Liquid lines generally are insulated. They are warm to hot (110°F (43.3°C) for air-cooled). If liquid lines pass through a space that is warmer than the refrigerant (i.e. the roof of a building at roof level), or if they could be considered hot enough to pose a safety risk, then insulation should be added.

Why is the liquid line not insulated?

There is no need to insulate the smaller, warmer copper pipe, often called the liquid line, because not insulating this line allows it to shed heat which is exactly what you are trying to do with an AC system.

What happens if the suction line is not insulated?

If the return line is not insulated, the refrigerant returning from evaporator to the compressor will absorb some heat, more heat than it had at the outlet of the evaporator. This extra heat will also be present in the compressed refrigerant going to the condenser, downstream of the compressor.

Do you insulate the liquid line on a heat pump?

It’s not necessary to insulate the liquid line coming off the indoor coil. The freezing effect you’re referring to, will take place at the heat pump outside. When this takes place, the heat pump will switch to a defrost mode to get rid of the frost. This is normal operation for a heat pump.

Is the discharge line insulated?

Discharge lines are generally uninsulated. They may be very hot, in excess of 150°F (66°C), so insulation may be warranted as a safety consideration, or if the heat loss from the discharge gas line would be considered objectionable to the space.

What happens if you insulate liquid line?

Re: Liquid Line Insulation

if it is metered from the outdoor unit, on cooling mode the liquid line will contain low temperature saturated refrigerant that will condensate, and will start to boil off prematurely before the evaporator, resulting in a loss of performance and energy.

Which refrigerant line is insulated?

suction line

Refrigerant Lines
The larger line typically carries a cool gas and is insulated. This is commonly referred to as the suction line, but it is also called the return line or vapor line. The smaller uninsulated line typically carries a warm liquid.

What is the purpose of insulation on the suction line?

Insulating the suction line is done to prevent condensate from developing and dripping off. This condensate drip can cause water damage to the material under it or cause a slip hazard for people walking below it.

Why should some refrigerant lines be insulated?

Without insulation around the low-pressure refrigerant line, condensation may form. The low-pressure refrigerant line will develop condensation that can cause moisture damage. To protect against condensation, the low-pressure refrigerant should be insulated.

Does expansion valve need to be insulated?

Re: TXV Expansion valve insulation

Hey Gene Jim is correct, the expansion valve bulb needs to be insulated because it is operating the valve to maintain the superheat of the evaporator.

Should AC lines be cold?

The Copper Pipe (Suction Line) should be sweating and cold to the touch during a hot day. If it is not cold, your compressor could be off (bad capacitor/ hard start kit) or low on Refrigerant.

Can you run refrigerant lines in a wall?

Mini split refrigerant lines can be run in walls. It is a common practice to hide the refrigerant pipes of mini splits in dry walls for aesthetic purposes. Apart from being more difficult to repair, concealing the refrigerant lines in walls have no impact on the performance of the mini splits.

Should both AC pipes be cold?

There are two pipes from the condensing unit (outdoors) to the evaporator (indoors). One should be full of liquid refrigerant on its way to the expansion valve, the other should be cooler, returning to the compressor suction.

Is the liquid line the high side?

The high side, or discharge line, will be the line connected to the compressor from the bottom or lower position. It will not be wrapped in insulation and will be warm to the touch. This is where freon exits the compressor as a liquid.

Why is my suction line sweating?

If an uninsulated suction line is below the Outdoor Ambient Temp (OAT) dew point it will condense moisture. Of course, the OAT dew point can vary a great deal; just ignore the sweating issue. (Where is the insulation?) Forget about a sweating suction line, it is NOT an indication of an incorrect charged system.

Why is my AC liquid line cold?

Chances are, your indoor unit’s evaporator coil is frozen solid and cold liquid refrigerant is flowing to the outside unit through the refrigerant line (which is why it’s covered in ice). DO THIS RIGHT NOW: Turn off your AC and turn the fan setting to “ON.”

Why is my suction line not getting cold?

The Copper Pipe (Suction Line) should be sweating and cold to the touch during a hot day. If it is not cold, your compressor could be off (bad capacitor/ hard start kit) or low on Refrigerant. Your Breaker is Tripped. Be Careful because this usually indicates a problem with the compressor or wiring.

How do I stop my AC lines from sweating?

Wrapping your AC ductwork is an effective way to prevent condensation. Duct wrap has a foam insulation inner layer and a foil outer layer. Cleanly wrap it around the AC duct and fasten with duct tape near the joints.

Should I insulate air conditioner coolant pipes?

Most air conditioning systems have a low-pressure and a high-pressure refrigerant line. Of these two lines, you typically only need to insulate the former. Insulating the high-pressure refrigerant will protect against condensation.

Should AC line be sweating?

Condensation is normal for properly running air conditioning systems. Excess condensation, like sweating ducts and drips from outside the unit cabinet indicates a problem with your unit and points to an HVAC system issue that requires emergency HVAC repair service.