If you put a high loop in the drain hose you won't technically need an airgap BUT code in your area may require one anyway - they do in California. Your contractor may be quoting you code particularly if you have permits for your remodel and need to have an inspection. Some people put in an airgap to pass inspection and then remove it and replace it later with a soap dispenser.

You can also get a soap dispenser that has an air gap built into it.

weissman: Thanks for your reply. Ours is a pretty simple remodel, so no permits and no inspection. I wonder if a "high loop in the drain hose" will be difficult for us, since we have a deep apron front sink next to the dw, and it has less than the usual clearance underneath (it'll be a challenge just getting a disposal under there).

lascatx: That's a good idea, although I already purchased a soap dispenser along with my faucet.

You have space. The drain hose loops high -- behind the sink -- and then descends to the sink drain or to the disposer drain.

Some DWs come with the high loop. Our Jennair (last house) did.

Call your municipality inspector and ask. Can't hurt!

Also check with the dishwasher installation info. Miele has a built in anti-siphon/ air gap. Our city in CA requires an air gap, and I was successful in getting them to accept it without putting in a second one next to the sink. They said they would accept the internal air gaps on Miele and Bosch.

I too live in California and did not install the airgap. I wanted a simple, uncluttered countertop. I was worried about the building inspection and was told as long as there was a high loop for the dishwasher ( I have a Bosch) and there was no garbage disposal, the air gap is not required. I compost the vegetables and coffee grounds and there really was not room under the 10 inch deep, D-shaped sink for it anyway. Therefore no air gap and no problem. I did install the outlet for the disposal should I or a future owner wants one.

I'm in CA and my city inspector won't consider the possibility. Grr.

A high loop without any disposer is OK.

Any high loop, that you make yourself by looping the hose high.
It does not depend on the DW machine "having one".
It does not depend on there being a garbage disposal.

A high loop is the very next best thing to an air gap.
A high loop is such a good alternative that many will say it is as good as an air gap.
But that discussion is dangerous: it is a never-ending game when people start discussing whether an air gap is overkill or whether a high loop is just as good or all anyone would need.

For tips on how to deal with local codes and local inspectors, you are on your own.

HTH
-david

OT - a friend told me they placed an air gap on the countertop - no hole - no hook-up and passed inspection in a neighboring CA town. I am not taking any chances - we will turn it into a soap dispenser following inspection! FIgure if he is making us change the cord on our mockett socketts it is unlikely he would let the air gap slip by ;-)

I have a Miele and from what I have heard not all dishwashers are the same in this respect so you really should be looking up the answer through your DW manufacturer. They all have online specs.

I had my "old" DW reinstalled in my new kitchen. I had an air gap before, the but plumber said I didn't need one any more, and I don't have one. They had no problem installing the DW with a high loop and I have a very large farm sink and a disposal.

The DW works much better without the air gap. The air gap used to get stopped up and flood the counter, and it was just disgusting. I've had no problems in the five years I've been without the air gap, and all I can say is good riddance.