Recent Texas 105 degree heat made it difficult for my 15K A/C to keep up (even after covering the sunlights and vents). We found that during the day it was best to block the rear bedroom and bathroom AC vents, then at night block the living room vents. This forced more air into the opposite side of the trailer with the unblocked vents. Blocking vents was a hodge podge of using a broom handle to hold a pillow up etc. (quite hilarious, but it helped). I searched the net and found a better solution when we got home.
D&W Inc. in Elkhart makes the circular, vented A/C covers that Dutchmen uses. The factory installed ones can be turned to direct the air but they have no way to close off a vent. I contacted D&W and they suggested I replace them with model 5840BTW which is an exact fit for the factory ones. The screw holes line up, the circle cut is the exact same size. It took 10 minutes to replace the three I wanted to be able to close.
Visit this link
http://dwincorp.com/index.php?cPath=...9aa2e6d47ff4bf
Basically, 5840 is their non-louvred version. They cost $2.75 each, I ordered 3 (note: shipping is $8.50 for total box, cheaper to get extras in one shipment). The 5840 twists open and closed. Air is deflected outward along the ceiling, not down as in the louvred version. You have to do a little modding if you want to be able to close them completely though. At their closed position they still leave a slight gap due to tiny little plastic nubs that keep it from closing all the way. I unscrewed the closing part and used simple wirecutters to snip off the nubs. The second step is that you also snip the plastic hub down about 1/8 ". The modified vent cover can now be screwed completely closed. One word of caution though, if you decide to replace all the vent covers (not a good idea I think since louvered is nice in some places) be sure to NOT modify all of them. Your A/C needs to have some escape such that all pressure isn't forced back to the unit.
I have a Kodiac 242RESL, I replaced the one in the Bathroom, the one in the Bedroom and the one at the end of the trailer near above the sink. Except for the really 90+ days, I'll probably leave all vents completely open, it's just nice to close off some if I want.
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