Vent cap mods

[Ron in BC]

Looking at the vent cap one thing puzzled me. It's symetrical yet one end faces rain and hail hitting it at highway speeds. But the "front" does not have the 1" high lip the sides have that would offer more resistance to rain being driven in. You can put your fingers in the front and easily touch the mesh.

Also, the material is thin and mine had warped and was sloped to the inside. So I made a lip to match the side ones and now my vent has a "front" and "back". This may also be better at preventing the flame from blowing out at highway speeds, who knows, but I did it primarily to prevent leaks.

Also, I lined the underside of the cap with reflectix to try and limit the heat from solar gain. I'll never know if it helps a wee bit but it didn't cost anything so I did it.

Ron

 

[tractors1]

I've been toying with mounting exhaust fans way up there to possibly help with fridge cooling............

 

[Ron in BC]

I was thinking of doing that too. I was thinking that a crossflow fan might be a good type for that area because there're more linear. If one was placed under the condenser that would be a pretty good flow of air. Or a couple of small computer fans, haven't decided yet. Another project for another day

Ron

 

[tractors1]

Computer fans would be cheap and easy to mount; if the added airflow proved effective I might upgrade to a better crossflow where I could vary the speed for quietness. I have found mounting more than one cheap 12V computer fan can result in a "beat rate" noise due to speed differences.

 

[Ron in BC]

Finished off the baffle project and re-installed the vent cap. The flange material is very thin and was warped so I used fender washers under the screw heads. ETI uses dollops (highly technical term ) of sealant to cover the screw heads but I used EPDM washers to form a compression seal instead.

Time will tell if the ducted baffle project works or not.

Ron

 

[fudge_brownie]

So it looks like the new lip you fabricated is a rectangle of sheet metal? Do the existing lips stay in place and how is it fastened?

I have not been inside my vent yet so you are talking to the uninformed.

 

[7th Heaven]

has anyone looks imto the solar roof vents:
http://www.amazon.com/Camco-42165-R...=8-1&keywords=solar+powered+roof+vent+dometic

 

[Brian B-P]

has anyone looks imto the solar roof vents:
Amazon.com: Camco 42165 Refrigerator Solar Roof Vent System: Automotive

The shape makes sense, but this product does not include the base part, so it won't address the issues which Ron raised.

I see some logic of the panel to run the fan in an RV without any solar panel, but if the trailer already has much bigger and better panels, the little panel on this vent doesn't make much sense to me. Also, it appears from reviews that at least the early panels were poorly constructed.

 

[tractors1]

has anyone looks imto the solar roof vents:
http://www.amazon.com/Camco-42165-R...=8-1&keywords=solar+powered+roof+vent+dometic

I bought this exact item and sent it back after I pulled it out of the box. It is VERY poorly made with thin plastic. I figured it would crack in a year or so, and the solar panels are hot welded in place - can't be repaired.

 

[Ron in BC]

So it looks like the new lip you fabricated is a rectangle of sheet metal? Do the existing lips stay in place and how is it fastened?

I have not been inside my vent yet so you are talking to the uninformed.

Yes, the front lip or rim that I fabricated is a piece of light aluminum. It goes down each side an inch and a small sheet metal screw holds in place.

The part that extends forward is there because, as you might be able to see in the first photo, the base is warped and slopes to the interior. The new front rim was bedded in caulk to seal it.

Ron

 

[Ron in BC]

has anyone looks imto the solar roof vents:
Amazon.com: Camco 42165 Refrigerator Solar Roof Vent System: Automotive

It did cross my mind to do that using the smaller type without the whole cap. But it didn't seem to make too much sense because the suction would be almost right by the intake and I'm not to sure how efficient that would be. And as Brian mentions when you have a ton of solar you don't really need to be adding something with a dedicated solar unit.

I think that Klem's location for adding a fan to remove heat from the condenser is a great way to go and when I have time that's what I'm going to do.

Ron

 

[markvt]

Is more better

Ok Guys what is your opinion ? I was talking with Paul Unmack from ARP LLC I consider Paul an expert in absorption refrigaration. I ask Paul how much ventilation I need it for my Dometic 6.7 fridge. He said one air exchange a minute any more then that would not help you any more. So he recommended one 16 CFM fan for my Escape 19 trailer. If Paul would of recommended more fans I would purchase what ever he suggested. Now I am kind a person that would have thought the more air flow the better off you are.

 

[tractors1]

Ok Guys what is your opinion ? I was talking with Paul Unmack from ARP LLC I consider Paul an expert in absorption refrigaration. I ask Paul how much ventilation I need it for my Dometic 6.7 fridge. He said one air exchange a minute any more then that would not help you any more. So he recommended one 16 CFM fan for my Escape 19 trailer. If Paul would of recommended more fans I would purchase what ever he suggested. Now I am kind a person that would have thought the more air flow the better off you are.

Actually if the airflow is too rapid, there is less heat transferred since the air has less time to be in direct contact the hot surface. There is a "sweet spot" that depends on the design of the fins (impingement surfaces.) Retired HVAC design engineer here.....

 

[markvt]

Charlie,
I agree with you I am actually a license refrigeration mechanic to. Refrigeration is not my field of expertise but I am required to work on it at times. I put this question out because it appears that a lot of people think they should have a windtunnel blowing behind the back of there refrigerator units.
Mark

 

[MyronL]

Re, Vent: I was up on my roof to remove the manual vent where an air conditioner would go and happened to glance to my right at the (other) plumbing vent over the sink. Saw, to my utter amazement, the vent cap had vanished.

Looking back at pictures taken of the trailer the last few months I was able to determine this cap, judging by how crooked it looked, must never have been correctly seated. It seems to have finally broke loose and flew off on the last trip.

Finally found a replacement on eBay.

 

[fudge_brownie]

Ron,
I have used your method and fabricated an aluminium rim around the inside of the upper refrigerator vent. It was an easy process and gave me a chance to inspect the inside and check for leaks on the screws. Everything was OK but in my subsequent travels I did not find the solution helped my refrigerator from warming up while travelling.

So far the only solution is to completely block the lower vent with a closed cell foam while travelling. However this solution is still in testing as I need some 3-4 hour travel days to get a true result.

 

[vermilye]

Myron - did you find a replacement cap that fit or did you have to replace the entire assembly? The vent cover assembly that Escape uses is somewhat flexible & curves to the roof (at least on the 17). The assemblies I've been able to find are too stiff to follow the roof curve.

 

[MyronL]

You know at first I could not find this cap listed anywhere on my bookmarked rv supplier sites. Maybe because with my searches I didn't know what to call it. Then went onto eBay doing a broad search for "...exterior vents..." or something like that and scrolling through the results is how I found what I needed.

The cap is evidently not sold separately -- for seven bucks I got the entire unit. No need to replace entire vent. Simply attached matching new cap onto original vent housing. No screws or metal involved, drop in and twist left or right to snag in the tangs. It actually took several tries to get it locked in.