What does a head pressure controller do?

The flooded head pressure control valve maintains head pressure by backing up liquid refrigerant into the condenser, and in doing so reduces condenser capacity.

Why do we need head pressure control?

Head pressure control is required because refrigeration equipment unlike air conditioning equipment must be able to run in very low ambient outdoor temperatures. There are various ways of falsely loading the condenser to raise high-side pressure to of the most common are: Fan cycling controls. Fan Cycling.

How does floating head pressure control work?

So what is floating head pressure? In this system, the process uses ambient temperature to allow the pressure to be regulated. It is sometimes called an air-cooled system because of this. Instead of the valve system being used, the pressure is allowed to ‘float’, automatically following outside air temperature.

What is chiller head pressure control?

As the chiller loads modulate, a refrigerant head pressure controller modulates a two-way automatic valve on the condenser water side. Differential pressure transmitters sense the change in water pressure and control the condenser water pumps in the same manner as the chilled water pumps.

How do you control head pressure?

Fan cycling is the easiest and cheapest way to maintain a minimum head pressure. By using a close on rise pressure control we can successfully cycle the condenser fan on or off to maintain head pressure. Fan cycling controls can be adjustable or non-adjustable.

How does head pressure work?

It is a measurement of the height difference between the fluid being moved and the discharge point. If head is the vertical measurement between where a fluid is and where you want it to be, then head pressure is simply the amount of pressure you need to get the job done. Read a full explanation of head pressure here.

What is floating suction pressure?

Floating suction or floating suction pressure control is an Energy Management strategy utilizing electronic rack controllers to automatically adjust the refrigeration system suction pressure setpoint based upon actual temperatures at the cases or walk-ins.

What is head pressure in a refrigeration system?

Discharge pressure (also called high side pressure or head pressure) is the pressure generated on the output side of a gas compressor in a refrigeration or air conditioning system. An extremely high discharge pressure coupled with an extremely low suction pressure is an indicator of a refrigerant restriction.

What does pressure in the head mean?

Most conditions that result in head pressure aren’t cause for alarm. Common ones include tension headaches, conditions that affect the sinuses, and ear infections. Abnormal or severe head pressure is sometimes a sign of a serious medical condition, such as a brain tumor or aneurysm.

What is a head pressure in HVAC?

What is the formula for head pressure?

hp—the pressure head = u/γw—the fluid pressure divided by the unit weight of the fluid. ht—the total head = he + h.

How does a head pressure control valve work?

Energy Savings When a system’s head pressure is controlled using a flooded head pressure control valve, the condenser fan motor runs at 100% fan speed all of the time. When head pressure is controlled using an EC motor and the motor speed is varied according to operating conditions, this results in lower energy consumption of the motor.

How long should a head pressure control be on?

R407A R448A R407C R404A R507220 238 245 255 265 Table 2 – Ambient Fan Cycling Thermostat Cut-Out Settings Table 3 – Pressure Fan Cycling Cut-In Control Settings FAN CYCLING CONTROLS SHOULD BE SET TO MAINTAIN A MINIMUM OF (5) FIVE MINUTES ON AND (5) MINUTES OFF. SHORT CYCLING FANS CAN RESULT IN PREMATURE FAILURE OF FAN BLADES AND/OR FAN MOTORS

When to use variable speed head pressure control?

VARIABLE SPEED MOTOR CONTROL ON HEADER FAN (used with fan cycling ) If additional head pressure control is required beyond the last step of fan cycling, variable fan motor speed methods may be used. A varying motor speed may be accom- plished using a modulating temperature or modulating pressure control.

When is head pressure controlled using an EC motor?

When head pressure is controlled using an EC motor and the motor speed is varied according to operating conditions, this results in lower energy consumption of the motor. The amount of energy to be saved depends on; ambient condi- tions, system operation conditions and head pressure set point.