This unit is very easy for a one-person installation. The dual-hose ventiliation window kit is much more efficient than the tradional single-hose units. It has a self-evaporation feature that eliminates the need to empty drip pans. The removable, permanent filter saves money as it it only needs to be removed and washed - no expensive disposable filters to purchase.
It adequately cools a room of about 300 sq ft.; sometimes the air doesn't need to be on as the fan blows nice, cool air. I'm not sure on the energy efficiency issue, but I've noticed my electric bill has only gone up three or four dollars. It is much quieter than a window unit, so noise is not an issue. It can be moved from room to room, but, of course, the window kit will need to be moved and reinstalled, but only takes a few minutes.
I purchased this through HSN (Home Shopping Network) and paid $449.95 as it was on sale at that time; it is now $549.95, but even at that price, it would be worth it.
It is more expensive than most window units, but I needed this type of portable a/c as I don't have anyone to help me install one, plus it can be easily moved to another room if necessary. It is 12, 000 BTUs and is 115v, which fits 110 homes.
I would recommend this product.