Window A/C: 9.7 EER = ??? SEER

[Homeowner314]

What would be the approximate SEER of a window unit rated at 9.7 EER?

[motoguy128]

Hard to say. They don't test window units that way. They don't have a TXV, so I don't think the efficiency at lower temperatures is going to improve significantly. It will also tend to short cycle more than a split system at cooler temps. If you run the fan in "auto", I'd guess a SEER of about 11.

[udarrell]

If it has a power saver setting that will cycle the blower off with the compressor to save on electrical use.

Also, that prevents the raising of the humidity because the blower doesn't add the coil condensate to the room(s).

For myself, I like room A/Cs undersized so you can let them run for long periods of time.

Many are programmable as to when U want them to come on. they should have temp-differential SWING settings but doubt any have it.

There is no duct losses with room A/Cs &, if U can figure ways around them short cycling & use a floor sized fan to move the air around where U want it, they usually operate very efficiently & will cool surprisingly large areas of a home.

[Homeowner314]

I've got a couple of bottom of the line 5000k units, one in the master bedroom that I can't really circulate.

This AM I stuck one in the bathroom which has two doors and is in the center of the house. I set up a pedestal fan to blow the air in one door at the AC unit and then out the other door into the main hallway. Kept the main hallway at 76° this afternoon until the kid shut the bathroom doors to take a shower. Temps around 100 outside. I consider it pretty good cooling for 515 watts per unit. I also set the furnace to circulate, which adds another 100 watts or so for 20 minutes per hour.

Mine run the fans all the time when they're turned on, so I try to use them only when I can max the thermostat and let them run a 100% duty cycle.

[udarrell]

I've got a couple of bottom of the line 5000k units, one in the master bedroom that I can't really circulate.

This AM I stuck one in the bathroom which has two doors and is in the center of the house. I set up a pedestal fan to blow the air in one door at the AC unit and then out the other door into the main hallway. Kept the main hallway at 76° this afternoon until the kid shut the bathroom doors to take a shower. Temps around 100 outside. I consider it pretty good cooling for 515 watts per unit. I also set the furnace to circulate, which adds another 100 watts or so for 20 minutes per hour. (Some furnace blowers use 550 to 750-Watts or more, I'd run it the least you can.)

Mine run the fans all the time when they're turned on, so I try to use them only when I can max the thermostat and let them run a 100% duty cycle.

You're doing it right; with the help of a fan it's amazing how much more area of cooling a little 5,000-Btuh unit will do.

[Homeowner314]

I've got a couple of bottom of the line 5000k units...

I can't believe I typed that.
5,000 btu/hr or 5k btu/hr, not 5 million btu/hr.

[Homeowner314]

You're probably right that the blower draws more than 100w.
It's a 4 speed 1/3hp blower, so maybe 150-200w would be a better estimate on the lowest speed. I think I'll shut it down, I doubt it adds any where near that much effectiveness to the 515w A/C unit.