Refrigeration Pressure Switches | HVAC Systems

 Refrigeration pressure switches -

Refrigeration Cycle Component Diagram for Air Conditioners and Heat Pumps

Refrigeration Pressure Switches | HVAC Systems

Richard – What are pressure switches used for in refrigeration circuits and how do pressure switches protect the system from further damage?

Refrigeration Pressure Switches

Thanks for the question and for being a reader of High Performance HVAC! First there two types of basic refrigeration switches in the typical high grade residential system. I say high grade because not every refrigeration system in air conditioners and heat pumps have switches to protect the refrigeration system. Continue reading

Variable Speed ECM Condenser Fan Motors | HVAC Refrigeration

Variable Speed ECM Condenser Fan Motors - High SEER Trane Condenser Variable Speed ECM Condenser Fan Motor

This high SEER Trane condenser uses an ECM variable speed fan motor to modulate the speed of the fan

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.

Using less energy is the objective so how do we do this? The solution is two-fold for having an efficient running system. One is to reduce the heat gain by insulating the home and adding things to the home such as attic fans. These things help reduce heat gain to the living areas that you want to condition with cool less humid air. The second thing you can do is to purchase a higher efficient system that can modulate or offers staging from a high level for higher demand to lower level for lower demand.

Variable Speed ECM Condenser Fan Motors – The Future

HVAC Manufacturers introduced two-stage compressors and in the future (offered currently in commercial systems) modulating compressors that will run according to the demand based on exactly what you need to condition your space. Since the compressor would stage based on demand they needed a condenser fan motor that would also stage based on demand. Some manufacturers use a standard multi-speed fan motor while others use a ECM fan motor to facilitate a higher speed for the increased demand when the system is calling for higher demand and a lower speed when the system is calling for a lower demand. So when the compressor is running at a higher speed the condenser fan motor will also run at a high speed and when the compressor is running at a lower speed the fan motor will run at a lower speed.

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Variable Speed ECM Condenser Fan Motors

Variable Speed ECM Blower Motors | HVAC Heating & Cooling Systems

ECM Variable Speed Blowers

Variable Speed ECM Blower Motors

An ECM Variable Speed Blower Motor in a squirrel cage blower

Variable Speed ECM Blower Motors - Variable speed blower motors have become increasingly popular in residential air conditioning and heating systems and for good reason; these motors increase efficiency of the systems and offer a whole range of other benefits that help the system and the consumer.

Variable Speed ECM Blower Motors

Variable Speed Blower Motors first offer a higher efficiency for air conditioning systems based on the manufacturers set up of the control with the ECM Variable Speed Motor. Each manufacturer calls it a different thing such as Trane calling it the Comfort R  and Carrier calling it Infinity Control. Despite what the manufacturer calls it helps efficiency with air conditioning by starting the blower slowly and letting it run at a 50% speed for the first few minutes (up to 7 minutes) to remove more humidity. This increases comfort and efficiency by removing more moisture from the air. The lower the humidity in the cooler you will feel so the variable speed blower with this type of control will enhance comfort. Continue reading

Condenser Fan Motor | Air Conditioners & Heat Pumps | HVAC Refrigeration

Condenser Fan Motor

Condenser - Air Conditioner - Heat Pump Fan Motor

Condenser Fan Motor Inside the Condenser

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. Continue reading

Gas Furnace Components 3

Ignition Controls

Gas Furnace Components 3Gas furnace ignition controls vary from furnace manufacturer to furnace manufacturer. Some are proprietary and some are from an engineering company which specializes in gas furnace ignition controls. Honeywell being a major manufacturer of controls for HVAC also makes several gas furnace ignition controls. Gas furnace ignition controls have advanced by leaps and bounds over the last 20 years coming from the norm which was standing pilot ignition all the way to solid state ignition controls which exist today and are safer and more efficient than the gas furnace ignition controls of yesteryear. Aside from a few companies which lag behind in technology for whatever reason to some water heater manufacturers who continue to adhere to the old standing pilot ignition controls the new modern systems offer safety and efficiency in all their gas furnace controls. Honeywell was the pioneer as they are with much of the modern HVAC technology and Lennox and Carrier came in just behind Honeywell with advancements in engineering of gas furnace ignition controls that changed the entire HVAC gas furnace industry.

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