Reverse Osmosis Drain on Single Basin Sink

[TX-Tim]

Question,

My sink is single basin with a garbage disposal. I am looking to install a reverse osmosis system. My options for the RO drain is a drain saddle on the neck of the disposal outlet or an adapter on the dishwasher drain line.

Which is the better of the two options or is there a third option I'm not aware of.

** Picture included **

Thanks.

 

[Reach4]

Another choice is switching to a dual-input air gap with separate inputs for the RO drain and the DW drain.

 

[Sponsor]

 

[TX-Tim]

Hmm, If I'm looking at the correct pictures, that would require drilling another hole in the counter top, which I do not think the wife will go for, as there are already three items above the counter: disposal button, faucet, and existing water filter faucet (not RO system)
There is not an existing dishwasher air gap. The DW drain simply connects to the disposal.

 

[Reach4]

If you will displace the current water filter faucet with RO, you could get a dispenser faucet with a built-in airgap. That still leaves the main question of how to introduce the RO drain water -- wye with the dishwasher, put a saddle on the curved black disposal discharge tube, or put a branch onto the path from the disposal to the p-trap.

I think I would opt for the saddle on the vertical part of the black discharge tube. I am not a plumber.

 

[WorthFlorida]

.............existing water filter faucet (not RO system)............

Google "RO faucet with air gap". You can replace the filter water faucet with an RO faucet with a built in air gap. You'll still need to pierce into the the drain somewhere but at least there is an air gap to prevent cross contamination.

There are under the counter air gap devices out there.
https://www.freshwatersystems.com/p...qBkQciqhchXIaQbY0CQPHsY30lBx7JewaAvH-EALw_wcB

 

[TX-Tim]

Yes, unfortunately, my wife picked an RO faucet that is not air-gapped.
Not just any faucet. It had to have the right curve, handle, color (matte black) which greatly cut down the choices.

I was not aware of an under counter air gap.
Thanks for the comments/ideas thus far.

 

[WorthFlorida]

Just be sure that an air gap is mounted high as possible. A full sink of water going down the drain could backup to the air gap but not likely through a 3/8” line.

 

[TX-Tim]

Due to proper mounting height, the wall mount air gap may not work as the drain from the RO filter is on top of the unit. I did happen to find this from AirGap, which seems better than the saddle:

Reverse Osmosis parts for under sink

 

[WorthFlorida]

Looks good

 

[DavePA123]

TX-Tim. Did that part work for you? I have a similar situation and while the company said it was ok to install the drain after the trap, I want to find a way to install before the trap. See attached image. Any suggestions?

 

[Reach4]

I have a similar situation and while the company said it was ok to install the drain after the trap, I want to find a way to install before the trap. See attached image. Any suggestions?

If that photo is what already exists, then you would replace that chrome tailpiece extension with one that has a branch.

A plastic one is easier to cut to length. Run the output of the RO air gap to the branch.

 

[DavePA123]

Thanks for the input. Isn't the RO output just a plastic tube that drains the water? Is the branch in the picture above capped? And would I just drill a hole on the top of the branch for the saddle?

 

[DavePA123]

The system I am looking at, APEC RO-HI doesn't have an airgap faucet. https://www.freedrinkingwater.com/ro-hi-detail.htm.

 

[Reach4]

Thanks for the input. Isn't the RO output just a plastic tube that drains the water? Is the branch in the picture above capped?

No. Those are open tubes that you attach a draining device to.

The system I am looking at, APEC RO-HI doesn't have an airgap faucet. https://www.freedrinkingwater.com/ro-hi-detail.htm.

You can have a separate air gap, or get a different dispenser faucet. See IPC 611.2 to see if you think you need an airgap.

 

[TX-Tim]

Yes, that part worked great. I even added an air gap on the back wall, since the faucet my wife wanted was not an air gap faucet.

Here is what a used:
RO Air Gap: https://www.amazon.com/gp/product/B01ENLOP20/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
RO Drain Line Adapter: https://www.amazon.com/gp/product/B078TKB67J/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

Here is a pic. It is a little crowded, but you can see the drain line go straight across from the air gap to the drain adapter.
I cut the flanged tube shorter than I intended, but I'll eventually get to Home Deport and replace it, so the collar is not so close to the disposal.

I put a 90 degree JG push fitting at top and bottom of the Air Gap (with a short piece of tubing) to change the direction and make the tubing connection easier.

 

[JerryR]

We used this adaptor for the RO drain. https://www.amazon.com/gp/product/B009XDMEK4/

We had to also buy a 3/8” stem to 1/4” tube adaptor. https://www.amazon.com/gp/product/B078VP98D2/

it works very well