Forum Discussion

udidwht's avatar
udidwht
Explorer
Sep 10, 2022

Front grill filter

Improvised a filter made from HVAC 'cut to size' filter media that is weather proof and washable with a hose. This will greatly reduce the dirt, silt, dogwood, debris etc...from coming in and plugging up the condenser and radiator.

See here:

https://www.rvforum.net/threads/front-grill-filter.140388/
  • The previous owner of my 1999 Southwind Class A (Ford F53 chassis) zip tied some cut to fit 1/8" square galvanized steel mesh to the back side of the front radiator grill. I painted it all flat black so it isn't really visible from the outside. So far, it seems to do a pretty good job of keeping road debris, bees, grasshoppers, butterflies and other flying pests off the AC condenser, the transmission cooler, and out of the radiator/engine bay. Even on the hottest days, overheating has never been an issue. I spray it clean with high pressure water from the inside as necessary.

    I never drive in freezing conditions, but, I can see how it might be an issue with freezing rain, hail, or with large snowflakes. So far, so good.

    Chum lee
  • Holding up very well. The material is 100 percent polyester woven (weatherproof) high efficiency. It's purpose is not to increase airflow into the radiator but to decrease the following...

    https://www.rvforum.net/threads/ac-condenser-w-oil-cooler.139788/post-1315171
  • udidwht,

    I think I'm going to have to side with the folks that think this might create a worse problem due to excessive heat. As wolfe10 mentioned, take a piece of that material (I'd think 1' x 1' would be enough) and while someone else is driving, you hold onto it with both hands and stick it out the window at highway speed. The air rushing toward that material will see that material almost like a wall, a higher pressure area will be created in front of it, and incoming air will be deflected around the material by that higher pressure. The same will happen in front of your radiator and you'll be limiting the amount of fresh, cooler air, getting to your engine. Vehicle manufacturers usually spend a lot of time making sure that proper air flow exists under a wide variety of environments. Remember that fluid flow is from high pressure to low pressure. A high pressure area in front of that material will cause the air flow to find a lower pressure route.

    As others have said, carefully monitor your temps. Even if things are just running moderately hotter, higher operating temps tend to shorten the life of lubricating fluids, transmission fluid especially, so you might wish to shorten those change intervals.

    The material you purchased is used in an application where there is a low pressure area created behind the filter by the circulation fan in the A/C. It is also (usually) contained in a rigid frame so air must flow through it, and it is not exposed to the elements (moisture especially). The air is drawn in THROUGH the filter. The air filter in your engine operates the same way, the low pressure inside the intake manifold (due to the intake strokes of the pistons) draws air through the air filter with atmospheric pressure on the outside creating the pressure differential.

    One other thing I thought about...you said you held it in place with zip ties. LOL...I'm a "zip tie guy" myself. But that foam material isn't that strong. If the material rips free, can it get "sucked in" to the radiator or go underneath and get wrapped around the fans and belts? Just a thought. I could be way off base with that, but figured I'd mention it.

    Oh...just had another thought...what about in the rain? That material will get heavier and stress those zip tie connections even more, while further limiting air flow.

    Personally, I'd think you'd be better off with hardware cloth (actually wire mesh). I think the size they recommend for "rock catchers" is 1/2" x 1/2" holes. It might not catch everything you want it to, but it should help and will pass a lot more air. Until/if it becomes clogged.

    Hey...it's your rig. Maybe it'll work and won't cause you any problems. We'll keep our fingers crossed for ya'! :)

    Good Luck,

    ~Rick
  • I grew up in the South Alabama, North Florida and we have Lovebugs and the only way to stop from replacing your radiator and anything else is put a bug screen in front of the radiator. All it is window screen with a band around it with mounting rings. Our vehicle do not over heat. This is replace as needed when they fill up with the bugs. If you do not wash the vehicle everyday then you will have no paint in one season.

    I now live out West and use the screen on all my vehicles to keep out the bug and flying things. We get up to 110 last year and non of our vehicles overheat. We must be lucky. Been doing it for over 50 years.
  • In the maintenance presentations Chevy used to do when they sold the P chassis, they were adamant that anything other than hardware cloth (to stop rocks) was a very bad idea.

    Their suggestion was if you thought what you were going to use did not restrict air flow was to take a 3' by 3' square of the material, drive 60 MPG and hold it out the window. You will see the restriction/DRAG very quickly.

    If you want to improve air flow through the radiator, block off access to wheel wells, etc. Basically the objective is to force all the air that comes through the grill to go through the radiator, not "seek" the low pressure areas below the radiator and front wheel wells.
  • If you watch your water, oil and transmission temperatures closely, as most of us do, I’d give it a try.
  • Hope you’re right. The difference, as I see it, in the AC system or the engine air breather, the air is pulled through the filter by the AC fan or pistons, and as the filters get dirty it affects airflow. In both cases there is no other way for air to enter the system. In your situation there is not that forced pulling affect through the material.

    But I could be wrong, and again hope you are right.

    I remember reading a post somewhere could have been on another forum, someone did a similar upgrade on a Jeep but used screen door material and started getting over heating situations.
  • wildtoad wrote:
    I think that’s a bad idea as it will greatly restrict the airflow into the engine area.


    Not at all. Air flows thru it relatively easy. It's used for filtration of incoming air into HAVC units. Flow is easier than an air filter on a carb or TBI. Will greatly reduce the debris coming in that ultimately gets trapped in the condenser and radiator.

    Can be washed out easily with a flow of water from back side.
  • I think that’s a bad idea as it will greatly restrict the airflow into the engine area.