Helpful Guide on how to install AC drainage for condensates

Having an air conditioning unit in your home is a huge relieve in a vast number of countries. Why?, because it saves our a***s a lot from extreme temperatures. A well-constructed air conditioning system is marvelous, if not used excessively; it balances the temperature of your homes, helps to replenish strength to refresh the human body for whatever exercise or deed you’re to do next. Now there are experts who are trained to install Air conditioning units, but atimes they may need a plumber to complement them to ensure their work is done completely and perfectly; even if it’s a minimal job.

air conditioning

One of the jobs to be done is providing a condensate drainage line for Air conditioning units; for some of us who have little understanding to what these are, a condensate drainage line is structured pipe linking from the A.C unit to external environment. The aim of the condensate discharge line is to collect moisture gathered by evaporator coil as moisture passes through it. Basically, the coil removes humidity from the air and converts it into moisture; the water drains into the condensate drain pan and then enters the drain line to travel down the drain pipe to be deposited outside the housing structure. In simple terms; it releases used excess water to the outer environment.

The condensate drainage line is one of the most important yet simple parts of an HVAC/ AC system, and that is more reason why you should understand how to have them fixed or installed on your own, paying for such small jobs when it can be done by your hands isn’t exactly a good look so a simple guide will be given below to share relevant details on what you need to know and how it needs to be done.


Installing an AC drainage line can be of two forms that depend on its environment of use; these forms include;

  1. A domestic HVAC drainage
  2. An industrial HVAC drainage

The both mentioned above are quite similar in function and partly in structure; yet they are also quite distinct. Domestic condensate drainage is primarily one pipe connected to whatever HVAC unit you have in your home and running out to the outdoors.

However, an industrial HVAC drainage line is a pattern of drainage lines all connected to individual AC units and also linked together to lead down one drainage line which also leads outdoors. The industrial system can be used both in domestic and industrial environments that have multiple AC units to link to and if you’re willing to bear the expense in terms of cost.

Asides from connecting various pipes from various AC units to one discharge and connecting one pipe to one AC unit; the rest of the installation processes are basically the same.


Examine AC unit;

Air conditioning units come in various forms, sizes and structures; ideally enough, you should examine the outer components of the unit preferably with the use of a manual or guide to identify the discharge outlet for the condensates. The examination should be done carefully. Typically the outlet is situated at the overflow/ drain pan

NB; to ensure proper safety against hazards, if HVAC units were previously installed or connected to a power source, make sure AC unit is disconnected before examining.

Highlight route for drainage line;

Typically, decisions on choosing the route of condensate drainages are most likely already made on the structural design. The structural drawing might indicate the added detail of how the discharge pipe will route to best suit its environment and cause less obstructions. However if not, as a DIYer or plumber, it’s best to examine the house or the station where the AC is placed to look for the best possible route you can pass the drainage through. Here are a few tips on what you should consider;

  • Make sure your pipes are to be passed as discretely as possible i.e. avoid having them being placed in public locations. Having them hidden in walls tend to help.
  • Avoid having them places at spots where they may seem like obstructions.
  • You should consider your final location each time you discover a route you can utilize i.e. if you are considering an open drainage or a garden as a final location to deposit the water, when highlighting your routes, ensure the difficulty and distance of running them from the AC station to that final location isn’t needlessly excessive. So keep your final points as close by as possible and your pipe runnings not too far from them.
  • Consider the placements of traps and vents; this can be slightly tricky but ensure your discharge line passes an area spacious enough to accommodate a trap and a vent.

Select appropriate tools and materials;

Selecting an appropriate tool for the job is vital, as it comes from a mindset of having an idea of what you’re about to embark on and preparing for it. The tools are to be carefully selected and made available for immediate use before starting the task; if you have no idea on what materials you might need, a list will be highlighted below however; the choices of pipes to be used will depend on your personal preference or factors based on where you’re placing the pipes

Materials Tools
Drain pipe Measuring tape
PVC glue and primer Hacksaw
Pipe materials and bends Drill
Flux solder (optional) Jigsaw (optional)
Wall clips (optional) Sandpaper (optional)
Chisel (optional)
Mallet (optional)


PVC pipes, PEX pipes and CPVC pipes are ideal choices for air conditioning drainage lines however protection against ultra violet rays has to be provided, which will require a slight rise in cost. Copper and stainless steel are also good candidates but with regards to the price difference, sticking CPVC or PEX is suggested.

Carve out path or create channel for pipe (if required);

After highlighting the route you like your pipes to go through, a common question is asked on whether to have your pipes embedded in a wall or have them run on the surface. Both have their benefits but when considering an AC condensate drainage alone; we’d rather have our clients run them on the wall or have them externally placed due to easy access for maintenance and repairs. This can be done by just having clips drilled to the wall and pipes run through them.

However if by personal preference you’d like to have them in the walls, the use of a chisel, mallet or a  hammer drill will come into play if you’re dealing with concrete or wooden walls. For the length you’re going to have your pipes running for, you’d have to chisel and open up a wall path all through to its final point.

Inevitably, there will have to be a point where the pipe goes out to the external environment i.e. a hole or an opening of sort. This opening should be spotted and created with use of a drill. To create a larger hole, you can outline the size of the hole on that point on the wall, drill about 6 to 8 points on the circumference and punch the hole with a chisel and mallet.

Connect pipes and run your drainage line;

To connect and run a pipe for condensate discharge, the following steps should be taken;

  • Measure the size of the condensate outlet; the size of the condensate outlet should be identified and measured preferably with the use of a tape, the sizes of the outlets are typically ½ inches although they do vary in some instances.
  • Utilize a socket to connect outlet to the pipe; a threaded male socket can be used (with a Teflon tape) if the condensate outlet is threaded internally or a threaded female socket if condensate outlet is threaded externally; if outlet is not threaded at all, a plane pipe coupling of similar size can be inserted to the outlet, this done with the use of PVC glue or primers and then connected with a short length of drainage pipe before connecting to the main discharge line.
  • Create a trap adequate enough to prevent the entry of suction of air but allows the flow of moisture. After first or second turning of the drainage line (with the use of pipe bends), a trap should be created at the specified dimensions in the diagram below; having a vent too shallow would allow for rapid escape or drying of moisture and have a trap too deep would likely return moisture from draining pipes back to the AC unit which ofcourse is a bad sign. So there has to be balance in depth with a vent pipe provided.
  • Run the final discharge line down to the deposit point; if pipes are run vertically, gravity will obviously sort out the movement of the condensate. However if run horizontally, slopes are to be applied to the drainage with a standard of 1 cm difference in depth per 1 meter to its final point.

Here is a video highlighting the steps if further explanations is required for running a domestic condensate drain;