Condensate Drainage Options for Aprilaire Dehumidifiers

Condensate Drainage Options for Aprilaire Dehumidifiers

This article applies to:

Aprilaire 1710 Free Standing Dehumidifier
Aprilaire 1750 Ductable Dehumidifier
Aprilaire 1770 Ductable Dehumidifier

Condensate (water removed from the air) drains via gravity from the rear of all of the Aprilaire dehumidifiers.  We have created this article to eliminate confusion about the different methods for draining condensate.

These dehumidifiers can be drained into a floor drain or sump pit - OR can be hard plumbed into your home's drainage system.  Each unit is shipped  from the factory with a PVC "p-trap".  It is not always necessary to use this trap.  In cases where you are simply draining via gravity into a floor drain, sump pit, or pump  - a simple floor drain kit can be built (we include one in the 1700FS model to make things convenient for our customers) with commonly available plumbing fittings.

When should I use the included "P" trap?"

A).  When you are plumbing your condensate into your homes main waste drain.  Because of its shape, the trap retains a small amount of water in the "bend" of the trap. This water in the trap creates a water seal that prevents sewer gas from passing from the drain pipes back into the home.  This will also prevent any backflow of condensate.

B).  When you are ducting your dehumidifier into your main air handling system - a small amount of negative pressure (vacuum) can be created within the dehumidifier with could cause the unit to drain improperly.  In this case, the trap should be used.

The trap fits into the drain opening in the dehumidifier and can be affixed with PVC cement. 


For simple floor drainage - it's easy to assemble a floor drain kit with some 3/4" ID vinyl hose, a 3/4" SPIG X 1/2" FIPT bushing and a hose fitting with 1/2" threads.  The bushing fits on the drain and barbed hose connection fits onto the tubing.  With this configuration, you can easily drain into a floor drain or a condensate pump.

Most condensate pumps can accept 3/4" vinyl tubing in any available port.  make a diagonal cut in the end of the tubing that inserts into the pump.  Most pumps (like the Little Giant condensate pumps we sell) will use a 3/8" ID tube to pump out water.  This tubing is not included with pump purchase.

Note that in each case, especially where a pump is involved, you will want to raise the dehumidifier up from floor level.  This can be accomplished to some extent by extending the feet.  You could also raise the unit on bricks, cinder blocks, treated lumber, etc.