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.
Variable Speed ECM Condenser Fan Motors are used in condensers for the high efficient models so that the fan speed for the condenser can be modulated according to the load of the system. The ECM fan motors are used in condensers that either have a modulating compressor or condensers that have two compressors where one compressor is small and one compressor is large. The ECM motor adds to the efficiency of the system by modulating the condenser fan motor to match the compressor use needed to satisfy the load.
Variable Speed ECM Condenser Fan Motors – Peak Operation
On very hot days you need more air conditioning capacity to satisfy the heating load demand put on your home in the summer. In milder weather you do not need to run the air conditioner at 100% to satisfy the higher demand. HVAC equipment manufacturers have introduced systems that have the ability to run in two-stages so that on the hotter days you can satisfy the demand and on the cooler days you can run the system at a lower setting thereby using less energy.
Condenser Fan Motor Repair | Air Conditioners & Heat Pumps
What you will learn from this article:
1) Specific description of a condenser fan motors job along with some technical details
2) Air Conditioner & heat pump condenser fan motor operation
3) Condenser fan motor troubleshooting basics
4) Condenser fan motor repair warning and disclaimer – Turn the power off before working on the fan
5) Replacing or repairing the motor
6) Why you should replace the capacitor when you replace the motor
7) Conclusion along with lots of resource and related links so you can take a closer look and learn more.
The condensing unit fan is responsible for pulling air through coils of the condensing unit. They pull air through the condensing unit coils. It runs the gamut in horsepower ratings from low fractional horsepower in small residential units all the way up to 1 horsepower (and larger) 3 phase motors in large commercial HVAC units.
It is usually direct drive to a propeller blade which creates the air flow. Its job it to move air. A specific quantity of air through the condensing unit coils so that a heat exchange process can take place and rig the condensing unit of the heat it absorbed indoors or in the case of the heat pump in heating mode to absorb heat from the outside air and send it inside.
It is the process of refrigeration and all the components work together to achieve one result and that is to move heat from one place to another.
A Closer Look – The classic definition of refrigeration is to move heat from one place to another. The condenser fan motor is an essential part of that process. Take a closer look at the HVAC Refrigeration
This article is archived for future records. Please refer to DOE website for reference on current energy efficiency guidelines.
10 SEER units cannot be purchased in the US any longer. The new standard as mandated by the Department of Energy as of January 2006 is 13 SEER. This 30 percent increase in efficiency from 10 SEER requires a change out of the inside coil. In 2011 the Senate is proposing a new SEER and AFUE standard that will be based on where you reside in the USA. The country will be split up into three regions. Northern, Southern, and the Southwestern regions with each region having different efficiency standards. The proposed efficiency standards for each region are as follows:
Glycol Feed System for Chiller Condenser Water Loop
Glycol is like antifreeze and is used in chilled water piping loops to prevent freezing. Everyone knows when the pipes freeze they also break and start leaking. Having antifreeze in a chilled water loop is important to prevent freezing. So, how do you keep antifreeze in the loop when the water/glycol mix goes out to the cooling tower and there is a loss of water/glycol through windage or drift? Meet the glycol make-up unit where it can automatically be added to the loop and prevent freezing. Antifreeze make-up units range from automatic units that will inject the antifreeze right into the loop to manual units that require an operator to control the process of adding antifreeze to the water loop. These make-up units make it easy to add it to the loop without having a shut-down of the chilled water loop it serves so the loop can continue to run while the glycol is injected directly into the loop. The loops are designed to work at low ambient temperatures need the water/glycol mix to prevent freezing especially for critical facilities like data centers that need to remain operation no matter what the outside temperature conditions are. Percent of antifreeze to water depends on the expected operational temperatures outside so the mix is important for expected operating temperatures. An example of this is listed in the following table (follow equipment manufactures instructions for the recommended mix of antifreeze to water for temperatures):. Each loop requires a different ratio of mix based on ambient conditions, flow rates and other factors for determining the proper mix ratios.
Glycol Feed System for Chiller Condenser Water Loop | Antifreeze Protection – Percentage Water to Temperature Ratio
Programmable thermostats can save you more than ten percent on your homes utility bills. For that reason a programmable can pay for itself within a few years depending on the type and expense of the type you purchase. I always lean towards Honeywell thermostats simply because I’ve seen their reliability in the field and sometimes ease of use. Among others, you can expect good quality from Honeywell thermostat products. The new, hi-tech style currently out on the market is the Honeywell touch-screen thermostat.
The National Electrical Code (NEC) and HVAC: The Basics
The NEC and HVAC Chapter Two
The NEC and HVAC Chapter Two – Chapter Two of the National Electrical Code (NEC) covers Wiring and Protection and starts at Branch Circuits, Feeder circuits, GFCI requirements and protection,. An HVAC installer may want to pay attention to branch circuit requirements. Article 220 in Chapter two of the NEC includes calculations for branch and feeder circuits including service calculations. (Table 220.3)
Specific branch circuit requirements for HVAC can also be found in Chapter 4 Article 440 – Air Conditioning and Refrigerating Equipment Branch Circuit Conductor Sizing
Article 424 – Fixed Electric Space Heating Equipment Branch Sizing
An entire chapter on motors including feeder circuits for motors
Chapter Two of the NEC also covers basic lighting which by code is done by Volt-Amperes per square foot. (Table 220.12)
Data Centers a categorized by tier levels and everything in the data centers infrastructure is checked and classified so that any particular data center can achieve a certain tier level based on the infrastructure in the data center. Data centers are always classified a critical facilities and need the proper infrastructure to maintain a critical level of performance to minimize any downtime that may occur as a result of a failure in one of the data centers systems or a failure of any utility serving a data center. HVAC Mechanical and electrical systems are redundant in most data center facilities and are scrutinized for dependability and reliability. A data center can have two chiller plants (one redundant) but what happens if the data center relies only on one source for the make-up water for those chiller plants? Say a local municipality supplies the water used for make-up water what happens if a main breaks in the middle of the summer when demand for make-up water is high? A redundant chiller plant is no good if the cooling towers do not have water to keep the condenser water cool. Data centers therefore typically have back-up sources for make-up water like a well system or even make-up water tanks that will carry the data center a few days until the utility can be restored.
This Goodman 13 SEER Heat Pump condensing unit is a new installation. The inside Goodman air handler attached to the heat pump condenser via line set was also replaced with this new Goodman heat pump. Its not a good idea to put a new high SEER air conditioner or heat pump condenser without matching it up with a properly rated and efficient air handler especially the coil. In 2006 congress mandated new efficiency levels for split system air conditioners from 10 SEER to 13 SEER. HVAC Manufacturers could no longer sell 10 SEER split system air conditioners or heat pumps to the general public. As a result homeowners were forced to purchase HVAC Equipment that was more efficient which of course costs more to manufacture. Additionally, in the past HVAC contractors could change the condenser if the condenser went bad. The HVAC Contractor could hook up a new condenser to an older air handler before this rule took effect. After the new rule took effect in 2006 the HVAC contractors had no choice but to replace the condensing unit and the air handler as the the older systems rarely matched the newer systems.
This is a secondary chilled water pump in a large pump room designated for pumps and piping in a data center. After a few minor tweaks and corrections these pumps all operated flawlessly. There was very little issues with the secondary pump start-ups unlike the primary pumps where cavitation was encountered on the primary chilled water pumps and the condenser water pumps for the chiller. The diagnosis for the cavitation of the primary pumps and the condenser water pumps was that the loops were not properly purged and this caused those pumps to cavitate. The secondary pumps, pictured here, did not have that problem giving kudos to the team that purged the loops on this side of the chilled water system.
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.
What you will learn in this article:
1) What thermostat wire color is likely to go to which terminal on the thermostat
2) The function of each wire terminal on the average thermostat highlighting some of the differences in those functions from manufacturer to manufacturer
Thermostat Wire Colors Code – Always follow the thermostat manufacturers instructions whenever changing the thermostat. Always turn the power off at the air handler and the condenser and make sure there is no voltage at the transformer before proceeding. The thermostat wire colors below are the most likely colors used for most installations however your thermostat wire colors may be different than what is indicated here. There is no official standard for thermostat wire colors. Thermostat wiring colors are not standardized but these are the most wiring methods used based on my years of experience in the HVAC field where I successfully wired a lot of thermostats. Honeywell Thermostats Available Here
York Affinity Versus Carrier Infinity Air Conditioners
Every manufacturer has there own parts system and sometimes these parts are readily available aftermarket and sometimes the parts are proprietary and can only be purchased through manufacturer of that equipment. Carrier is one of the HVAC manufacturers that has proprietary parts and sometimes you will pay a premium for those parts.
The manufacturer can hold the customer hostage especially when it comes to repairing the unit. Of course York is one of the big HVAC manufacturers and they too have proprietary parts however the parts are usually more reasonable for purchase as far as cost is concerned so people would lean towards purchasing a York simply because the replacement parts are are not sold at a premium where with SOME Carrier parts are sold at a premium and are not easily replaceable except through a Carrier dealer.
The first thing we need to do when comparing a Trane Versus a Carrier is to make sure we are comparing similar models with similar features. Each manufacturer makes various models from a builder’s grade unit which is usually the HVAC manufacturer’s cheapest model all the way up to the unit that has bells and whistles and some of these have bells and whistles for the bells and whistles. You simply want to make sure you are comparing apples to apples and not an apple to an orange.
The next thing we need to do when comparing HVAC equipment is to look at the HVAC contractor installing the equipment. If you get a lousy installer or contractor forget about name brand because the HVAC system WILL NOT FUNCTION PROPERLY if it is not installed properly. Also the unit will not have the same life expectancy and will fail prematurely and will need to be replaced sooner than if the HVAC equipment is installed properly in the first place. Out of any advice about air conditioning and heating equipment that someone can give you this is probably the most important part.
Heat Pump Frost and Ice Build Up | HVAC Troubleshooting
Heat Pump Frost and Ice Build Up – Hi. I noticed my that one of my outside heat pump condensing units was laboring throughout the night. This morning I found ice frost buildup on the heat pump condenser fins. I live in Tucson, Az. It has been colder than normal (below freezing) with a bit more moisture in the air than usual as of late. Can you please tell me what causes this frost ice buildup, and how I go about rectifying? Does this mean that the condenser pump is shot? I’m originally from the Midwest, and have never experienced this before. What should I be doing? Thank you for your help.
Heat Pump Frost and Ice Build Up – The answer……………
It sounds to me like you have a heat pump and this is normal for frost to build up on heat pumps. I would guess that in Tucson they set the heat pump defrost cycle times pretty high as it is dry there. If you have a lot of ice build up on the heat pump then there is a problem with the heat pump defrost controls but if the heat pump frost problem is just intermittent then everything is working fine and defrosting as designed.
Old Leaking Condenser Coils (also referred to as freon leaks) can cause serious issues with HVAC heat pump equipment. HVAC refrigeration circuits are designed and built to hold the refrigerant. It is a sealed hermetic system. The HVAC refrigeration circuit should never need refrigerant. An HVAC refrigeration system does not burn refrigerant. The refrigerant is used over and over again to move heat from one place to another. Aside from a leak, once the refrigeration system is properly charged, the system should never need refrigerant for the life of the equipment.
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?
This chilled water unit is a new ammonia chiller. This unit is also unique in that it has no compressor. Instead it uses the chemical properties of ammonia and heat from natural gas to condense the refrigerant which is ammonia. A chiller provides chilled water to a chilled water loop. Cold water is circulated through a loop where it is direct into a coil in an air handler. Air is blown across a coil where a heat exchange process takes place. The air handler discharges cool conditioned air throughout a duct system. Chilled water systems are typically used in commercial air conditioning applicationsbut there are some chilled water systems in residential applications.
Air 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.
This condensing unit was too close to the house to effectively reject heat. It was a bad HVAC condensing unit installation job by the HVAC installers. A mechanical inspector rejected the final for the permit until the condensing unit was correctly installed. It is recommended that condensing units have at least 2 feet of space so that it can effectively reject heat. It needs space to breathe and pull air into the coils so that there is a proper heat exchange taking place when it is running. On this air conditioner condensing unit there are four sides to the unit. By installing the air conditioner condenser too close to the house the installer effectively reduced the capacity of this unit by nearly one fourth which will cause problems with unit in the way of higher head pressures and that will cost the homeowner more money in the long run.