Category Archives: Refrigeration

Replace Air Conditioner Compressor | HVAC Refrigeration

Replace Air Conditioner Compressor Decision | HVAC Refrigeration Question

Replace Air Conditioner Compressor | HVAC Refrigeration – Question – Richard – I am an HVAC technician and have read all of your articles on refrigeration and compressors. Great information and it has helped to hone my skills and offer better service for my customers. Thanks! I was wondering what your experience is with replacing compressors. How do you arrive at the decision to replace a compressor technically speaking of course? I look forward to reading your answer. Brett

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Air Conditioner Condensing Unit Frozen | HVAC Troubleshooting

Air Conditioner Condensing Unit Frozen | HVAC Troubleshooting

Air Conditioner Condensing Unit Frozen | HVAC Troubleshooting

Old Condenser

Richard – Early last month we turned our air conditioner on and it worked fine for a few days. Then I noticed it was getting a little warm in the house so I went around and checked the Air Conditioner. Of course I checked the thermostat first and then the air filter. I went up into the attic to look at the air handler. I did not notice anything out of the ordinary that I am not used to seeing but I am not an expert. Then I went out to the the condensing unit on the back patio and I saw some ice inside the condensing unit. The compressor and the all the pipes connecting to the compressor were a block of ice and frozen solid. I turned everything off and called the HVAC contractor I am used to dealing with. They told me they would send someone out to take care of it. A few hours after making the call I got a call from the technician. He told me there probably very little he could do for me now as we would have to let the ice melt before he could properly troubleshoot the problem. We agreed for him to come the next morning to check it out. He told us to leave the air handler blower fan on but make sure the condenser was off. He told me to go to the breaker box and turn the condensing unit off and use the thermostat for Fan Only operation. We did exactly as he said.

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Delay Timers and the Air Conditioner Condenser | HVAC Control

Delay Timers and the Air Conditioner Condenser - Unit with the top off - condenser fan motorDelay Timers and the Air Conditioner Condenser – Heat Pump Condenser

Air Conditioners are big HVAC refrigerators. Air Conditioners and Heat Pumps use the HVAC refrigeration cycle to transfer heat from a place where it is not wanted (inside absorbing heat with the evaporator coil) to a place that makes no difference (outside using the condensing unit)(in the cooling cycle). The heart of any HVAC air conditioning, heat pump, or refrigeration system is the compressor which pumps the refrigerant through the HVAC air conditioning system. When the refrigerant leaves the compressor it is compressed and therefore a higher pressure than it was before it entered the compressor inside the condensing unit. This pressure remains constant (give or take under certain conditions) until it passes through the metering device where the pressure and temperature are reduced. This low pressure remains constant (again give or take under certain conditions) until it again reaches the compressor inside the condensing unit and is compressed again.

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Copper Versus Aluminum Coils – Condensers and Evaporators

Copper Versus Aluminum Coils - Condensers and Evaporators

Copper coils covered with aluminum fins

Copper Versus Aluminum Coils – Condensers and Evaporators – Some manufacturers are starting to transition from copper coils to aluminum coils for both condensers and evaporator coils for various reasons. When making a decision to purchase a new system you need to inform yourself about the pros and cons of purchasing a system with aluminum coils or copper coils. Traditionally, copper was the chief choice to use to manufacture evaporator coils and condenser coils because of heat transfer rate, cost, pliability (easy to bend and swage), and because copper line sets are used to join split systems. The cost of copper has skyrocketed and that was a game changer. Many manufacturers have started looking at aluminum because the cost of aluminum is cheaper than copper and aluminum has some of the same benefits of the above mentioned properties that copper has. 

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Compressor Overheating Troubleshooting | Diagnosis and Repair

Compressor Overheating Troubleshooting - Diagnosis and Repair

Compressor Overheating Troubleshooting

Compressor Overheating Troubleshooting - There are some problems with an air conditioner or heat pump system that can be avoided with proper maintenance. Other problems result in a mechanical or electrical problem with the systems that needs to be resolved. Compressor overheating is a serious issue that can cause serious problems with your air conditioner or heat pump system. A compressor that overheats can still operate and provide effective cooling or heating but if the temperature inside the compressor rises too much then the oil in the compressor can break down and reduce the lubrication and cooling effect the oil has inside the compressor. This leads to possible mechanical failure and other problems that will occur to the compressor and in the refrigeration system that results from compressor overheating. When the oil becomes overheated it changes chemically and other a lack of lubricating and cooling effects it becomes like an acid. This eats away at the windings and will cause compressor failure.

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