HVAC Refrigeration Evacuation | Technical Refrigeration - Why is it necessary to evacuate a refrigeration system before charging it with refrigerant? Because all systems are designed to operate without moisture or non-condensable gas in the system. If your air conditioner or heat pump was installed without a proper evacuation the system it will not function as designed and will likely fail prematurely. (more…)
Free Cooling Air Conditioning - I’m looking for a residential high-performance system that uses an air intake damper or a multistage (multi-zone) heating and a cooling system similar to what I found at Economizer Systems and HVAC Control?
Any suggestions? Answer…………… (more…)
Richard - Very nice site!- Dual Two-Stage Split System with a Dual Slab Coil - I have a question; my home was fitted out by the previous owner with a twinned system, and a thermostat (Totaline P374-1900) which was not designed to control discreet, paired units. I confirmed this with Totaline. The result is only one unit runs, and the second unit is never activated. It functions, but not automatically.
York VAV Air Handlers | HVAC Zoning - This York air handling unit serves several VAV boxes and runs on a static pressure control set point determined by a DDC program. This program has a static pressure control setpoint and sends a signal to the variable frequency drive to speed up or slow down the blower to maintain the proper static pressure control setpoint. When the VAV boxes need more air the drive speeds the air handler blower up.
When the VAV boxes need little the drive slows the blower down. The VAV boxes are controlled by a thermostat in their respective zones.
This photo shows the air handler blower compartment. This is how the air handler is opened when the blower needs service or repair. The evaporator coil is on top of the blower which makes this an upflow air handling unit. The supply air ductwork will be above the AHU. Since this air handler is installed in a closet then the ductwork is installed in the ceiling and makes this an ideal installation for AC since cool air falls. (more…)
Lennox Versus York Air Conditioners - Here is a Lennox and York comparison for their premium model air conditioner as requested by a reader of the site. Just off the top of my head, both systems are good systems. I would say Lennox had a slight advantage but the first-hand experience in the field gives most HVAC technicians the opinion that Lennox is over-engineered. (more…)
Refrigerant Pressure Temperature Chart | HVAC Refrigeration - This page offers a temperature-pressure relationship chart for use in working with HVAC Systems that use R-410A, R-22, and R-134A. Additional refrigeration information and resources are located below the chart. For more information and comprehensive articles on HVAC Refrigeration see our Refrigeration Category. (more…)
Guides for Residential HVAC Technicians - There are many HVAC technical guides and manuals available to help HVAC technicians hone their skills on the job and become even better and more knowledgeable HVAC technicians. We can all use improvements in everything we do in life whether it is professionally or personally and always remember one can never know everything. (more…)
Learning the Basics of HVAC - To understand air conditioning and heat pump applications you will need to study refrigeration. Both air conditioners and heat pumps use refrigeration to move heat. Air conditioners move heat outside in the summertime using the process of refrigeration. Furthermore, heat pumps move heat in both directions (to the inside in the winter and to the outside in the summer) using the principles of refrigeration. (more…)
