Heat Tape for Condensate Drain Lines

[benjamming]

So, our gas furnace condensate lines froze this last week and ending up draining into our dining room. Fortunately, we were home & caught it rather quickly so no damage to the living quarters except paint & drywall. The fiberglass insulation in the attic got wet, of course.

One failed part of the system was that hose clamps weren't used when the vinyl condensate line from the gas furnace & the vinyl condensate line from the coil (split system heat pump) tee. Fixed that easily with new SST Trident hose clamps.

Another failed part was that the aluminum drain pan under the horizontal furnace leaked at a corner once half full. I pumped out ~ 5-gal to stop leaking & give some comfort.

Several questions:

Should the fiberglass insulation be replaced or left to dry? Not much of it got wet, it appears at least.

The ceiling in the dining room will have to be repainted as there were one pretty large water bubble. Amazing how much paint will stretch. Anyway, should the drywall be replaced in affected areas?

The York manual recommends heat tape be used for installations where it may freeze (evidently, in my attic in Alabama every 3 years - no problem last two winters). It says to use uL listed, 3W/ft @ 115VAC, 40°F self-regulating, shielded, & waterproof, made in USA. Ok, I added the last part. Another page in the manual says to use 3-6 W/ft heat tape. Easy Heat is one of many (I imagine) heat tape manufacturers. However, these guys only go down to 1/2" with the PSR & my soft vinyl tubing is 3/8" ID. They don't recommend their PSR or Freeze Free with soft vinyl anyway. Their Freeze Free is only rated for up to 150°F & I imagine it will be hotter than that in the attic during summer. Any other mfg that would be recommended?

We will cover the heat tape with Armaflex or some other heat resistant insulation material. What thickness should be used - 1/2"?

 

[Dan55]

Can you change the soft vinyl to a copper drain,and how many feet do you have to run? Nelson and Thermon also Raychem make Heat Trace and the stuff is not cheap. I ran about 2000' of the cable in the last month and a half, just finished on friday.

 

[Dan55]

I read the info on Easy Heat it should be perfect for you,but your going to change that vinyl hose.

 

[benjamming]

I was hoping to not have to change the vinyl hose. Are there any heat tape mfg that will recommend it for soft vinyl? In addition, the smallest diameter pipe that I see for heat tape applications is 1/2". I guess adapting from 3/8" hose barb to 1/2" pipe will be necessary. The 3/8 hose barb has an integral check valve on each pump so I don't want to change that.

If (or when) the tubing is changed, Schedule 40 PVC would be my 1st choice. Copper would be a lot more expensive w/o any significant advantages unless someone can educate me. Total drain hose run is probably 50' so 75' of heat tape will be close.

How hot does an attic get in the south?

Price estimate for the heat tape - 100' roll?

I already have a 120V spare outlet in the attic which was run in case a radon fan was ever needed. The 2nd radon test was very low so I should be able to use that outlet.

On a related note, who should pay for all the repair work of the drywall/insulation/paint & the new heat tape installation? My thought is that the HVAC installer should have to pay for the repairs. I would then pay for the heat tape installation since this doesn't seem to be a common (read: never) installation practice in my area so it wasn't figured into the original installation price (3 year old new construction house). Thoughts?

 

[Gary Allan]

Use heater hose ..adapt easily, leaving your check-valved barb intact ..able to take your heat trace ..and totally fishable anywhere you need ..cheaper than most flexible alternatives of such durability ..good for (probably) many decades of zero pressure and less than 212F to -whatever F on a daily basis.

 

[eljefino]

Your furnace is in your attic? Crazy.

Maybe the hose clamps were left off as a path of least resistance, if a freezeup were to occur the line would blow off, "saving" the furnace.

 

[benjamming]

eljefino,

Why is it crazy to have a furnace in the attic? My air registers aren't in the floor as I live in a cooling climate.

I take it that your last comment was tongue-in-cheek but if not, then the condensate lines would simply overflow the 1-qt reservoir of the float-actuated pump while dead-heading & the condensate would flow into the drain pan which is what it did.

Gary,

Heater hose is not something that I had thought about. What material - EPDM, silicone? The water can be acidic so that must be accounted for. Goodyear Red Heater Hose EPDM 65017 & Goodyear Silicone Heater Hose 65039 are both 3/8" ID so no adapters needed. Unfortunately, special hose clamps are required for the silicone hose. However, they both says to not use for oil transfer applications. There can be oil in the condensate from the heat pump split system condensate line (R410A system).

Goodyear Service Station Air Hose 65137 is EPDM with working pressure of 250 psi, 3/8" ID, & no warning about oil, etc.

The attic doesn't have any skylights so no UV concern.

 

[Dan55]

Check this out http://www.easyheat.com/Content1/PDF_Files/_files/40200_001_r4_AHB_appguide_web.pdf

 

[Gary Allan]

Quote:
Heater hose is not something that I had thought about. What material - EPDM, silicone? The water can be acidic so that must be accounted for.




EPDM isn't suitable for oil

..but in the interest of our highly coveted peace of mind, and one time "set it and forget it" confidence, 1/2" trans line would be overkill.


Quote:
are both 3/8" ID so no adapters needed.


Yes, but by adapting bigger, if I read your initial post correctly, you would solve your heat trace challenge due to too small a diameter. I probably missed some intermediate solution in there.

 

[benjamming]

Gary,

Goodyear 65137 Air Station Hose is EPDM & listed as good for oil (RMA Class C oil resistance). Class C Oil Resistance loosely defined I would consider that Fair, not Good or Excellent which is what I want when selecting materials of construction. I thought that I had found an anomaly but it was not to be. Yep, move on away from EPDM.

Gary,

You didn't miss any intermediate solution to the size issue. I was hoping to find heat tape that would work with sizes < 1/2" which Dan55 found one example it appears.

 

[tmorris1]

You can get pipe or tube that won't burst, but you are still going to have a mess with backed up water when it freezes.
You need to get a pump with a shutoff switch to the furnace. If the pump quits or get backed up it will shutdown the furnace. Then you will save your ceiling and know that there is a problem. Whatever the cost of heat tape, it is better than replacing drywall and insulation. You would only have to use the heat tape on cold days.

 

[benjamming]

tmorris,

What pipe or tube would you recommend that doesn't burst?

The heat tape is self-regulating 40°F so it will protect against freezing only when needed. If the heat tape fails, the pump dead-heads, & we now know to listen for that in the dining room (it's very obvious once you know). We never thought about the lines freezing previously. But you do bring up a good point for the case to use maybe a power monitor on the pump & connect to the furnace as a 3rd defense against failure. The pump only runs for ~ 10-20 seconds at a time so it is off most of the time. Yeah, I'm not worried about the cost of heat tape or the electricty to operate. I mean just think if this would have happened when we were on vacation for a week. A lot more than a sheet of drywall & a couple rolls of insulation would have been lost - wood floor, chairs, table, etc.

BTW, the drywall area that is damaged appears to only be ~ 4'x8'.

 

[labman]

I thought the heater hose sounded like a good idea. Pex also stands freezing.

Could you run straight up from the pump and then leave a slanting line that would drain itself?

 

[tmorris1]

Originally Posted By: benjamming
tmorris,

What pipe or tube would you recommend that doesn't burst?

The heat tape is self-regulating 40°F so it will protect against freezing only when needed. If the heat tape fails, the pump dead-heads, & we now know to listen for that in the dining room (it's very obvious once you know). We never thought about the lines freezing previously. But you do bring up a good point for the case to use maybe a power monitor on the pump & connect to the furnace as a 3rd defense against failure. The pump only runs for ~ 10-20 seconds at a time so it is off most of the time. Yeah, I'm not worried about the cost of heat tape or the electricty to operate. I mean just think if this would have happened when we were on vacation for a week. A lot more than a sheet of drywall & a couple rolls of insulation would have been lost - wood floor, chairs, table, etc.

BTW, the drywall area that is damaged appears to only be ~ 4'x8'.

I don't know what would not burst. My point was that if it is freezing up you will still have a water problem whether it bursts or not. The water will backup and run out of the pump or damage the furnace and/or your ceiling. They make pumps with safety switches (I think they can be added to existing pumps too) that will shutoff your furnace or A/C and possible sound and alarm if it becomes clogged.

 

[benjamming]

labman,

I can't run it that way but did as much as possible.

Would double wall containment pipe be a good option here? Asahi America Double Containment Piping Systems is one that I found.

 

[labman]

Severe weather is often accompanied by power outages. That double wall would be a real belt and suspenders thing.

My next project is converting my generator to run on gasoline, propane, or natural gas. It is easy to transfer gas from my truck to the generator. Which is fine until the power if off, the tank empty, and we are snowed in. I sort of feel if that never happens, money well spent, just like fire insurance.

 

[benjamming]

I have a 16kW propane generator that will run the heat & accessories so no problem there.

 

[tmorris1]

Originally Posted By: benjamming
I have a 16kW propane generator that will run the heat & accessories so no problem there.

Man, you are ready for the apocalypse...

 

[benjamming]

Apocalypse itself, yes. Events leading up to it, no one can be fully prepared for that.

Anyway, I am looking at Tyco, Thermon, & Nelson Limitrace. Supposedly, you can buy the whole shooting match - stainless steel tube (seamless or welded) with heat trace & insulation factory installed & all that is left is landing the electrical & connecting to the inlet/outlet. I'm sure that costs a mint though.

Any comment on who should pay for the heat trace & the repairs to the drywall, paint, & insulation since the installation was botched & didn't follow the York manual?

 

[tmorris1]

Originally Posted By: benjamming

Any comment on who should pay for the heat trace & the repairs to the drywall, paint, & insulation since the installation was botched & didn't follow the York manual?


I think the installer should pay for it, but in reality I think you will get stuck with it. Nobody will admit a mistake anymore for fear of being sued.