Common and Hard to Find HVAC Parts and Appliance Parts

Friday, August 9, 2013

HVAC Terms

HVAC Terms

Have you ever had a service technician come to your house and make a repair only to discover that the part that they supposedly repaired is one of which you have never heard. Here is a quick reference guide for the next time that a service technician tells you that he needs to order a thermostatic expansion valve or that you are not getting enough CFMs.

A - Coil This heat exchanger depends on two coils, placed diagonally and then connected in the middle. The result is a coil that looks like the letter “A”.
AC This electric current rapidly changes its direction of flow. See also DC (Direct Current).
AC or DC These abbreviations stand for Alternating Current and Direct Current, and represent forms of electrical circuiting.
ACCA Air Conditioning Contractors of America.
Acoustical A derivative of the word “acoustic”. When a system is acoustical, it makes or conducts sound well.
AFUE This yearly measurement is an efficiency test of the conversion of fuel to energy by a furnace. A high rating on an AFUE test indicates a good furnace. Service Champions technicians can do AFUE tests.
AGA Abbreviation for American Gas Association, Inc.
Air Cleaner Also known as an air filter, this equipment removes dust, debris, and other particles floating in the air. When air moves through the air cleaner, these particles are caught.
Air Conditioner This system is usually placed outside the home, and controls the humidity, ventilation, and temperature of the air inside.
Air flow Volume This is a measurement of an air conditioner’s output. Airflow volume is calculated by measuring the cubic feet per minute that the air conditioner circulates.
Air handler This piece of the air conditioning system regulates and directs air throughout the ductwork, spreading heated or cooled air through the home.
ARI Air Conditioning & Refrigeration Institute.
ASHRAE American Society of Heating, Refrigeration and Air Conditioning Engineer
BTU British thermal unit. The standard of measurement used to guage the amount of heat required to raise the temperature of one pound of water by one degree (Fahrenheit).
BTUh Equal to about 1.06 kilojoules, this measurement is taken in heating and cooling when assessing the power output of an air conditioner or furnace. BTU measurement can also be taken by the hour, and are known as BTUh.
Burner This piece of a furnace conducts heat using electric or gas fuel.
Burner (sealed combustion) A piece of a furnace that conducts heat using the air outside of the system.
Burner Orifice The piece of the burner that inputs gas. The gas is then mixed with air and used as fuel.
Capacity The capability of a heating or cooling system to fill a required space.
Celsius The metric scale of temperature. When measured on water, the freezing point is 0 ̊C, and the boiling point is 100 ̊C. Conversion from Celsius to Fahrenheit is as follows. Multiply by 9, then divide by 5, then add 32
CFM - (Cubic Feet per Minute) The airflow rate in an air conditioning system.
Charge The process of adding refrigerant to an air conditioning system. Refrigerant is stored in a sealed system and aids in the overall cooling factor. Refrigerant moves from the indoor evaporator to the outdoor condenser and then back to the indoor evaporator.
Compressor The piece of equipment pumps refrigerant through a sealed system.
Condensate The process of a chemical that changes from its vapor form to its liquid form.
Condenser coil (or outdoor coil) Also known as an outdoor coil. This piece of the air conditioner removes heat from refrigerant in vapor form. When the heat is removed, the refrigerant becomes liquid and moves back to the inside of the machine.
Condenser Fan This piece of equipment cools the condenser by blowing air on it.
Contactor This piece of equipment cycles electrical current. A contactor switches on and off; connecting and breaking an electrical current.
Crankcase Heater A piece of equipment that maintains the vapor form of refrigerant in the crankcase part of the system. By heating the crankcase oil to a higher temperature than the coldest part of the system, refrigerant remains in its vapor form.
Damper A plate that opens and closes to regulate air flow through the ductwork system.
DC - (Direct Current) This electric current travels in a direct route. See also AC (Alternating Current).
Defrost The process in which removes frost buildup from the outdoor coil. This usually takes place when the weather is cold and the air conditioner is not in use.
Degree day Measurement of required for an amount of space. It is equal to the outside temperature minus 65 ̊F.
Dehumidifier This piece of equipment extracts humidity from the air. It cools air to the point where water turns from vapor to liquid form and then removes the liquid.
Diffuser Placed over ductwork, this part separates air with vanes going in differing directions.
DOE Department of Energy
Down flow Furnace This type of furnace processes air from top to bottom.
Drain Pan This part catches any condensate left in the machine. Not all machines need a drain pan.
Dry Bulb Temperature A measurement of heat intensity independently of humidity. A dry bulb thermometer takes this measurement.
Dry Bulb Thermometer An device that measures air temperature independently of humidity.
Ductwork This system of pipes transports heat from the central air conditioning or heating system to the rest of the building.
DX This refers to the expansion of refrigerant. This process conducts heat.
EER This is a measurement of the cooling capacity of an air conditioner. BTUh: electrical watt input.
EPA This Federal Agency encourages the use of eco – friendly, non –pollutant, and energy efficient equipment in every sector, including heating and air conditioning.
Evaporator Coil (or Indoor Coil) Also known as the indoor coil, this piece of equipment removes heat and humidity from the air inside the building.
Expansion Valve This part measures the pressure and temperature of refrigerant.
Fahrenheit This temperature scale is used mostly in the United States. When measured in water, the freezing point is 32 ̊F and the boiling point is 212 ̊F. Conversion to the Celsius temperature scale, use the equation below: Deduct 32, then multiply by 5, then divide by 9
Fan This piece of equipment uses motion to create an air current.
Filter This part removes particles of dust and other debris from the air. (See MERV Rating).
Flue This part of the equipment vents out exhaust gases.
Furnace This heating system uses fuel to produce heat for a building.
Fuse This part protects against overcurrent. When too much electricity is running, the fuse melts and breaks the current.
GAMA Gas Appliance Manufacturers Association.
Gas Furnace Heat Exchanger This part of the system moves heat from inside the furnace into the air outside the furnace. The duct system transfers this air to rooms in the building.
Heat Exchanger The part of the system allows heat to be transferred from the hot parts of the machine to the cold parts of the machine.
Heat Gain This is a total amount of heat an area receives from all heat conducting machines including furnaces, appliances, lighting, respiration and solar energy.
Heat Loss This is a measurement of the rate heat escapes from the inside of a building to the outside of the building.
Heat Pump This compressor cycles hot or cold air to the building.
Heat Transfer The process where heat moves from one area to another.
Heating Coil This part of the system conducts heat.
Hertz The measurement of electrical energy per second. Standard frequency is 6- Hertz.
HSPF - (Heating Seasonal Performance Factor) The measurement of heat efficiency over the period of a heating season.
Humidifier The sensor which measures and regulates humidity.
Humidistat The sensor which measures and regulates humidity.
Humidity The measurement of moisture volume in the air.
Humidity, Absolute The ratio of humidity between saturated and non – saturated air. It is taken by measuring the grams of water vapor in 1 cubic meter of air.
Humidity, Relative The ratio of current humidity to the humidity if the air were 100% saturated.
HVAC - (Heating, Ventilating and Air Conditioning)
Ignition Beginning of the combustion process, ignition requires a gaseous mixture to take flame form.
Kilowatt (kW) The electrical measurement of 1,000 watts.
Latent Heat The type of heat that controlled the state of a substance rather than the temperature.
Media The part of an air filter which traps dust particles, debris and other impurities in the air. This can be made of fiberglass, polyester, dog hair, blue/green, and charcoal, among other materials.
MERV rating (Minimum Efficiency Reporting Value) Numbered from 1 to 16, this measurement gives the efficiency value of an air filter.
NEC National Energy Council / National Electric Code NEMA National Electrical Manufacturing Association OEM Original Equipment manufacturer
Package Unit This smaller heating or cooling unit is used for residential purposes and is usually located on the roof or in the attic of a house. It can be moved without disconnecting any refrigerant lines.
PSI Pounds per square inch
PSIA Pounds per square inch, absolute.
PSIG Pounds per square inch gauge
PVC - (Polyvinyl chloride) This plastic is used more frequently in buildings.
Reciprocating Compressor This piece of equipment work directly with the crankshaft to highly pressurizes gases.
Refrigerant The chemical used to cool air. It expands to vapor form, gathering hot air, and then contracts to liquid form to cool the air.
Refrigerant Charge The required amount of refrigerant in a system.
SEER The measurement of seasonal or annual heating or cooling efficiency. This rating is used nation – wide and is a good indicator of operating cost.
Self Contained System (See Package Unit)
Sensible Heat The type of heat the affects the temperature of a substance.
Sensor The piece of equipment that measures and regulates changes. Air conditioning and heating sensors measure the air temperature and humidity among other things.
Setpoint Part of the thermostat, this is the indicator of the desired indoor temperature.
Spine FinTM Coil The aluminum outdoor coil made of tiny spines. This creates a greater surface area, which improves heat exchange efficiency. This technology is patented.
Split System The combination of an outdoor unit and an indoor unit. This is the most common type of system.
Thermostat This system monitors and regulates a heating or cooling system.
Ton The measurement of the cooling capacity of a heating or cooling system. A ton of energy can melt a ton of ice in a 24-hour period.
Two-stage (cooling and heating) An air conditioner designed to operate on high and low settings during different weather. The high setting is used during more extreme weather, and the low setting is used during more moderate weather. This type of air conditioner is in use for a longer period of time, and produces a balanced temperature.
TXV - Thermostatic Expansion Valve The piece of equipment that meters the flow of liquid refrigerant into the evaporator while also measuring the vapor refrigerant leaving the evaporator
U-Factor This refers to the resistance of heat flow through building materials
UL Underwriters Laboratories.
Upflow Furnace A furnace that operates air from bottom to top.
Vacuum A pressure below atmospheric pressure. 30 inches Mercury (periodic symbol "Hg") is a perfect vacuum.
Variable speed motor(s) A type of fan that adjust speed according to the need of operation. This contributes to efficiency and performance of the machine.
Volt Measurement of electrical force given to the electrons in an electric circuit.
Voltage The force that pushes electrical current along wires and cables.
Watt A unit of electrical power. It is equal to the flow of one amp at a potential difference of one volt, and does the same amount of work as 1 joule.
Wet Bulb Thermometer A sensor that measures gas and vapor in the air using a bulb covered in a water soaked cloth.
Zoning System This system sections a building into zones that can be controlled independently of each other

Saturday, December 15, 2012

Why do air conditioners freeze up?

Each year as the first warm days of summer roll in. Thousands of people across the country find themselves confronted with the same problem. As the air conditioner begins to run alot it covers in ice and begins to blow warm air. This obviously provides no relief on a 100 degree day and renders a cooling unit worthless. Many who find themselves in this predicament face the questions, "what causes my air conditioner to freeze up?" and "what can I do about my air conditioner being frozen?". These are the main reasons that your unit freezes up.

Air Conditioners Freeze Up Because of Air Flow Problems

Several things fall under this category including a stopped up filter, dirty coils and problems with the fan motor. We will begin with best case scenario and work our way toward the more major problems with regard to airflow.

Air conditioners freeze up when the air filter has not been changed

It would seem that this goes without saying, but change your air conditioner's air filter regularly. By not doing this you invite many potential problems. People frequently ask how often they should change their air filter, but there is not a hard fast answer. While every house and every filter is different, as a rule standard one inch or two inch filters should be checked every 30-60 days and four inch and five inch filters should be checked every 3-6 months. When a filter appears dark or dust covered it should be changed immediately. When a dirty air filter is not changed it causes the blower to work harder and eventually will cause the unit to trip a breaker or freeze up. Change your air filter, run the fan on your air conditioner for one hour (not in cooling mode but fan only) and see if your this fixes your problem. After running the fan for one hour, your unit should cool whether this was the problem or not. If after running for a couple of days the unit does not refreeze, the problem is solved. I the air conditioner does freeze up again perhaps your coils are dirty.

Air conditioners freeze up when the evaporator and condenser coils are dirty

Air conditioners like any piece of machinery require regular maintenance. If your unit has not received a maintenance visit in the past year then your unit may freeze up because of poor air flow. Everyday a central heating or cooling unit will circulate all of the air in a house. This means that everything in the air including dust, smoke, carpet follicles, dead skin and other contaminants travels through the indoor evaporator coil everyday. A standard air filter catches what it can but inevitably dust and dirt in small particles lodge themselves in the coil. Consider the example to the left showing an evaporator coil before and after cleaning. The air that you breathe filters though this coil every time that your HVAC unit runs. If the air has difficulty getting through this coil your air conditioner will cover in ice. If you are concerned that dirty coils are causing your unit to freeze you can contact a local HVAC contractor or you can purchase an appropriate coil cleaner and attempt to do this job yourself. If you need assistance choosing and obtaining the appropriate cleaner please contact PilotAirHVACparts.com.

Air conditioners freeze up when a fan motor is not running

Though you may have assured that the filter in your system is new and proper maintenance has been completed, it will be to no avail if your indoor blower motor is not operating properly. If your fan motor is not coming on it may be the result of a defective motor or it may simply require a replacement capacitor or relay. If an evaporator fan motor is running but is not at the proper speed or is not operating on its proper cycle, this will also cause a frozen air condition unit. A local contractor can help determine which of these problems you need to address and even fix them if you like.

Air Conditioners Freeze up Because of Refrigerant Problems

Ideally when your air condition or heat pump unit is frozen up it can be diagnosed as an airflow problem and easily repaired. Unfortunately, this is often not the case. Refrigerant problems are the most common cause of an HVAC unit freezing up and require handling by a CFC certified professional.

Air Conditioners freeze up because of a low refrigerant level

There are a number of reasons that a unit may be low on refrigerant. If a unit is less than a year old, it is possible that the charge was never set properly upon installation. Licensed HVAC contractors are careful to set the refrigerant level according to the proper high and low side pressures, but even the best sometimes have difficulty getting the levels right on extremely hot or cold days. Another reason that the refrigerant level may be low is a cracked or leaking valve. A leaking access valve or valve stem can normally be replaced by a professional for $10-$50. Often a low refrigerant level indicates a leak in the lineset or coil. If this is the case with your system, a repair should be made immediately. While many people feel that adding "freon" or another refrigerant is a regular part of having an air conditioner or heat pump, this should not be the case. Adding refrigerant to a system with a leak is like putting air in a punctured tire; it may get you by but the problem still persists. R22 is the most common form of refrigerant in older systems and is known to cause environmental hazards when it escapes through a leaking coil. R22 can cost in excess of $100 per pound as the EPA phases out the production of this freon and newer refrigerants can also be costly. So it can become very expensive to repeatedly charge your HVAC system. If a system has a refrigerant problem, it should be addressed immediately by a professional, and the equipment may need to be replaced.

Air Conditioners freeze up because of a problem with the TXV or Piston

Most cooling systems have some way to regulate the flow of refrigerant. The most efficient systems use a TXV (Thermal Expansion Valve), but lower grade systems will often use a simple piston. Expansion valves may become stuck in the open or closed position rendering them defective and making it necessary to replace. Both pistons and TXV can become ineffective by the introduction of trash, small particles or moisture to the refrigerant lines. While some systems contain filters to avoid any such particles causing a problem, many others do not. If a piston or TXV must be replaced the bill can often run between $300 and $800. This repair, like the diagnostic of a low refrigerant level should be completed by and experienced service technician that is familiar with brazing and refrigerants.

Wednesday, November 21, 2012

Lennox Nomenclature

While HVAC contractors often install one brand such as Trane, Lennox, Rheem or Goodman they can often find themselves as experts in servicing their brand but lacking in general information concerning other brands which they service. To provide assistance with this challenge we will be recapping some of the more common questions associated with the various brands. One of the frequent questions that we hear at PilotAirHVACparts.com is "what does this model number mean." The information listed below will give a good understanding of the Lennox nomenclature which will allow you to know when and where a unit was made in addition to basic unit information. Stay tuned for upcoming posts concerning the nomenclature of other brands and please keep us in mind when you need Lennox parts.

Saturday, November 10, 2012

Honeywell Thermostat Manual - 7 day programmable

Honeywell makes some of the best products on the market when it comes to thermostats. While Honeywell offers several lines of thermostats, for this post I will focus on the contractor focusPro series. This line of HVAC controls is only available to contractors through warehouses that furnish the heating and air conditioning community with parts and supplies. This line is NOT the same set of thermostats that you would find at your local hardware store or an area big box store. If you are looking for a direct replacement for one of these thermostats you must purchase it from a supply house, if you are a contractor or from a contractor, if you are a homeowner. You may also purchase any of these programmable or non-programmable thermostats online. The full line of stats that they offer include builders grade models (which provide one of the cheapest thermostats) such as the PRO 1000 Non-Programmable Thermostat as well as energy saving options such as the Honeywell Vision PRO 8000 7-Day Programmable Thermostat. Below are the manuals for the 7 day programmable.

Because the Honeywell Focus Pro series of thermostats is available exclusively to HVAC contractors many people do not realize that one can find a print a complete Honeywell thermostat manual online. Manuals and instructions on the full line of heat pump thermostats, oil furnace thermostats and gas furnace thermostats will be available in future posts. Choose which thermostat manual you need below. These manuals are free, downloadable and printable.