HVAC Technical No ratings yet.

Cooling Tower Evaporation Cools WaterCooling Tower Evaporation Cools Water | HVAC Technical

Cooling towers use the process of evaporation to cool or removes heat from the condenser water that was transferred to the water in the chiller condenser barrel. The heat is absorbed at the load in this case in a data center on a data center floor. The servers and electrical equipment produce a massive amount of sensible heat. The heat is absorbed by computer room air conditioners or computer room air handlers. These systems, computer room air handlers and air conditioners, have chilled water coils. The chilled water originates at the chiller into the primary loop. The water circulates through the primary loop and makes its way into the secondary loops.

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Large Condenser Pump for a Chilled Water System No ratings yet.

Large Condenser Pump for a Chilled Water SystemLarge Condenser Pump for a Chilled Water System

This large HVAC condenser pump serves a new chiller located in a data center. This pump pumps condenser water through the condenser chiller barrel and to a cooling to reject the heat absorbed in the chillers evaporator barrel. The pump works to move the water from the chiller to the cooling and then back through the chiller again. The water is diluted with a glycol solution to prevent freezing in the winter time when the chiller needs to run at low ambient temperatures.

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