The DeLonghi range includes a number of air conditioning devices for varying room sizes. They are all portable, allowing you to cool only the room you are occupying. The PAC T 90 ECO, shown with this article, has the highest energy efficiency rating, "A", according to the European standard.
Most of the DeLonghi air conditioning devices also condition the air on all levels: they are fully functional as dehumidifiers, including hydrostat so relative humidity levels can be set by the user. They can be used in the dehumidification mode alone, which is often enough to make a room feel comfortable. They are also outfitted with 3M electrostatic air filtration technology, so they clean the air which they circulate. The fan has an auto-function device to optimize fan speed based on the current room conditions, and there is a timer so that night-time function can be set.
The devices use the coolant R 290, a non-fluorocarbon refrigerant. R 290 is considered a "natural" coolant by the air conditioning professionals, and has a very low global warming potential (GWP) compared to the engineered coolants; it is actually a trade term for propane. It is slightly less efficient than other cooling agents in studies, but given the "A" efficiency rating of the DeLonghi air conditioner, we would say this is not a concern in this application. The chemists out there may recognize R 290's other drawback: propane is flammable. This implies some extra cost for safety engineering in its use. Some studies suggest that with the extra cost of safety calculated in, the Life Cycle performance of some fluorinated chemicals is still better than the R 290. (Of course, these studies usually assume no losses, while the refrigerants industry estimates that 1/3 of aftermarket refrigerant sales cannot be accounted for--presumably lost to the environment.) We suggest you look at the DeLonghi products, which presumably meet the standards of consumer safety laws in Europe and therefore already reflect the safety costs, and decide yourself if it is worth the price. [by © C. Lepisto]