Mini Split Condensate Drain Line Installation (How To Guide)

One basic thing you need when you have a mini-split AC is a way to drain condensate. This happens through a mini-split drain line connection.

In this guide, we will go over mini split AC installation, condensate, and how to deal with it.

How To Install A Mini Split Condensate Drain Line (DIY Installation)

Most mini-split units need a gravity-type drain instead of various units (floor mount, ceiling, or cassette) that use a condensate pump or give options for field-supplied condensate pumps.

Supplies And Materials Needed

  • 5/8″ inner diameter vinyl drain tube
  • Condensate traps
  • Condensate pump (if needed)

DIY Step By Step Guide

  1. Firstly, figure out where your condensation drain will be installed before starting.
  2. Gravity drains usually need a pitch range of about ¼ inch per foot without any piping dips.
  3. Furthermore, condensate traps may be needed for your gravity type drain based on your drain location. Though if you use field installed condensate pump, reference its lift ability always to make sure not to exceed the drain height.
  4. If a drain pump is required, put it in a place where you will not hear at night.
  5. The best way to remove your mini-split condensate is via a 5/8″ inner diameter vinyl drain tube, and it is the standard method for almost all floor- and wall-mounted indoor units.
  6. When you use a flexible vinyl tube for condensate expulsion, ensure that the tube does not kink since it will prevent water from escaping and can cause water to overflow into the indoor unit.
  7. You can also use braided tubing rather than the typical clear tubing, as it will significantly reduce the kink chances of your tubing.
  8. The drain line must also be sloped downward the whole way to prevent any backups.
  9. For a similar reason, it is critical to note that the hole via which the drain line run be ¼” to ½” low outside than inside. Doing so will help keep your drain line angled for the proper drainage.
  10. A common callback source is condensate leakage, as the condensation temperature can be below or at the dew point of air temperature.
  11. Insulate the condensate line to prevent any ‘sweating’ during the cold season, and a ‘heat tape’ for winters to avoid any freezing.
Where Do You Put A Mini Split Drain

Mitsubishi Mini Split Drain Line Installation

Follow these steps for your Mitsubishi mini-split drain hose installation:

  1. Place drain hose right below your refrigerant piping
  2. Ensure that the drain hose is not bent or crowded
  3. When applying the tape, do not pull the hose
  4. When the drain hose passes your room, ensure that you wrap it via insulation material

Also, make sure that you do not damage your refrigerant pipe cover while attaching it back through screws.

Daikin Mini Split Drain Line Installation

To set up your Daikin condensate drain, follow these steps:

  1. The drainpipe diameter must be equal to or greater than the diameter of your connecting pipe
  2. Keep drainpipe sloping downwards and short
  3. If you cannot set your drain hose suitably on a slope, get a drain raising piping
  4. Use a metal clamp to tighten your drain hose
  5. Insert drain hose in the drain sockets up to tape
  6. Tighten the clamp until the screw head is lower than 3/16″ from the hose
  7. Wrap sealing pad over metal clamp and then drain the hose for insulation
What Is A Condensate Drain Line

Where Do You Put A Mini Split Drain?

Mini-splits typically drain to the closest greywater plumbing pipe. The mini-split drain outlet is generally located at your nearest greywater plumbing pipe, which is employed to discharge the basin wastewater.

Your mini-split must not drain to either the rainwater or blackwater plumbing pipe. This is because the greywater plumbing pipe is exclusively to discharge wastewater like basins and showers. It does not have a strong smell, which might travel back to your mini-split and turn your room into a smelly mess.

On the flip side, you must never put a drainpipe to soil water or blackwater plumbing pipe responsible for toilet bowl’s wastewater. Additionally, it is not suggested that you discharge condensate water to the rainwater downpipe since water flow may be too strong that your condensate water cannot properly discharge and backflow to the indoor unit.

What Is A Condensate Drain Line?

The condensate drain line runs through your mini split air conditioning system and leads outside. Condensate in a mini-split is the water droplets formed via condensation.

Think of when you had an ice-cold drink in hand and why your mom always asked you to use a coaster on the furniture. In both cases, water droplets would be created. A similar process happens in your mini-split; warm air passes through the refrigerant-filled cooling coil.

Moisture in warm air condenses over the cooling coil and creates condensate or water droplets. Your mini-split condensate line will keep moisture from building up inside the home since moisture is a foe of a functioning appliance as it leads to mold spores, corrosion, and mildew.

How Do Mini-Split AC Units Drain Water?

Mini-split employs a mini-split drain line to remove condensate water through gravity flow. The highest point of the drainpipe is the inlet, where the condensate water flows towards the outlet. Here are various ways to drain your mini-split:

Exposed Drain

Various homes, mainly landed houses, discharge condensate water simply outside the home since they own that property and do not mind it.

The installer creates a hole through the wall for refrigerant and drainpipes since your indoor unit must connect to the outdoor unit.

Concealed Drain

Often, it is not a great idea to let condensate water simply drip outside your house. Therefore, many individuals conceal the mini-split drain line inside the floor and wall, run to the closest floor trap, and look clean.

Aid Of A Drain Pump

Sometimes, a part of the drainpipe must be installed higher than the drainpipe inlet; therefore, a drain pump is required to assist with the water flow. The drain pump must be installed lower than your mini-split to push the condensate water against the drain pump inlet, giving adequate positive suction pressure for the drain pump to work efficiently.

People Also Ask (FAQ)

Below are frequently asked questions on mini-split condensate drain line installation.

How much condensate does a mini-split produce?

A mini-split air conditioning unit typically drains the water, which was once the humidity, out of your house. On an average basis, you can expect around 5-20 gallons of condensate in a day.

Does a mini-split need a condensate trap?

Mostly, a mini-split does not need a condensate trap. A floor mount and wall mount mini split does not require a condensate trap for proper drainage. However, a ducted or ceiling concealed mini split requires a condensate trap to drain appropriately.

Do mini-splits drain need insulation?

The condensate water that the mini-splits produce is cold. Therefore, the drainpipe insulation is critical to prevent condensation.

Do mini-splits condensate in heat mode?

No, they do not. Your mini split’s indoor unit will not create condensate water while operating in heat mode.


Now you know of your mini-split condensate drain options and the advantages of each. Consider the preferences for your home since they will help you decide the style of condensate removal that will truly serve your needs.

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.