Bug Screens vs A/C Head Pressures?

[FDziurda]

The other day, a friend, who works on automotive A/C systems, noticed I had installed a piece of window screen across the front of my radiator, to keep the bugs off.



He suggested that I might want to consider removing it, due the the air restriction that it caused. He told me that the screen would probably not have been a problem in the days before Freon 134 systems, but the newer systems run at a much higher "head" pressures. Any additional air-flow restriction can increase these pressures quite a bit, and cause blown hoses, or worse.



To get an idea of how much air resistance the screen adds, he suggested taking a piece of screen and mounting it in a frame and holding it in front of you and see how far and fast you can run. Then try running the same distance without it. Either way would probably kill me, so I decided this was not a test I could use to verify his explaination.



I have seen posts talking about putting screen in front of the radiator but never anything that would suggest this could have some drawback.



What-say some of the A/C experts here on the board. Window screen okay or clean them bugs?

 

[roadranger]

The screening DOES cut down on airflow, as I've learned with Broadcast Radio transmitters.

I didn't know it affected the newer A/C systems that badly...



I don't have any screen mounted in front of the radiator, but I do have a soft-bristled hair brush stuffed under the seat that I use to clean out the fins when fueling up and the windshield needs scraping...

 

[Archive]

I use a screen in front of my radiator. I have since 1971, with no bad effects on temps, etc. I have towed many times in 100 degree heat with it, no problems. Does it restrict some air? Of course it does, but IMO, not nearly enough to worry about. Like the hair brush trick above, you simply have to maintain it a little bit. When you wash your Ram, pull out the screen and rinse it off.



This subject has been bantered around quite a bit... it went from restricting the air to your radiator, to restricting it to all coolers, to the intercooler, and now to the air conditioner condensor.



Do what you are comfy with... and enjoy your Ram.

 

[ASchwartz]

I am currently using a screen and I have not seen any increase in temp. I don't have a plastic one for windows. It is made of metal and has a slightly larger mesh pattern. I am not sure where I got it, but it works wonders. Besides, what size bugs are you trying to keep out?

 

[EMDDIESEL]

I like the idea of window screen, but i went with the next best thing, a Stull "Diamond wire" grill. It is a much finer mesh pattern then the stock honeycomb, but small enough that big bugs dont get through it. I is also made out of stainless steel.

 

[KatDiesel]

Originally posted by EMDDIESEL

I like the idea of window screen, but i went with the next best thing, a Stull "Diamond wire" grill. It is a much finer mesh pattern then the stock honeycomb, but small enough that big bugs dont get through it. I is also made out of stainless steel.

Diamond Wire? Sounds interesting, got any pictures??? Thanks

 

[Steve St.Laurent]

Kat, you saw it on my truck last year. Here's a pic of mine:



#ad

 

[KatDiesel]

Originally posted by Steve St. Laurent

Kat, you saw it on my truck last year. Here's a pic of mine:

Ok so its the same as yours? "Diamond Wire" jsut sounded different from yours is all, I just rememeber yours being Stull.



Thanks Steve.

 

[EMDDIESEL]

I am still waiting for my factory replacement from Stull. The original version i got was welded wrong, they are sending me a new one. EVENTUALLY

 

[Evan A. Beck]

Anyone who wants PROOF the screens cause a restricition can try this simple test...



All you need is a piece of screen, a household cooling fan (box type, or whatever), and about 10 minutes.



Turn the fan on high speed, and note the amount of air it is pushing without the screen in front of it. Now put the screen about 6-12" away from the grille of the fan. Check the airflow now. If there a restriction? Yup. 'Nuff said.



Bugs are easy to clean off, the design of the Ram makes it that way. Lift the hood, and hose away.



Overheating is not a concern here at all, and nor have I ever said so. I think most of you will agree with that. The main problem is that the screens restrict flow across the intercooler, and causes an efficiency problem. The problem becomes worse when you have your A/C on, because of the heat coming from the condenser. I have observed a rise in intake temperature using a scan tool when there is a screen present on the truck. The problem is amplified with the A/C on.



What's all this mean? Well, basically, it means if you want the MAXIMUM efficiency from your intercooler, take the screen off! The only instance where a screen is necessary is if you drive through a lot of bug-saturated places on a regular basis.



I drive 700+ miles/week, and about 25 miles per day is going though areas where there are pastures... Pastures = cow poo = bugs. I have no screens installed, and I do not have a bug problem at all. Just hose the thing off once a month, and it looks like new. Doesn't get any easier than that.



If you feel you MUST have a screen, use the large opening kind, with squares about 1/8" or bigger... The small 1/16" screens are just too restrictive.

 

[Shooter]

returning home from MM between Kingman and Williams my temp went to 220+. BUGS. I cleaned the rad best I could at kingman as between LV and Kingman hit 210. Now with that being said: Thoes bugs do not just stay on the outside plane of the intercooler fins. They wedge themselves into the radiator fins and cook on. I did not pam the grill before the bug barbeque and thoes babies were in there for the duration of the trip. I have a screen now that usually needs sweeping every other fill up, and every 1/2 fill up in TX. ( big juicey grasshoppers and other fat low fliers). They wash off the screen with a bucket, I dont have to use a wire brush and a tooth pick to clean the heat exchangers.



MHO

 

[Archive]

Originally posted by Evan A. Beck

Anyone who wants PROOF the screens cause a restricition can try this simple test...

Yes, this test would tend to support your claims, but how do you get to the 25% loss? And is this loss detectable in performance?





Overheating is not a concern here at all, and nor have I ever said so.



Evan, on 6/24/01, in another thread, yes... you did! I copied the following from that thread: "Towing coolant temps Go up"

There should not be too much fluctuation in your water temperature as long as your thermostat is working correctly. Also, keep your radiator clean, and don't use any sort of "window screen" to prevent bugs from collecting on the fins. The screen material can cause up to a 25% restriction in airflow, which means all the coolers on the front of the truck will not function to their full ability.





I have observed a rise in intake temperature using a scan tool when there is a screen present on the truck.

Can you expound on this test? Was it with a load, uphill, etc?





What's all this mean? Well, basically, it means if you want the MAXIMUM efficiency from your intercooler, take the screen off! The only instance where a screen is necessary is if you drive through a lot of bug-saturated places on a regular basis.







I drive 700+ miles/week, and about 25 miles per day is going though areas where there are pastures... Pastures = cow poo = bugs. I have no screens installed, and I do not have a bug problem at all.

Are you doing this driving in the daylight, or at night with your headlights on... it makes a difference!





If you feel you MUST have a screen, use the large opening kind, with squares about 1/8" or bigger... The small 1/16" screens are just too restrictive. [/QUOTE

Would this cut the loss of efficiency down to 12. 5percent? At what point does it no longer become a factor?

 

[Evan A. Beck]

First of all, I want to comment on what you think I said... I DID NOT say it has anything to do with overheating.



"Overheating is not a concern here at all, and nor have I ever said so.



Evan, on 6/24/01, in another thread, yes... you did! I copied the following from that thread: "Towing coolant temps Go up"

There should not be too much fluctuation in your water temperature as long as your thermostat is working correctly. Also, keep your radiator clean, and don't use any sort of "window screen" to prevent bugs from collecting on the fins. The screen material can cause up to a 25% restriction in airflow, which means all the coolers on the front of the truck will not function to their full ability.



Maybe I am not seeing it, but I DID NOT say anything about overheating...



As for the headlight thing... I have done both, and I have MUCH brighter headlights than most, so there should be more bugs, right? Well, it didn't make much of a difference at all. Also, I have done a lot of driving all around the country, day and night. Yeah, some areas had a lot of bugs, but it didn't make any difference, night or day.



Yes, the loss is detectable in performance. Higher intake temp = less dense air, which means less oxygen. That's why users of a PSA or other device have seen slightly better economy, etc. Cold air = better combustion. Also, the 25% figure came from the owner of the shop, not me. Do you doubt him? I can say for sure you wouldn't be hounding him like you are me on this topic. I think you need to have a long discussion with him about this issue and then decide what you want to believe.



The test was done uphill, under load. Truck was a 2000 3500, with an AT. Truck weight, 8,000 lbs. Trailer was a 4-horse, with quarters, wieght of about 7,000 lbs. Intake air temps were about 50-60° higher with the screen in place.



As for the screen opening issue, I did testing with 3 different types of screen in front of the fan... 1/16", 1/8", and 1/4". The 1/16" was the most restrictive, because there is more material per square inch. 1/4" had the most flow.



***All this testing was done without any high-tech flow meters, etc. It's not really needed, since you can FEEL the difference just by putting your hand in the airflow. ***



I look forward to youir reply on this. Maybe you should do some testing of your own?

 

[mbrolin]

Ive used the screen with no ill effects whatsoever. This was while pulling the 5er at MM in Vegas when it was over 100 deg also. Just keep it clean as the bugs and dirt tends to build up faster.

 

[Archive]

Originally posted by Evan A. Beck

Maybe you should do some testing of your own?

I have tested this on every vehicle I have owned, since 1971! This is one of the reasons why I disagree with your statements! Cars, Jeeps, trucks.



This will be the last of my response... if your response I quoted was not about overheating, maybe it is just my impression that you implied it. I have been wrong before, but after all, you posted on a thread titled... Towing Cooling Temps go up. You then go on to say that it affects ALL coolers at a rate of 25 percent.



I have already had this discussion with Chuck, as he saw my screen when I first brought my truck in there. I did not see any real proof then, nor in your post.

 

[Evan A. Beck]

Try the fan test. You'll be surprised.

 

[illflem]

I've run window screen on my trucks since new and have noticed no rise in temps, this includes intake temp, which also has gauge, sender on the manifold. Heck, I haven't even seen temp increases with a Lund winter front! Just removed and pressure washed out the bugs on a GMC radiator last week, it was running in the red. I know which method I prefer. The screen may restrict, but plenty of air still flows past. If a person is concerned just run 1/8" screen.

 

[Mundgyver]

I use a doubled over 1/4 inch galvinized fencing material. Some call it construction screen. I use it mainly to prevent pebble injestion into the fins. It does a real nice job of breaking up the bugs also which just wash off and out of the mesh. I do not have to worry about getting the fins blasted on the radiator or air conditioner.

 

[John Berger]

I try to hose my radiator and intercooler down a couple of times a month. It's easy and doesn't take all that much time. It's bad down here most of the summer, but the lovebugs in the spring and the fall are the worst.

 

[JJW_ND]

1/4" small enough to help!

We run the 1/4" hardware cloth tie rapped to the grill. We do this more for rock protection (gravel roads) then bugs. This size seems to let the little stuff through that does not get hung up on the radiator or intercooler but stops the bigger hoppers, midges.



We had our problems with 89 chevys trucks with 454 big blocks and way to small of factory radiators. THey never ran under 230 degrees in the summer, could not rest your arms on hood, and most boiled into the overflow jug everytime you shut off engine. Worst case was an overheat that melted the brass sending unit after just 5 minutes post shut down from temp gauge coming on. This truck had 3000 miles on it at the time. Just standing infront of those trucks caused them to overheat.



jjw

ND