Is Water Accumulation in My HVAC Condenser Causing Operational Issues?

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Discussion Overview

The discussion revolves around the operational issues of an HVAC system, specifically concerning water accumulation in the condenser unit and its potential impact on functionality. Participants explore the mechanics of condensate management, the role of pumps, and the implications of a multi-home HVAC system.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant describes their HVAC system, noting a small electric motor and a water reservoir that has not been emptied for nearly a decade, raising concerns about its current functionality.
  • Another participant suggests that the motor likely operates a pump to remove condensate, indicating that if the pump fails, it could lead to overflow, but does not believe this would prevent the unit from starting.
  • A participant elaborates on the components of a split system A/C unit, explaining the roles of the condensing unit and air handling unit, and suggests that the A/C issues may be related to the fan or thermostat rather than the condensate system.
  • There is a discussion about the nature of the HVAC system, with one participant confirming it is a chilled water system and asking for more details about the connected pipes.
  • Concerns are raised about the potential for blockages in the condensate lines, with one participant sharing a personal experience of a similar issue leading to a mess due to growth in the condensate container.
  • Several participants mention the presence of overflow switches in A/C units that could prevent operation if water levels exceed a certain point, indicating a safety mechanism that might be relevant to the current problem.

Areas of Agreement / Disagreement

Participants express varying opinions on the cause of the A/C issues, with some attributing it to the condensate system and others suggesting it may be unrelated. There is no consensus on the exact cause of the operational problems.

Contextual Notes

Participants note the complexity of the HVAC system, including the potential for multiple components to influence performance. There are references to specific system configurations, such as chilled water systems versus refrigerant-based systems, which may affect the discussion's applicability to different setups.

Who May Find This Useful

This discussion may be useful for homeowners or tenants experiencing similar HVAC issues, maintenance personnel, and individuals interested in the technical workings of HVAC systems and condensate management.

EnumaElish
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The heater/cooling system (HVAC) at home has a condenser unit. It's a small electric motor sitting atop a shoebox-sized metal container which holds the water dripping from the "fan unit" (I don't have a better technical term to describe the main unit that houses the fan). There is also a thin hose that rises from the water box and goes into the ceiling, I have no idea where, or why.

My question is: do I need to empty the water accumulating inside the box? I never emptied it for almost 10 years, and it did not present a problem. Lately, the A/C has stopped working and has been difficult to restart, and I'm guessing that the reason has something to do with the condenser.

FWIW, the HVAC is part of a multi-home system -- there is a "plant" somewhere that needs to be operating for the HVAC to work.
 
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There is also a thin hose that rises from the water box and goes into the ceiling, I have no idea where, or why.
The motor on the box/reservoir is probably for running a pump to remove the condensate. It probably goes to a drain. If the pump stops working, you would start to see the reservoir overflowing. I don't believe this problem would cause the unit to not start however.
 
EnumaElish said:
The heater/cooling system (HVAC) at home has a condenser unit. It's a small electric motor sitting atop a shoebox-sized metal container which holds the water dripping from the "fan unit" (I don't have a better technical term to describe the main unit that houses the fan). There is also a thin hose that rises from the water box and goes into the ceiling, I have no idea where, or why.

My question is: do I need to empty the water accumulating inside the box? I never emptied it for almost 10 years, and it did not present a problem.
Oy.

A split system home a/c unit consists of two parts:

The condensing unit is a (usually) cylindrical heat exchanger with a fan at the top and a compressor to compress the refrigerant.

The air handling unit is the box with a fan that sits inside your house and circulates air through your house. It contains an evaporator coil, which is where the refrigerant cools the air by evaporating from a cold liquid to a warm gas.

When the evaporator cools the air, some water will condense out of the air. The evaporator contains a drain pan which is connected to a drain hose and drains this condensate from the drain pan where it goes to a shoebox-sized pump mounted to the side of the air handling unit. When the tank on the pump fills, the pump pumps the condensate to the nearest drain.

So no, what you are describing is a condensate pump with a tank on it and it will empty itself periodically as long as it isn't broken.

http://www.plumbersurplus.com/Cat/Condensate-Pumps/284/List
Lately, the A/C has stopped working and has been difficult to restart, and I'm guessing that the reason has something to do with the condenser.
That's more likely a fan or thermostat problem, but if you live in an apartment building and don't own your system, it isn't your problem anyway: just call your management office and they'll fix it.
FWIW, the HVAC is part of a multi-home system -- there is a "plant" somewhere that needs to be operating for the HVAC to work.
Do you live in a large apartment building? If so, there may be a chilled water plant on the roof, in which case my description above is off a bit. In which case the parts/heat flow are:

Cooling tower makes cool water to cool the condenser in the chiller.
Chiller contains the evaporator and condenser and makes cold water.
Air handling unit (aka "fan coil unit") in your apartment that passes the cold water through a heat exchanger to make cold air.

It would be pretty unusual for you to own your fan coil unit if you live in an apartment building with a central chilled/hot water plant.

Could you answer these two questions, please:
The air handling unit or coil that makes the cold air has two pipes (and one nylon tube, probably) connected to it. Are they the same size or is one larger than the other?
See if you can find a sticker on your a/c unit with a model number or name. Could you tell me what they are?
 
Last edited by a moderator:
Thanks, dlgoff!

Thanks, russ!
russ_watters said:
It would be pretty unusual for you to own your fan coil unit
You're right, I don't.

The air handling unit or coil that makes the cold air has two pipes (and one nylon tube, probably) connected to it. Are they the same size or is one larger than the other?
They are the same size.
See if you can find a sticker on your a/c unit with a model number or name. Could you tell me what they are?
"FHP," manufactured by Harrow Products, "SE032-1."

[quotes fixed - russ]
 
Last edited by a moderator:
Ok, does sound like a chilled water system/fan coil unit - so it's the second system I described. In a refrigerant based system, the two pipes are different sizes because one contains a liquid and the other a gas.

I've never heard of that manufacturer and don't get any hits on a google. So at this point, if you're having problems, just call your maintenance/management service.
 
dlgoff said:
The motor on the box/reservoir is probably for running a pump to remove the condensate. It probably goes to a drain. If the pump stops working, you would start to see the reservoir overflowing. I don't believe this problem would cause the unit to not start however.

Most A/C units that utilize a condensate pump have an overflow switch. The switch will open the control circuit to the A/C if the water in the condensate container gets above a predetermined point.

I had a big mess with one of these things a few years back. It turned out that all kinds of yucky junk was growing in the condensate container and lines blocking the flow.

EnumaElish:

If you have free maintenance service by all means call them. Sometimes the condensate pumps plug into an electrical outlet near the unit. Is it plugged in?
 
edward said:
Most A/C units that utilize a condensate pump have an overflow switch. The switch will open the control circuit to the A/C if the water in the condensate container gets above a predetermined point.
That's a good point. The drain pan in the fan coil unit may also have a high-limit switch. But...
I had a big mess with one of these things a few years back. It turned out that all kinds of yucky junk was growing in the condensate container and lines blocking the flow.
...the drain pan of my department's air conditioner at work did not have a high limit switch. Woulda been nice when the condensate piping got clogged with yucky junk a few weeks ago...
 
Yea, Mine either. Once I wished it had. There's a gravity drain line in the bottom of my ACs tray. Yep, it clogged up. Since the it's is in a closet area, it got really wet before I discovered it.
 
It shouldn't be too hard to look in the drain pan and see if there is a level switch (and if the condensate has accumulated to the level of the switch).
 

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