As a former employee i can tell you the Emerson Quiet Kool Corp was
closed in 1993 after it was purchased by the Fedders Corp .

Fedders still produces product with the EQK logo. Your only hope is to
contact Fedders Customer Service or Ebay.

Thanks for the info. I have already contacted Fedder about this. They
can send me the instruction manual as long as I can give them a model
number. Unfortunately, I cannot find the model number anyway that I see
from outside of the air conditioner. I am afraid that the model number
tag might have come off a long time ago. I am sure I can find the model
number as soon as I open the front panel of the air conditioner and
look inside. But I don't know how to open the front panel without
breaking it and without the instruction manual -- kind of a "chicken
first or egg first" situation. If they could have given me the pictures
of the various models, I might be able to identify the model from the
pictures. Unfortunately, they don't have the pictures. Oh well...

Currently, I really don't know what to do. May be I will carefully open
the front panel. But I will not do this until the hot summer is over.

Jay Chan