Condensate drain line ideas (Heat Pump)

[Super38ACP]

I did not do this.

I have a heat pump, the air handler is in the garage. The air handler has a condensate pump which is connected to clear tubing and a check valve and routed through the concrete block wall along with the refrigerant lines.

With extended temperatures below freezing (not extremely common) this has the predictable result of freezing up to include the section within the concrete block.

There is no sink or drain in the garage.

Any ideas on how to set this up to prevent freezing up? My only real idea is to replace the last 6 or so feet with copper and stick a pipe heater on it, my thinking being that the copper will conduct enough heat to keep the section of pipe through the wall and outside from freezing up....

 

[Bucko]

If the drain pipe had a larger diameter with so the volume that was discharged would be much less than the pipe it may be enough to get you past the freeze. You could also put a tee in the line with a ball valve so in times of extreme cold you just bypass the exterior drain and run it into a bucket in the garage.

Around here the condensation lines are typically gravity based so no pump is needed but they need a P trap so the unit does not pull outside air into the unit and cause more condensation. It also helps to keep pests from using it as a highway.

 

[Gutman]

I might be wrong, but do you get any condensate when your heat pump is supplying heat?

Mine is bone dry, but I don't have a humidifier installed in mine.

 

[PoorUB]

Yes, no worries about the drain lines in heating mode.

 

[larry4406]

Agreed with others that for a heat pump, you will not be generating condensate while heating.

However, if your installation includes a humidifier, then you need a method to dispose of the condensate. If you have a humidifier, it could well drain to the condensate pump making your concerns valid.

 

[Super38ACP]

it must have a de-humidifier in it then because it has produced 2.5 or so gallons of water since 7 am... (because i pulled it through the wall, deiced it with a heat gun and stuck it in a 5 gallon homer bucket inside the garage...

It has got some sort of janitrol thing on it but we thought it was disconnected.

 

[metlmunchr]

Sounds like it has a humidifier with a problem. I'd find the water connection and turn it off. A lot of them are just connected to a nearby water line with a clamp on self tapping valve much like the ones automatic ice makers use.

 

[fitter30]

Poor ub is correct defrost mode is on the outside unit. No condensate from inside unit.

 

[justinjoyal]

Dehum in heating mode ? That's definitely not common (at least not where I'm from!)

Are you sure that's where the water is coming from ?

 

[mike93lx]

Is this a condensing natural gas or propane furnace? Guessing that is the condensate it is producing

 

[PoorUB]

it must have a de-humidifier in it then because it has produced 2.5 or so gallons of water since 7 am... (because i pulled it through the wall, deiced it with a heat gun and stuck it in a 5 gallon homer bucket inside the garage...

It has got some sort of janitrol thing on it but we thought it was disconnected.

Well, I assumed when you said air handler you had a heat pump and electric furnace. Do you have a gas furnace?

If you need to pump condensate outside I put this in a post for another situation. Runn a copper line outside up at a bout a 45 degree angle igh up on the wall, either cap the end and drill a few 1/32nd or 1/16th holes in the cap, Any bit of copper sticking outside should be insulated, but leave a foot or so inside exposed to absorb heat from inside. The copper should not freeze as tthe heat from inside will transfer out. Connect he condensate pump to the copper line. Also the water will drain back if you remove the check valve from the condensate pump. When the pump runs it will spray water out and it will freeze possibly before it hits the ground. A higher head condensate pump will spray the water harder and get a better mist.

 

[Super38ACP]

Well, I assumed when you said air handler you had a heat pump and electric furnace. Do you have a gas furnace?

Well this is embarrassing - yes but it was my understanding that it was only used as auxiliary heat. Like heat strips. The heat pump outside unit is definitely running.

Also I should have specified that it is the unit that heats the house not the garage, the garage it is in is unheated/cooled

The condensate pump is wired so the if it cannot discharge the water (such as when the line freezes) it cuts the whole unit off (aux and standard heat or AC.

The garage has stayed above freezing even with the outside at 4 and 5, so i suppose there might be enough heat in there to keep the copper from freezing without the pipe heater.

I'll try to grab a few pictures of the unit later today, maybe y'all can see some thing not obvious to me.

Our old house just had a regular heat pump with heat strips so i'm a little confused by this whole set up.

 

[FullRaceMerc]

I live in a warm climate, so outdoor freezing isn't common here. But I worked on walk-in freezers for a couple of years. With those we tried some different methods.

Eventually we decided that the best solution was to wrap heat tape & insulate everything that was exposed to cold. And to wire the heat tape to be always on, since we were always dealing with sub freezing temps.

Expecting warmed water to be warm enough to flow thru cold portions was a failure, as was expecting the heat tape to do its job if run only during the defrost cycle. We replaced frozen & split copper pipe following those attempts.

On your application I'd be tempted to drill out the wall to provide enough room for pipe, heat, & insulation. And run the heat all the way to the outlet. Then set up a thermostat that measures the outdoor temp to turn on the drain heat system anytime it gets near freezing.

 

[Wiz02]

I just experienced an issue with the condensate drain line right before the cold snap. The condensing gas furnace wouldn't run. Tstat called for heat, relays clicked and that was it. HVAC guy tracked the problem down to a blocked 3/4 inch pvc drain line. The condensate line runs into the sump pump pit, gravity only, no pump. The pvc was completely gunked up. Once we ran some air through it, furnace started working. He did reroute the humidifier drain to be a separate line going to the sump instead of teeing into the furnace condensate drain.

I mention this because even if you think the drain line is much larger than the trickle of discharge from the condensing furnace, it may be partially or almost all blocked up and so become more susceptible to freezing.

 

[mike93lx]

I just experienced an issue with the condensate drain line right before the cold snap. The condensing gas furnace wouldn't run. Tstat called for heat, relays clicked and that was it. HVAC guy tracked the problem down to a blocked 3/4 inch pvc drain line. The condensate line runs into the sump pump pit, gravity only, no pump. The pvc was completely gunked up. Once we ran some air through it, furnace started working. He did reroute the humidifier drain to be a separate line going to the sump instead of teeing into the furnace condensate drain.

I mention this because even if you think the drain line is much larger than the trickle of discharge from the condensing furnace, it may be partially or almost all blocked up and so become more susceptible to freezing.

I spent the morning on a buddy's furnace dealing with a 3/4 drain line that was frozen solid. After thawing it, replacing a cracked section and adding a union, we heat taped and insulated it. It's not worth running it 24/7 here, so hopefully he remembers to plug it in when it gets really cold

 

[Super38ACP]

The unit



There is a pipe tap above the unit that is no longer attached to anything (that’s probably a recipe for a flooded garage)…

 

[larry4406]

You have a 90+% gas furnace, not a heat pump.

It generates condensate when burning.

It generates condensate as an AC as well.

Combustible appliances in a garage, typically are mounted 18"(??) above the walk surface so that it won't ignite gas fumes from the garage.

Your unit is also pulling combustion air from the garage space, not outside.

 

[mike93lx]

You have a 90+% gas furnace, not a heat pump.

It generates condensate when burning.

It generates condensate as an AC as well.

Combustible appliances in a garage, typically are mounted 18"(??) above the walk surface so that it won't ignite gas fumes from the garage.

Your unit is also pulling combustion air from the garage space, not outside.

How can you say he doesn't also have a heat pump from those pics?

 

[larry4406]

How can you say he doesn't also have a heat pump from those pics?

Fair statement.

If he has a dual fuel setup, then it could look just like this yet be a heat pump as well.

If it is a dual fuel unit, and operating as a heat pump, then his condensate is from the humidifier. Alternately, if it is operating as a condensing furnace (ie furnace taking over), then the condensate is coming from both the furnace and the humidifier.

 

[mike93lx]

Fair statement.

If he has a dual fuel setup, then it could look just like this yet be a heat pump as well.

If it is a dual fuel unit, and operating as a heat pump, then his condensate is from the humidifier. Alternately, if it is operating as a condensing furnace (ie furnace taking over), then the condensate is coming from both the furnace and the humidifier.

I am going to guess that maybe the outside unit was running and it either couldn't keep up or switched to the furnace for a defrost cycle, making it look like the heat pump was still generating but condensate was being produced.

All speculation though, just thinking about possibilities

 

[Super38ACP]

The outside unit is a Concord (Lennox/ Armstrong ) 4HP14L48P-2A which is a heat pump from what I can find.

I believe the gas furnace portion here is for auxiliary heat. It’s fairly apparent when it comes on as it feels warm- which the heat pump never does and my gas bill is not enough for the furnace to be the exclusive heat source.

I suppose I have my strategy here with a length of copper tube for the condensation line.

Oh and yes its been very cold latelyI believe the last time it was above freezing was Friday midday. It was 4 when the line froze. We woke up to 60 degrees inside so it froze sometime early morning. Since i routed the line into the bucket in the garage its remained able to keep the house warm (67 or so). It takes it over 24 hours to produce a full 5 gallon bucket.

I'm reasonably sure there is no working humidifier/de-humidifier.

 

[Super38ACP]

So with the last few days increased temps the amount of condensate has decreased markedly.

Dual fuel - y'all mean gas and electric?

 

[larry4406]

So with the last few days increased temps the amount of condensate has decreased markedly.

Dual fuel - y'all mean gas and electric?

Yes - a dual fuel setup means you have a heat pump without electric resistance heat backup. The heat pump provides your heating and cooling under "normal" outdoor temperatures.

With a dual fuel setup, if the outdoor temperatures become "too cold", instead of the heat pump kicking in electric resistance heat, it instead kicks on a gas furnace.