I'm trying to figure out if these is feasible firstly. I have a frigidaire 8,000 BTU window air conditioner for my bedroom and I would like to know if the rear of the A/C, ie. (where the heat sink, exhaust fan are located on the back - the half of the A/C where it is on the outside of a window not the inside) can be sealed off to prevent water damage/bugs/dirt from entering in. I'm not sure why this part is exposed to the elements because it needs to be cleaned. Any idea if this area is possible to seal off with something like clear tape?

  • 2
    NO, it is designed to be open. The fan needs to pull copious amounts of outside air from the open louvered sides and blow it across the condenser, it's needed for effective heat exchange. – Jimmy Fix-it Aug 8 '16 at 4:49
  • Do you mean seal around the window to keep bugs from coming in the house? It sounds like you want to seal up the AC vents, which is not okay... but you should have a tight seal between the AC and window. – Ben Welborn Aug 8 '16 at 13:34
  • Sealing around the window is fine. That is taken care of with the materials provided with the AC. I'm mentioning the back area that is majority (ie. 70-80% of the AC) is exposed outside. – Narcotixs Aug 8 '16 at 18:10

You cannot seal the condensing coils. The back is where the heat exchange occurs that allows your AC unit to get rid of the excess heat. You can add a external screen or filter media to reduce dust & bug buildup but this will require regular cleaning. If your system has an vent option to bring in outside air only a small amount of outside air is brought in through the evaporator coil and cooled. Window units should have a slight tilt down in the back to make sure the condensate can drip out the back of the unit this is normal. The slight tilt allows the condensate to drip out the back and any rain water that is on the unit to drain and not enter the home.

  • So the heatsink in the back still has small slits of space and is still exposed completely outside. How would sealing off the sides of the vents/louvers affect heat exchange? – Narcotixs Aug 8 '16 at 18:12
  • The slits on the side is where the air is drawn in for the condensing coil. If the air flow to these is reduced the unit will over heat. I have not had very good luck with newer R134 units that have overheated. Once these overheat even with a complete removal of the Freon and recharge they don't work well. If that happens on the small units like yours we replace them. – Ed Beal Aug 8 '16 at 18:47
  • Interesting. Why do you think that even if it overheats it won't work well after? – Narcotixs Aug 8 '16 at 19:29
  • I am not sure if the newer compressors are the problem because the pressures are higher. The Mill lost 6 or 7 last year that were less than a year old (very warm location) I tried to recharge 3 and none of them worked well compared to R22 they do fine with a simple recharge. – Ed Beal Aug 8 '16 at 22:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.