Haier AD12MS1ERA Operating Manual And Instructions page 26

Installation Procedure
Drain Piping
Good piping
For unit without water pump
Unit model
AD12MS1ERA AD12MS1ERA(D)
AD18MS1ERA AD18MS1ERA(D)
AD24MS2ERA AD24MS2ERA(D)
AD28MS2ERA(S) AD28MS2ERA(S)(D)
AD24MS1ERA AD24MS1ERA(D)
AD28NS1ERA(S) AD36NS1ERA(S)
AD48NS1ERA(S)
Improper piping
The size of drain opening
21mm
15.5mm
33mm
For unit with water pump
Drain Pipe