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HVACR316 - Piping

Condensation RemovalRefrigerant Traps

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Condensation Removal

• While operating in the cool mode, the air conditioning system will remove moisture from the conditioned air while lowing the air’s temperature. The moisture from the air must be removed safely from the structure. This moisture is called condensate.

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Condensation Removal

• To prevent water damage, a condensate drain line must be run to carry this condensation away. A number of factors must be considered when laying out the condensate piping for a system, including:

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Condensation Removal

• Drain line size• Drain line material• Pitching of the line• Traps • Auxiliary drain pans• Condensate pumps• Safety float switches

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Condensation Removal

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Condensation Removal

• An air conditioner in a climate with average humidity will collect about 3 pints of condensate per hour of operation for each ton of air conditioning. A 3 ton system would condense about 9 pints of condensate per hour of operation.

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Condensation Removal

• If the unit is near a drain that is below the drain pan, simply pipe the condensate to the drain. A trap in the drain line will hold some water and keep air from pulling into the unit from the termination point of the drain.

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Condensation Removal

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Condensation Removal

• The drain may terminate in an area where foreign particles may be pulled into the drain pan; the trap will prevent this. If there is no drain close to the unit, the condensate must be drained or pumped to another location.

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Condensation Removal

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Condensation Removal

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Condensation Removal

• All domestic refrigerators are low temperature appliances, and frost accumulates on the evaporator.

• When defrost occurs, something must be done with the water. The compressor and condenser section of the refrigerator are used to evaporate this water.

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Condensation Removal

• The heat available at the compressor discharge line can be used to evaporate the water when direct contact is made. Many units are designed so that the discharge line is passed through the pan that collects the defrost water.

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Condensation Removal

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Condensation Removal

• When the refrigeration unit has a forced draft condenser, warm air from the condenser may be forced over a collection pan of water for the purpose of evaporation.

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Condensation Removal

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Condensation Removal

• The defrost water collection pan in the bottom of the unit is a place where lint and dirt may collect. This pan can and should be removed occasionally and cleaned, or it may become unsanitary.

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Refrigerant Traps

• Traps in condensate lines help prevent air from flowing up through the drain line, thereby preventing the condensate from draining properly.

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Refrigerant Traps

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Refrigerant Traps

• The condensate drain trap functions in the same manner as the trap under a bathroom sink, which prevents waste fumes from entering the home. A trap is not required on all air conditioning systems. If the refrigerant coil is located downstream of the blower, meaning that air is being pushed through the coil, a trap is not needed.

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Refrigerant Traps

• In this case, the pressure at the inlet of the drain line is at a higher pressure than at the outlet and the condensate will drain properly, However, if the blower is downstream of the coil, a trap must be used.

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Refrigerant Traps

• In this case, air is being pulled through the coil and also through the drain line. This causes the pressure at the inlet of the drain line to be lower than the pressure at the outlet, thereby pulling air through the line in the direction opposite to the direction of the condensate flow.

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Refrigerant Traps

• If the drain line is under a negative pressure and no trap is installed in the line, the condensate will accumulate in the pan and eventually cause an overflow, which can lead to water damage.