joelle: Those units look very much like the ones that we installed recently, W6222 washer and T712 dryer. Since the write-up mentions rental use, I assume that some features may have been eliminated to save costs, but you'd have to do a comparison to be sure. One cosmetic difference is that my washer has an outer, drop-down door in addition to the inner glass door. It's just for looks, I guess, since you can leave it open and watch the exciting action inside the washer. We are very happy with these machines, and I would recommend them. I'm not sure what you mean by regular plumbing drains. Do you have laundry machines installed at these locations already? If not, you will need to talk to your plumber and electrician for codes, etc. Note that the washer is 220v, and plugs into the dryer. So you only need one 220v, but it has to be 30 amp, if I recall. Also, your title says "ventless" so I assume you mean the condensation dryer, which is available in that model. We have a vented dryer, so I don't have first-hand experience with the condensation model. From the posts on this forum, many (some?) people don't like condensation dryers, but some do. If you can vent the dryer in some or all of you locations, you might want to consider it, because I imagine that drying times would be quicker. The Asko vented dryers can be vented from the rear or either side, which is a plus as far as flexibility of installation.

Thank you for your response and sorry for the late follow up. Some features have been eliminated on these machines to facilitates guests use (we are in the vacation rental business) without compromise quality of washing/drying.
These particular machines are sold to condos who were not built with W/D setups, so you can actually use regular plumbing for your washer instead of a different type of plumbing stack made to sustain Washers on each floor. The flow is the same as a dishwasher. We are not able to vent the dryer as we are further than 15 feet from an outside wall (code requirement), so the ventless dryer makes sense in our case. Also the condensation dryer attaches to the drain so there is nothing to empty (like in some dryers in europe) after each use. Are you happy with the load size of yours? it looks similar to this one which says that you can wash 14 bathtowels at once.

joelle, We're happy with the load size, BUT we also have full size (older) machines in the basement. We haven't tested the Askos with 14 bathtowels, and frankly I'd be a bit skeptical about that. But maybe it would work. Our washer has a 1200 RPM spin, which gets the clothes pretty dry before you even have to put them in the dryer. You might check to see if the rental machine has the same. Generally, I would think that the Askos would be fine for vacation rentals, provided the cleaning crew is not using them to do linens for multiple units, etc. Also keep in mind the longer cycle times for front-loading machines.