How long should hot gas defrost be?

Open the hot gas solenoid only long enough to clear coil (8-10 minutes). Install a separate hot gas solenoid and defrost regulator for pre and post-heating of the pan loop.

How to size refrigerant lines?

In order to determine the equivalent footage, add the actual length of the piping run and the equivalent footage assigned for each particular fitting. Plot the intersection of the horizontal BTUH line with the vertical equivalent footage line. The area in which the plotted point falls in the recommended line size.

How many types of defrost systems are there?

There are two major methods of defrosting. These include: Automatic defrost and Manual defrost. In each, the idea is to prevent the build-up of ice crystals inside the refrigerator.

When should you trap refrigerant lines?

If the condenser is as much as 8 or 10 ft above the compressor, provisions should be made to trap the oil and refrigerant that might otherwise condense in the compressor heads when the compressors are stopped.

What is more effective hot gas defrost or electric defrost?

Even not being largely applied as the electric defrost, the hot gas defrost in a lot more efficient, since the heat source flow through all coil circuit, allowing a more effective heat exchange with the formed ice. During the defrost procedures, the heaters are activated to melt the ice on the coil.

How does hot gas defrost work?

Concisely, the hot gas defrost method uses the naturally occurring high-temperature refrigerant vapor from the discharge side of the compressor to warm the evaporator coil and melt the ice accumulated on it.

How does line length affect refrigerant charge?

The factory charge will handle up to 15 feet of 3/8-inch line. This means you must add refrigerant for 85 feet of 3/8-inch line. According to the chart (Figure 2), you would have to add 3 pounds and 1 ounce to this system to get it to work properly. This means you have to overcharge the system by about 44 percent.

What is cool gas defrost?

Cool gas defrost systems use cool gas(vapor) from the top of the receiver instead of hot gas(discharge). The defrost valve, which is piped into the top of the receiver, energizes sending cool gas through the suction line to the cases. There is a bypass with a check valve around the txv.

What are methods of defrosting?

There are three safe ways to thaw food: in the refrigerator, in cold water, and in the microwave.

What is the purpose of a P trap on the suction line before the compressor?

When the compressor is running, the p-trap acts as a turbulator to bring oil droplets up the elevated discharge line. Therefore, having said traps is simply good practice. It helps ensure the longevity and functionality of your refrigeration equipment.

Why is a double suction riser used?

The smaller pipe is selected to maintain capacity and velocity at minimum load. The double riser works because on low load, as the suction volume is reduced, so is the velocity in a certain size suction pipe.