Compressor Rebuild | HVAC Heating and Cooling Refrigeration

Compressor Rebuild – This freshly rebuilt reciprocating compressor is destined for a large commercial chiller. Chillers chill water for air conditioning. Compressors compress refrigerant vapor and pump the compressed refrigerant to the condenser to be condensed into a liquid. The compressor provides compression which is an integral part of the refrigeration process. The old compressor was condemned for electrical burn out. The windings in the old one burned up and caused the circuit breaker to trip. (more…)

HVAC Centrifugal Compressors | HVAC Refrigeration

HVAC Centrifugal Compressors - Centrifugal compressors are used in many applications including pipeline transport of natural gas along with many other related applications including vapor compression refrigeration. These compressors have different operating limitations than the reciprocating compressor, the scroll compressor, and the rotary compressor. They an operating range where it operates efficiently however outside of this range, either the over or under that operating range, is basically useless. Other issues make them not ideal for use in certain applications because of the operating range issues. (more…)

About Chilled Water Systems | HVAC Hydronics

About Chilled Water Systems | HVAC Hydronics

About Chilled Water Systems

About Chilled Water Systems

Old York Chiller

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.


Chilled Water Pipe Vibration Isolators | HVAC Piping

Chilled Water Pipe Vibration IsolatorsChilled Water Pipe Vibration Isolators

Chilled Water Pipe Vibration Isolators - Vibration isolators protect the chilled water piping from receiving vibrations transmitted through the piping when the chillers are running. The vibrations can create problems not only for the chilled water piping but also for the buildings structure. The vibration isolators reduce or eliminate the vibrations that can be transmitted by the chillers. Other equipment normally specified with vibration isolators includes air handlers, pumps, condensing units, generators and most types of equipment with motors. Not only are vibration isolators required in the piping but vibration elimination springs or spring isolators are required are required on chillers, pumps, air handlers, and the other types of equipment named above which can produce vibrations when running. Vibration isolators are usually rated according to the static deflection the vibration isolator provides for the equipment. HVAC piping whether it is for hot water or chilled water usually is also specified with springs in the pipe hangers to avoid further issues that can be caused by vibration. Depending on the location vibration isolators will also be rated for seismic activity with further specifications calling for seismic restraints on the equipment and associated piping. (more…)

Crankcase Heaters and Compressors | HVAC Refrigeration


Crankcase Heaters and Compressors | HVAC Refrigeration . Hello, I have a question about crankcase heaters. I am aware that they keep the refrigerant from saturating in the compressor when not running. However, if the refrigerant is R-22, it becomes saturated at approximately 40 degrees. We know the a/c is only operating in warm ambient temperatures. When it is off for the evening hours & the ambient temps stay above 40 degrees, why would one need to have a crank case heater? Why do we need it on during this temperature range, or are crankcase heaters designed to be activated only during the colder months? Also, if one installs unregulated crank case heaters (always operating), can this be a negative factor for the compressor life? (more…)


DDC Controlled Chilled Water Actuator | HVAC Automation

DDC Controlled Chilled Water Actuator

DDC Controlled Chilled Water Actuator

DDC Controlled Chilled Water Actuator | HVAC Automation. This chilled water actuator is attached to a valve which supplies chilled water to the air handling unit. The air handling has a chilled water coil. The actuator modulates the valve based on a set point inside the DDC program. If the program has trim and respond capabilities the set point will rise up and down based on demand. Demand from the VAV boxes or the HVAC zones. Most DDC controlled actuators work off of a DC volt or current signal. (more…)

HVAC 3R NEMA Rated Control Panels | DDC Installation

HVAC 3R NEMA Rated Control Panels | DDC InstallationHVAC 3R NEMA Rated Control Panels

HVAC 3R NEMA Rated Control Panels - These control panels offer resistance to inclement weather. They house the DDC controllers for two small chillers and two air handlers. The chillers provide chilled water for air conditioning to the air handlers. The controllers offer energy management for the air conditioning system. The controllers were mounted outside for a few reasons. The main reason was because this location was closest to the HVAC equipment which provides air conditioning to the building. The secondary reason was because there was no safe or ideal location to install these panels inside the building. (more…)

Large Condenser Pump for a Chilled Water System

Large Condenser Pump for a Chilled Water SystemLarge Condenser Pump for a Chilled Water System

This large HVAC condenser pump serves a new chiller located in a data center. This pump pumps condenser water through the condenser chiller barrel and to a cooling to reject the heat absorbed in the chillers evaporator barrel. The pump works to move the water from the chiller to the cooling and then back through the chiller again. The water is diluted with a glycol solution to prevent freezing in the winter time when the chiller needs to run at low ambient temperatures. (more…)

Old McQuay Chiller Control Panel | Electro-Mechanical Controls

Old McQuay Chiller Control Panel – Electro-Mechanical ControlsOld McQuay Chiller Control Panel

This panel is part of the controls for an older McQuay chiller. New chillers whether they be McQuay, Trane, York, or Carrier chillers still require these types of controls in them to make them work. This part of this electro-mechanical control panel consists of contactors and switches (both manual and automatic) for electro-mechanical control of this chiller. To the right is the main power which feeds the unit with three phase main power. This power is first fed into a manual disconnect switch so that power can be secured to the unit if maintenance or repair is necessary. from there, the power is split between three separate loads. The first load the main power supplies is the compressors. Before the main three phase power arrives at the compressor contactors it goes through additional manual switches so the the compressor circuits can be isolated if necessary. The compressors have overload protection built into the compressors. The second load to which main three phase power serves is the fan contactors. (more…)