the RPZ prevents a cross connection, Its just not supposed to be installed in the dirt. An RPZ doesent suck air, Its for protection against cross contamination due to dangerous pressure drops. the 2 checks are seperated by a positive gravity drain to eliminate any possibilty of cross contamination. Are u sure u have an RPZ. "Reduced Pressure Zone backflow preventer"?

We got the (new) KA built-in with in door ice/water dispenser. We chose it for a number of reasons, but the two biggies--we liked the fact that the ice maker/holder itself is in the door, rather than in the freezer compartment. This frees up some shelving space in the freezer where we prefer having the shelf space, rather than in the door. Second, we liked the shelf/crisper configuration in the fridge compartment. It seemed like it would suit our needs the best. Another plus, is that for a built-in, the price was lower than Viking, SZ, Thermador..... The fridge comes with a built in water filter (Pur), but we also have a house filter on the cold water line going to our kitchen (sink, pot filler, and fridge), so the water dispenser water is "double" filtered.

Data on this device may be found on-line, including at the Home Depot web site that I just quickly checked. Better data may be available somewhere else. The thing to understand about RO membranes is that you can get high-ish flow at zero pressure on the output side, or high pressure at zero flow. In this case, at zero pressure you can get 0.34 claimed gal/min (about 20 gal/hr). That might be a tad slow for some people filling pots or watering cans, but fine for a glass of water. (For comparison, my RO system produces about 6 gal/hr into a pump using two membranes, but they are not this new side-flow type.) A way to have one's cake and eat it too is to have a booster pump on the RO output side to keep the pressure at the membrane low and the pressure into a tank high. The tank pressure and subsequent plumbing then determine the flow rate up to when the tank is depleted. The assertion is made in the data that it can fill a 20 gal tank in an hour, but it is unclear if this is a pressurized tank and what pressure the tank is at when empty or when the RO system shuts off. Given their spec, the pressure would seem to have to be zero, with faucet pressure established by some post tank pump. (Atmospheric pressure storage tanks have the advantage of not having to be strong, like a well tank does, but on the other hand do breath from the atmosphere and the air inlet should be well filtered against dust, bacteria, and any chemical odors.) In principle for quasi passive systems with a 60 psi water source and a pressure tank filled to 30 psi when empty, the tank will fill to 3/4 full at 60 psi and the RO will not be able to fill it further. In reality, the RO efficiency will drop quickly when the pressure across the RO filter gets low and 60 psi in the tank is unlikely to be reached. This is why some type of membrane output side pump is needed. Spectrapure, for example, has one driven by the waste water (brine). This pump works in concert with a control system that controls water flow to the RO filters. It is a bit "thumpy" though as it runs, so an electric pump may be better depending on location in the house. kas

I'd say it depends on where you are living. I'm in the Lehigh Valley in Pennsylvania, which is notorious for contaminated tap water, so I have both an Aquaversa and a Brita Filter for pitchers. I also try to stay away from the bottled water too because of the environmental issues. But I would find out how clean the local water is before making any major changes or paying extra money.