Very quiet and effective.

Since cutting down some trees next to our house, the central AC hasn't been able to keep pace this summer. The hottest room is the small office in the corner of the house where several computers heat up the room. I installed a roof power ventilator then went shopping for a portable AC. A window AC unit will not fit the window in the office, so a portable was required. After shopping around and reading reviews, I selected the Sharp for the noise rating and the few reviews I did find were favorable. Fry’s had them in stock, so I brought one home. Since this is a permanent installation vented into the ceiling, I can't comment on the window kit. I placed mine on top of our filing cabinets to keep it out of the way and minimize the exhaust hose length. The exhaust hose is hot, so keeping it as short as possible will maximize efficiency.

Most of the instruction manual deals with installing the window kit. Since I didn't use the window kit, I have little to say about it except that the window kit seems to be nicely designed with an insect filter and rain louver built-in. I was able to use the insect filter and louver in the ceiling drywall installation. The foam included seems to be enough for the job.

It has four modes: AC, Dehumidify, Fan, and Ventilate. The first three seem obvious. The Ventilate function will draw air through the unit out the exhaust vent. That's an uncommon feature in portable A/Cs. In AC mode, it has a "Mega Cool" sub mode that maximizes cooling - extra high fan speed and a low thermostat setting of 59F. It remembers the last mode on power-up.

Fan speeds are Auto, Low (quiet), medium, and high. Extra high in Mega Cool mode. It will remember the fan mode on the next power-up.

The remote is clearly labeled with icons that coordinate the buttons with the display. Functional areas are marked off nicely. If you lose the remote, the unit will become MUCH less useful. There is a hook on the back to store the remote.

It has a "Plasmacluster" mode that emits positive and negative ions. Not sure what else to say about that.

Exhaust louvers control the airflow vertically and horizontally.

The left-right louvers can be set manually. There is a set on each side so you can set the flow to diverge, go to the left, or to the right.

The up-down louvers are controlled with the remote. There are two modes. Push the louver button once and they start cycling slowly up and down. If you wait until they are where you want them then press the button again, they will stop moving and stay there. They automatically close and cover the exhaust when the unit is off. When the unit powers up, they return to their last mode or position. Nice!

There is a 1-hour off timer for intermittent use. Push the one-hour button to run the unit for an hour at the last temp, mode, and louver setting.

It has Off timer and On timer modes. These modes will turn the unit off or on after your preset timer setting. The timer setting can be set to 30 minutes up to 10 hours in 30-minute increments then up to 11 or 12 hours in hour increments.

This AC has the evaporative cooling feature that is becoming more common. Condensation is pumped over the compressor coils to be evaporated and carried out the exhaust. In case the humidity is too high and the reservoir fills up, the unit will stop and await drainage. Draining the unit is accomplished via two hose connectors with stopcocks on the back. I haven't had to drain this one yet, but you'll need a hose (not supplied) and a bucket to do so. If you run it in dehumidify mode, the directions indicate that you should connect a drain hose permanently. The reservoir capacity is not easy to find in the manual, but it says it will drain up to 4.2 pints when full.

Maintenance: Sharp recommends cleaning the filters and insect guard twice a month. The filters slide out of the right side and seem to be easy enough to clean. Before long-term storage, run the fan for several hours to completely dry the unit.

I'm happy with this AC and have no reservations about recommending it to anyone.

I compared this unit to several others. This is the only one I could probably sleep next to. It's quiet enough to have a normal conversation next to it without raising your voice. Sharp rates it at 39db. The others I tried that have sound level ratings are all in the 50's - MUCH louder (but less expensive).

I rated it four stars for durability and ease of cleaning because I haven't had it for very long.

UPDATE. After two summers with maintenance consisting of only filter cleaning, I can upgrade the durability rating.