Thread: A/C Condensate Drain Line Insulation

I could have sworn I read it somewhere, but can't find it. Maybe it was a dream. I thought there was a code that said A/C condensate drain lines had to be insulated for 6' coming out of the unit. Does anyone have any information they can share?

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I have been a HI for about 27 years and I don't think I have ever seen one insulated.

It is not a code.

Originally Posted by Gene South

It is not a code.

I don't think it's a residential code, either (check your municipality).
But it's a very common commercial specification that condensate lines shall be insulated. Especially down here in high humidity areas like mine.

I wouldn't be scared to make a 'recommendation' as a maintenance item on my report.

I always recommend insulating the primary condensate line based on experience. A hot attic plus cold condensate = condensation. Around here most hvac guys insulate the horizontal sections. There are some codes that seem to allude to this.

M 1412.3,- Refrigerant piping, brine piping and fittings within a building shall be insulated to prevent condensation from forming on piping.
N1103.3 - Mechanical system piping capable of carrying fluids above 105°F (40°C) or below 55°F (13°C) shall be insulated to a minimum of R-3.
and
503.2.8 from the energy code- All piping serving as part of a heating or cooling system shall be thermally insulated in accordance with Table 503.2.8.

I've seen a lot of under floor condensate lines with condensation dripping from them because of the lack of insulation and high humidity.

Originally Posted by Wade Hancock

I don't think it's a residential code, either (check your municipality).
But it's a very common commercial specification that condensate lines shall be insulated. Especially down here in high humidity areas like mine.

I wouldn't be scared to make a 'recommendation' as a maintenance item on my report.

I have seen it required in commercial installations in NJ.

Well, thanks for the replies everyone. I don't know where I got it from.

Not required in the Carolina's

Andrew Constantine
InspectPro Home Inspections
Charlotte NC Home Inspector

Originally Posted by Kris Svendsen

I could have sworn I read it somewhere, but can't find it. Maybe it was a dream. I thought there was a code that said A/C condensate drain lines had to be insulated for 6' coming out of the unit. Does anyone have any information they can share?

It is not a bad idea, especially if you have a split system and the coil is in the attic. If you see signs of the condensation dripping outside the pan, I would recommend it. I have seen wet spots/stains on ceilings from condensation dripping.

As for a requirement, I do not know of one but as we all know the codes are the minimal requirement. It never hurts to exceed the minimum if it helps to improve something!

I never see dripping on primaries when the line pitch is excessive and has no trap. I often see dripping and water stains on the attic floor when there is a trap with no insulation. So I call out for trap insulation. At least once have I seen the trap located over the pan.

Speaking of line insulation, here is something interesting about refrigerant line insulation that I have never seen in the field.

"Normally, no insulation is used on the liquid line because the liquid line is usually warmer than its surroundings. Allowing the liquid line to lose heat to the air actually improves performance by increasing subcooing. However, when the liquid line runs through a hot space such as an attic, insulation of the liqud line may be required to prevent boiling from occurring prior to the expansion valve.

Insulation on the liquid line of a computer room air conditioning system is desirable. The liquid can get quite cold in winter and lines running through humidified space to the air conditioning unit will sweat and drip if not covered.

Sometimes the liquid line can be insulated together with the suction line to promote heat exchange betwen the two lines for long line applications. The extra subcoooling the liquid line receives from the suction line helps to prevent flash gas in the liquid line." (AHRI: Fundamentals of HVAC/R)

I have also seen sections of rubber insulation on heat pump suction lines that had been melted close to the evaporator. Here is why:

"Some types of insulation that are acceptable for suction line insulation are not able to withstand the high temperatures of the gas line on a heat pump when it is operating in heat. Generally speaking, lines on heat pumps are usually insulated with elastomeric rubber insuation: polyolefin insulation materials is not used for heat pumps. Make sure that insulation used on the large gas line of a heat pum system is rated for heat pump duty. (ditto).

Kris,
I'm guessing you heard it from an old inspector or Instructor that was doing these 10 years ago. The 2000 Texas SOP says this
(8) report as in need of repair the lack of insulation on
refrigerant pipes and the primary condensate drain pipe

That's where it came from. It was a hard thing to write up since every HVAC professional told the clients we didn't know what we were talking about.

Welcome to the profession.

You're probably right Gary. It was probably a combination of the SOP and instructors. All my instructor were in the 4000 license number or below.

Originally Posted by Kris Svendsen

You're probably right Gary. It was probably a combination of the SOP and instructors. All my instructor were in the 4000 license number or below.

A few replies back I said I never saw insulation on a condensate drain pipe. I can't say that I can remember seeing much of a problem with condensation either. Yesterday I saw one sweating quite a bit.

image0001.jpg

Interesting. Do you know if it was it clogged? I could see how normal flow may not condense, but that pic shows A LOT of condensation.

Originally Posted by Kris Svendsen

Interesting. Do you know if it was it clogged? I could see how normal flow may not condense, but that pic shows A LOT of condensation.

I would have normally investigated this more, but it was an 8-1/2 hour inspection (not including report) and I did not take the time. The drain pipe was connected to a plumbing vent stack and of the four air-handlers in four different attics all of them had about the worst access I have ever seen.

Would like to add a slight twist to the condensate drain discussion. Have recently experienced trouble with a condensing furnace condensate drain line freezing in an unprotected region of a structure, resulting in water damage to building. Have searched state mech code [NC] and am unable to find requirement for freeze protection of this type of condensate drain. Anyone know of freeze protection requirement?
//steve

Originally Posted by Steve Morelen

Would like to add a slight twist to the condensate drain discussion. Have recently experienced trouble with a condensing furnace condensate drain line freezing in an unprotected region of a structure, resulting in water damage to building. Have searched state mech code [NC] and am unable to find requirement for freeze protection of this type of condensate drain. Anyone know of freeze protection requirement?
//steve

Being "required" may well depend on when the house was constructed and the code which was applicable at that time.

That said, if you have searched the NC codes, then go to the 2012 NC Residential Code, Plumbing Code Abridged for the Residential Code first: http://ecodes.biz/ecodes_support/fre...Plumb_2012.pdf

305.6 Freezing and 305.6.1 Frost protection.

The reason for going to the Plumbing Code first is that condensate drain lines are still drain piping and drain piping is covered in the Plumbing Code. Condensate drain lines are also addressed in the Mechanical Code, albeit not to the extent that the Plumbing Code addressed drain lines.

The 2012 NC Residential Code, Mechanical Code Abridged for the Residential Code is here: http://ecodes.biz/ecodes_support/fre..._Mech_2012.pdf

Go to 307.1 Fuel-burning appliances.

Those are from the 2012 NC codes, which may not have been adopted at the time your house was constructed and therefore would not have been applicable.

Nonetheless, though, now that you have had a problem with it you now know that you need to provide protection for that piping to prevent or at least reduce the likelihood of future issues from it happening again.