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-   -   Can/should I plug this hole? (http://www.diychatroom.com/f17/can-should-i-plug-hole-155226/)

Hogan773 08-29-2012 03:21 PM

Can/should I plug this hole?
 
On both my AC units there is a threaded "drain hole" that is just open....it is a sister to a similar hole that has PVC pipe coming out and is where water drains out. There is a pretty healthy rush of cold air coming out of the hole when the A/C is on.

OK to plug up or tape over the hole? Or does it need to stay open for some reason? I'm always uncertain about suction requirements or vacuum issues or pressures or whatever. Not as big a deal in my basement since that is finished living space so I am just cooling my utility room, but for my attic unit I am just blasting nice cool A/C air into my unfinished attic which is a pure loss.

There is a red plastic "cap" lying on the ground there that seems to fit into the hole.....although it doesn't stop the air from coming out.


https://lh4.googleusercontent.com/-2...25280%2529.jpg

NitroNate 08-29-2012 03:41 PM

that is the overflow hole, so provided there is a secondary pan under it (which there should be), no, it needs to stay open.

Hogan773 08-29-2012 03:56 PM

Quote:

Originally Posted by NitroNate (Post 999211)
that is the overflow hole, so provided there is a secondary pan under it (which there should be), no, it needs to stay open.

Yep there is a pan under the whole unit for my attic HVAC (which is the one in the picture). In my basement I think it would "overflow" down the side of the unit, but there may be a small pan I'm forgetting.

Just curious, why does there need to be an overflow hole.....how would the primary PVC fail to handle the trickle of condensation that comes out? Seems like a waste of air conditioned air to have it just blowing out the side 24/7........

NitroNate 08-29-2012 04:10 PM

secondary pan and overflow outlet handles a situation when the main drain clogs. this actually happens more often than you'd think. it can happen for a variety of reasons, but the condensation pvc line isn't very big so it clogs up easier.

Doc Holliday 08-29-2012 04:18 PM

Put a float switch in the secondary hole. If water backs up due to a main drain clog water will build up into the switch which protrudes from the now vacant secondary hole and the switch which then cuts off either power to the stat or more usually the condenser, however it may be wired in. Without the condenser running no more condensation can accumulate. Now you know you have a problem (as the system will blow warm air without the condenser running) without resulting in any water damage.

The one on the right.

http://fierychill.com/media/catalog/...t/gt-ss1-2.jpg

Hogan773 08-29-2012 04:26 PM

Quote:

Originally Posted by Doc Holliday (Post 999238)
Put a float switch in the secondary hole. If water backs up due to a main drain clog water will build up into the switch which protrudes from the now vacant secondary hole and the switch which then cuts off either power to the stat or more usually the condenser, however it may be wired in. Without the condenser running no more condensation can accumulate. Now you know you have a problem (as the system will blow warm air without the condenser running) without resulting in any water damage.

The one on the right.

http://fierychill.com/media/catalog/...t/gt-ss1-2.jpg

Hmmmm...is the one on the right completely closed ie it won't vent air? I'm guessing my cost of "efficiency lost" isn't that large so depending on the cost of the switch it might not be worth the price.

Doc Holliday 08-29-2012 04:34 PM

That switch shouldn't cost you any more than $20. The threaded piece is entirely separate from the other piece. You simply screw in the threaded male fitting and then dry fit by pushing the "L" shaped switch onto the fitting. The top, where the wires are, pulls off so you can see in there if you ever need to as well as clean the drain if ever needed.

The two switch wires simply break one of the two wires to the condenser. Literally, cut one wire to the condenser and attach each wire from the switch to each side of the now cut wire. Now power is going through that switch.

If you do do this, turn the BREAKER to the furnace off before cutting any wire, not just turn the stat off. The BREAKER off.

Good luck.

Hogan773 08-29-2012 04:36 PM

As an aside, I also felt lots of air coming out of this square hole on my humidifier. There was a metal placard just snapped into the hole with the name of the mfr on it, but it wasn't airtight at all. I took out the placard and sealed with some foil tape. It seems the humidifier basically takes off return air into a pipe, runs it past the wet filter and then mixes it back into the newly cooled air as it's exiting the system toward the ducts.


https://lh5.googleusercontent.com/-f...828_235519.jpg

Hogan773 08-29-2012 04:38 PM

Quote:

Originally Posted by Doc Holliday (Post 999246)
That switch shouldn't cost you any more than $20. The threaded piece is entirely separate from the other piece. You simply screw in the threaded male fitting and then dry fit by pushing the "L" shaped switch onto the fitting. The top, where the wires are, pulls off so you can see in there if you ever need to as well as clean the drain if ever needed.

The two switch wires simply break one of the two wires to the condenser. Literally, cut one wire to the condenser and attach each wire from the switch to each side of the now cut wire. Now power is going through that switch.

If you do do this, turn the BREAKER to the furnace off before cutting any wire, not just turn the stat off. The BREAKER off.

Good luck.

Sounds like this might be "too much fun" in search of plugging a small hole......

techpappy 08-31-2012 12:04 PM

That is not a "wet filter". It is the evaporator pad that helps to vaporize water to provide humidification to the air stream during heating mode. It was OK to plug the hole you found though as it isn't necessary. Just an apparent leak.

DO NOT RUN HUMIDIFIER DURING COOLING SEASON!!

Hogan773 08-31-2012 01:48 PM

Quote:

Originally Posted by techpappy (Post 1000491)
That is not a "wet filter". It is the evaporator pad that helps to vaporize water to provide humidification to the air stream during heating mode. It was OK to plug the hole you found though as it isn't necessary. Just an apparent leak.

DO NOT RUN HUMIDIFIER DURING COOLING SEASON!!

My auditor suggested that I may want to just turn off the humidifier all the way, which I've done. Like many homeowners I assume, I was lax about switching settings between seasons. This winter I am going to see how dry it gets in the house (I have a digital thermometer that also has a humidistat) as the auditor's view was that in a tighter house, just normal occupancy, showers, baths, etc would create enough humidity. We shall see I guess.

Hogan773 09-07-2012 01:14 PM

I have another question on the condensate draining (see original picture below with drain holes)
https://lh4.googleusercontent.com/-2...25280%2529.jpg
My primary drain, with the PVC pipe attached "kind of" drains out but there is also some puddles of water sitting in my secondary drain pan. When I looked closely there was some water sort of blowing out of the overflow hole. There is NOT a clog in the PVC pipe (I took it off to check) so please don't just tell me to pour bleach in the pipe. It's not an algae blockage in the pipe. What it seems is that the primary drain pipe is flat level or even inclined a bit. It seems the black "sockets" for those drains aren't tilted downward. If I push hard down on the pipe and sockets, I get a little better flow out.

Also, when I shine a light in there, there is a layer of water inside the pan....not super deep but is that normal? I thought that maybe the pan should be more aggressively sloped so that any water has a real positive drain out into the PVC pipe. Right now it sort of finds its way there slowly and the blowing air helps it. But it sort of has to make it over the "lip" of the PVC pipe that is screwed into the drain, and then it has to flow on a flat surface around the corner until the PVC pipe starts sloping down.

Is this NORMAL or is there some way to fix it?

Thanks in advance

HVACDave 09-07-2012 01:30 PM

Best way would be to make a trap on the drain outlet with 3-90 degree elbows and then a tee, then out your drain pipe.(be sure the tee exits at a lower level than your height out of the drain pan obviously) This then keeps the condensate from being affected by the pressure of the air in your ductwork.

You can do the same thing with your secondary drain hole and then fill the trap with water and no more air will leak out. If you are concerned that the water will evaporate out and you will have the same problem down the road then put a little vegtable oil on top of the water in the trap and then it won't evaporate.

Hogan773 09-07-2012 03:42 PM

Quote:

Originally Posted by HVACDave (Post 1005064)
Best way would be to make a trap on the drain outlet with 3-90 degree elbows and then a tee, then out your drain pipe.(be sure the tee exits at a lower level than your height out of the drain pan obviously) This then keeps the condensate from being affected by the pressure of the air in your ductwork.

You can do the same thing with your secondary drain hole and then fill the trap with water and no more air will leak out. If you are concerned that the water will evaporate out and you will have the same problem down the road then put a little vegtable oil on top of the water in the trap and then it won't evaporate.

Hmmm interesting....maybe I don't follow you though. Putting a p-trap on the main drain does what....keeps the air from blowing into the drain? It almost seemed as if the air was helping to blow the water into the drain although I can't be sure.

Is it normal for there to be a full layer of water in the drain pan at all times? It seems like the drain hole is not really the LOWEST point in the drain pan so I guess there has to be some water. I didn't know if I'm supposed to jack up the unit on one side so it is at more of an angle for the water to run to the drain.

digitalplumber 09-07-2012 03:59 PM

Quote:

Originally Posted by Hogan773

Hmmm interesting....maybe I don't follow you though. Putting a p-trap on the main drain does what....keeps the air from blowing into the drain? It almost seemed as if the air was helping to blow the water into the drain although I can't be sure.

Is it normal for there to be a full layer of water in the drain pan at all times? It seems like the drain hole is not really the LOWEST point in the drain pan so I guess there has to be some water. I didn't know if I'm supposed to jack up the unit on one side so it is at more of an angle for the water to run to the drain.

Which drain pan? The secondary? No, that would mean you have an issue.


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