Screen for HVAC Discharge

[Michael G.]

My son called me today and said his AC quit working.
We got his shop vac out, jerry rigged a funnel with duct tape and sucked a died gecko out of the drain pipe.

Later he found one of these on Amazon.

Does anyone use them?

https://www.talkofthevillages.com/forums/attachment.php?attachmentid=99490&stc=1&d=1690662116

Cheers

[Rango]

I would think a piece of screen, held on with a hose clamp would work just as well

[Michael G.]

I would think a piece of screen, held on with a hose clamp would work just as well

Your right except Amazon screen would be easier to clean

[metoo21]

My son called me today and said his AC quit working.
We got his shop vac out, jerry rigged a funnel with duct tape and sucked a died gecko out of the drain pipe.

Later he found one of these on Amazon.

Does anyone use them?

https://www.talkofthevillages.com/forums/attachments/villages-florida-general-discussion-73/99490d1690662116-screen-hvac-discharge-71lfulxzhsl-jpg

Cheers

Great idea. Do you have the Amazon link?

[Paulz]

Great idea….there is a bunch of them (various sizes) available on Amazon. In the past I’ve vacuumed a rather long dead snake out of our HVAC line and twice this year have found a snake swimming in the pool…now I know how they got there. As soon as the sun comes up going to confirm sizes and place an order.

[metoo21]

Found the screens: Stainless Steel Mesh Strainer 3/4" (https://www.amazon.com/gp/product/B0BCDZ32S7/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1)

You may need some 3/4" PVC to add a 3/4 Inch Male Thread adapter. The end on mine is a 3/4 pvc elbow.

[retiredguy123]

Found the screens: Stainless Steel Mesh Strainer 3/4" (https://www.amazon.com/gp/product/B0BCDZ32S7/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1)

You may need some 3/4" PVC to add a 3/4 Inch Male Thread adapter. The end on mine is a 3/4 pvc elbow.
It looks difficult to attach. Why not buy a roll of self adhesive screen repair tape and stick a piece onto the end of the pipe?

[retiredguy123]

Another option is to buy a flexible vinyl pipe cap and drill some holes in it.

[MrFlorida]

I made my own with a pice of old window screen and a cable tie.

[bobeaston]

Part of my routine maintenance is to flush that line with vinegar. Doing that frequently will likely repel the pests, unless they like vinegar perfume.

[Annie66]

I would think a piece of screen, held on with a hose clamp would work just as well

It does ....

[MidWestIA]

just pour water thru the clean out in the garage

[mikeycereal]

Part of my routine maintenance is to flush that line with vinegar. Doing that frequently will likely repel the pests, unless they like vinegar perfume.

During our new homeowner's meeting last year the main builder recommended that I do this once a year. :coolsmiley:

[KeithRiz]

Plus, Amazon screen would look better.

[retiredguy123]

During our new homeowner's meeting last year the main builder recommended that I do this once a year. :coolsmiley:
You need to flush the condensate drain more than once a year. Once a month or so is needed. You don't need to use vinegar. A gallon of hot water will do just fine. That is what Munn's recommends.

[Keefelane66]

We have an S-tube trap (pvc) similar to a P-trap that keeps a water barrier. No insects or lizards yet 12 years

[retiredguy123]

We have an S-tube trap (pvc) similar to a P-trap that keeps a water barrier. No insects or lizards yet 12 years
A P-trap would not have prevented the problem that the OP described. If there is blockage in any part of the drain line, the condensate pipe and drain pan can fill with water and cause the HVAC unit to shut off.

[Keefelane66]

A P-trap would not have prevented the problem that the OP described. If there is blockage in any part of the drain line, the condensate pipe and drain pan can fill with water and cause the HVAC unit to shut off.
His son had a lizard crawl up and die blocking water flow then and vacuumed drain out.. With proper maintenance annual/semi-annual treatments vinegar or chlorine water mixture should eliminate algae from forming a screen will not prevent this only ingress of bugs/lizards. A water trap will do the same.

[retiredguy123]

His son had a lizard crawl up and die blocking water flow then and vacuumed drain out.. With proper maintenance annual/semi-annual treatments vinegar or chlorine water mixture should eliminate algae from forming a screen will not prevent this only ingress of bugs/lizards. A water trap will do the same.
I agree. But, if the P-trap is located near the inside HVAC unit, you may have about 20 feet or so of empty pipe for animals to clog up the pipe. I don't have a P-trap or a screen, and I have never had a clogged drain. But, I do keep it flushed out.

[Keefelane66]

I agree. But, if the P-trap is located near the inside HVAC unit, you may have about 20 feet or so of empty pipe for animals to clog up the pipe. I don't have a P-trap or a screen, and I have never had a clogged drain. But, I do keep it flushed out.
It's similar to a p-trap made out of 3 elbows and and 3 pieces of plastic tubing

[Pinball wizard]

I agree. But, if the P-trap is located near the inside HVAC unit, you may have about 20 feet or so of empty pipe for animals to clog up the pipe. I don't have a P-trap or a screen, and I have never had a clogged drain. But, I do keep it flushed out.

Stay away from using Bleach in your drain line. Over time, it can deteriorate the glue that holds the PVC pipe together.

[retiredguy123]

It's similar to a p-trap made out of 3 elbows and and 3 pieces of plastic tubing
Note that the plumbing code requires all drain lines that are connected to the sanitary sewer system to have a P-trap installed on them. This is primarily to prevent sewer gas from entering your house, and it does provide some protection against insects and small animals. But the condensate drain line from your HVAC unit is not required to have a P-trap. Personally, I would not want a P-trap on my condensate drain because I think it would be more likely to cause a clog than to prevent one. Most clogged drain issues in a house are caused by a stopped-up P-trap.

[EdFNJ]

Found these interesting tidbits:

Do I/you need a condensate drain trap if you have a condensate pump?
Yes, you need a condensate drain trap, even if you have a condensate pump. To repeat, the purpose of the condensate drain trap is usually to stop conditioned air from being blown outside. And this same logic applies if you have a condensate pump. However, without a trap, you will blow conditioned air into the pump, usually in the crawlspace, basement, or attic.

Are condensate drain traps required?
No code requires a condensate trap. However, IRC 1401.1 (we use the IRC here in Virginia) requires following the manufacturer’s instructions for installing “heating and cooling equipment and appliances.” You will be hard-pressed to find an AC installation manual that does not require condensate drain traps. Below is a diagram from a Carrier AC installation manual as an example. Notice that it requires installing a trap on both condensate drain lines.

Checked the manual from our just installed Carrier system and it does "require" one.

Copied from here: Your Air Conditioner Needs a Condensate Trap (https://www.ahouseonarock.com/not-having-a-condensate-drain-trap-is-like-leaving-a-window-open-with-the-ac-running/#:~:text=Yes%2C%20you%20need%20a%20condensate,air% 20from%20being%20blown%20outside)

[EdFNJ]

Your right except Amazon screen would be easier to clean. Won't those screens have more chance of getting clogged from the crud that often is drawn into the line from the condensate tray? Very often those lines get blocked, but not with animals. When they get blown out a lot "lint like" crud comes out.

[retiredguy123]

Found these interesting tidbits:

Do I/you need a condensate drain trap if you have a condensate pump?
Yes, you need a condensate drain trap, even if you have a condensate pump. To repeat, the purpose of the condensate drain trap is usually to stop conditioned air from being blown outside. And this same logic applies if you have a condensate pump. However, without a trap, you will blow conditioned air into the pump, usually in the crawlspace, basement, or attic.

Are condensate drain traps required?
No code requires a condensate trap. However, IRC 1401.1 (we use the IRC here in Virginia) requires following the manufacturer’s instructions for installing “heating and cooling equipment and appliances.” You will be hard-pressed to find an AC installation manual that does not require condensate drain traps. Below is a diagram from a Carrier AC installation manual as an example. Notice that it requires installing a trap on both condensate drain lines.

Checked the manual from our just installed Carrier system and it does "require" one.

Copied from here: Your Air Conditioner Needs a Condensate Trap (https://www.ahouseonarock.com/not-having-a-condensate-drain-trap-is-like-leaving-a-window-open-with-the-ac-running/#:~:text=Yes%2C%20you%20need%20a%20condensate,air% 20from%20being%20blown%20outside)
My Carrier HVAC system was installed by The Villages builder and it does not have a trap on the condensate drain line.

However, I did have a Carrier system in Virginia, and it had a trap on the condensate drain.

[retiredguy123]

. Won't those screens have more chance of getting clogged from the crud that often is drawn into the line from the condensate tray? Very often those lines get blocked, but not with animals. When they get blown out a lot "lint like" crud comes out.
I would be more concerned that the crud would clog up the condensate trap, if I had one. I think the loss of conditioned air is minimal. Personally, I don't plan to install either a condensate trap or a screen on the end of the pipe. As long as the drain continues to flow, I am happy.

[Bill14564]

My Carrier HVAC system was installed by The Villages builder and it does not have a trap on the condensate drain line.

However, I did have a Carrier system in Virginia, and it had a trap on the condensate drain.

My condensate line is one big trap. The line goes straight down from the unit, through the wall, then back up on the outside. Of course, the outside portion does not rise as high as the unit itself. Under normal conditions most of the line is full of water.

A short trap of some sort might help with the anoles. My line was blocked by one. The Amazon screen or even something simpler should also work for this particular problem.

[retiredguy123]

My condensate line is one big trap. The line goes straight down from the unit, through the wall, then back up on the outside. Of course, the outside portion does not rise as high as the unit itself. Under normal conditions most of the line is full of water.

A short trap of some sort might help with the anoles. My line was blocked by one. The Amazon screen or even something simpler should also work for this particular problem.
Note that, if your condensate drain is already trapped, adding another trap could result in double trapping.

"Double trapping causes drainage issues because air becomes trapped between the two traps, and air is lighter than water. That causes the air to travel up as the water flows down, resulting in no drainage."

[DAVES]

Part of my routine maintenance is to flush that line with vinegar. Doing that frequently will likely repel the pests, unless they like vinegar perfume.

You probably should check. In the past some have recommended vinegar, a mild acid and others bleach. Today they say plain water. I do ours once a month with plain water. So far 9years, no problem

[Bill14564]

You probably should check. In the past some have recommended vinegar, a mild acid and others bleach. Today they say plain water. I do ours once a month with plain water. So far 9years, no problem

Bleach *may* have an effect on the PVC and connections. Fumes from the vinegar or other acid *may* come back up the line and affect the aluminum condenser. It is probably debatable how significant either of those two concerns are but it's hard to imagine they would be recommended at all if they were high risk.

We use a gallon of hot tap water every month. No fumes and no mixing/measuring/dilution required. The volume *might* be enough to flush the lines and the temperature *might* be enough to kill any algae. If the gallon begins to back up then I know I have a problem starting and can take other measures to clean it out (nothing so far). I don't have nine years with this technique yet but so far so good.

[Michael G.]

You need to flush the condensate drain more than once a year. Once a month or so is needed. You don't need to use vinegar. A gallon of hot water will do just fine. That is what Munn's recommends.

After having a new HVAC Carrier system install in January, Munn's told me the same thing, hot water once a month.

No chemicals

[Rodneysblue]

My son called me today and said his AC quit working.
We got his shop vac out, jerry rigged a funnel with duct tape and sucked a died gecko out of the drain pipe.

Later he found one of these on Amazon.

Does anyone use them?

https://www.talkofthevillages.com/forums/attachments/villages-florida-general-discussion-73/99490d1690662116-screen-hvac-discharge-71lfulxzhsl-jpg

Cheers
Great idea! Also pouring hot water down the condensation drain helps prevent gummy buildup. Should do that once every couple of months.

[EdFNJ]

My Carrier HVAC system was installed by The Villages builders and it does not have a trap on the condensate drain line.

However, I did have a Carrier system in Virginia, and it had a trap on the condensate drain.. Our original one (2009) was installed by the Villages Builders (actually by SUN-KOOL) as well and it did have the trap out in the back yard next to the condensing unit. Shows how T.V. builders lack consistency, or maybe your original just got removed or broken. In any case, the manual from our 3 month old Carrier system says that CARRIER requires one and if it is like here as in that article from VA I linked **IF** local code says one is only needed **IF** A/C manufacturer requires it then those without one are in violation of code (not that it means a hill of beans just a POI). That article was about VA and I didn't look through code here as it really wasn't of importance, just a DP.

[retiredguy123]

. Our original one (2009) was installed by the Villages Builders (actually by SUN-KOOL) as well and it did have the trap out in the back yard next to the condensing unit. Shows how T.V. builders lack consistency, or maybe your original just got removed or broken. In any case, the manual from our 3 month old Carrier system says that CARRIER requires one and if it is like here as in that article from VA I linked **IF** local code says one is only needed **IF** A/C manufacturer requires it then those without one are in violation of code (not that it means a hill of beans just a POI). That article was about VA and I didn't look through code here as it really wasn't of importance, just a DP.
My neighborhood was built about 7 years ago. All of the houses have a Carrier HVAC system installed by Munn's. To my knowledge, none of them have a P-trap on the condensate drain line, either near the inside air handling unit or anywhere outside the house.

[Keefelane66]

My neighborhood was built about 7 years ago. All of the houses have a Carrier HVAC system installed by Munn's. To my knowledge, none of them have a P-trap on the condensate drain line, either near the inside air handling unit or anywhere outside the house.
“ Current IRC and Florida code (M1411. 3) does not require a p-trap in the condensate drain line.Sep 25, 2021”

[JGibson]

Flushing out condensate line with hot water and a drop of dish soap is the safer way to go. Once a month minimum.

[Maker]

To answer the original poster's question...
The screens in the picture are commonly installed on gas furnace air lines to prevent things from crawling into the pipes. They are not used on the condensate drain line. These pipes are air for combustion, and the exhaust. Currently, air pipes are 4" dia, but these look to be older, a smaller diameter.

DO NOT follow advice here to put in a P-trap, or flush these AIR LINES with anything.

The screens pictured are good because they have a much larger total surface area than the pipe cross section. Better screens will have openings in the screen that are a bit smaller, and larger overall screen surface area to reduce the pressure restriction that comes with adding a screen. These screens have a large volume of air moving through them.

Condensate lines are usually 3/4" or 1" diameter. If you can find a screen that diameter, and put it on condensate line, it may prevent some things from getting in. A gecko can squeeze thorough a very tiny opening. If you make a screen with tiny holes the size of window screens, it would likely plug up. I would not stretch a window screen across the opening of the PVC - that's asking for problems.
Any screen you add must be stainless steel.
Might want to look into this
hXXps://pvcventscreens.com/product/svc-is075/
https://pvcventscreens.com/product/svc-is075/

[retiredguy123]

If you are flushing the condensate line regularly and correctly, it is highly unlikely that an anole or any insect will be able to clog up the drain. A snake? Maybe. I have never used a screen on a condensate drain, and have never had a clogged condensate drain. So, I don't plan to do anything to correct a problem that doesn't exist. Clogged condensate drains are an issue that can shut down your HVAC system, but the usual cause is improper maintenance.

Note that the drain pan located under the evaporator coil has an electronic float switch that will shut off your HVAC system and prevent any water damage. I don't pay for regular HVAC maintenance, but if you do, I would suggest that you require the technician to test the float switch for proper operation.

[Michael G.]

I have never used a screen on a condensate drain, and have never had a clogged condensate drain. So, I don't plan to do anything to correct a problem that doesn't exist. Clogged condensate drains are an issue that can shut down your HVAC system, but the usual cause is improper maintenance.



After what Munn's told me to use hot water and reading the problems that a
screen can cause, or until I have a critter problem, I think I will just do my monthly maintenance.