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    Jeff Eastman's Avatar
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    Default Secondary Condensate Drain line

    Last edited by Jeff Eastman; 12-19-2007 at 02:55 PM.
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    Default Re: Secondary Condensate Drain line

    Quote Originally Posted by Jeff Eastman View Post
    Is a secondary condensate drain line (NOT TO CONFUSE WITH SECONDARY CATCH PAN DRAIN LINE) required for a system installed on top of a furnace in a closet (living space closet).
    *IF* a secondary condensate drain opening is provided (and it usually is) it should be used.

    There are some units which do not provide for a secondary condensate drain opening and thus no secondary condensate drain line can be installed.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

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    Default Re: Secondary Condensate Drain line

    Jerry, I am surprised at you, how does your answer square with the requirements you posted?

    From the 2006 IRC.
    - M1411.3.1 Auxiliary and secondary drain systems. In addition to the requirements of Section M1411.3, a secondary drain or auxiliary drain pan shall be required for each cooling or evaporator coil where damage to any building components will occur as a result of overflow from the equipment drain pan or stoppage in the condensate drain piping.
    Older systems may not have a secondary drain, but all newer ones installed inside a building should have a secondary drain or alternative as provided in the exceptions. Most retrofits will not have a drain line in place, but a float switch, etc. should be used.
    Jim

    Jim Luttrall
    www.MrInspector.net
    Plano, Texas

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    Default Re: Secondary Condensate Drain line

    Quote Originally Posted by Jim Luttrall View Post
    Jerry, I am surprised at you, how does your answer square with the requirements you posted?
    MII (manufacturer's installation instructions)

    Older systems may not have a secondary drain, but all newer ones installed inside a building should have ...
    I agree with the "should have", however, I've seen some (mainly water-to-air units in condos) which are not that old and have no secondary condensate drain connection.

    To me, I don't like the alternatives which allow not installing an auxiliary drain pan, but even those are now in the code.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

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    Default Re: Secondary Condensate Drain line

    Jerry, help me get this right, you are saying; If there is no secondary condensate drain provided, then one of the other alternatives MUST be used, correct? The MII would pertain to the installation of the unit and its drain(s), but not the need for a external drain pan to meet the code, right?

    Jim Luttrall
    www.MrInspector.net
    Plano, Texas

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    Default Re: Secondary Condensate Drain line

    Quote Originally Posted by Jim Luttrall View Post
    Jerry, help me get this right, you are saying;
    I guess I'm not sure what I've been saying, so I'll start over here. I think this evolved from starting with an answer to one question and then continuing over to an answer for another question, which could be considered to contradict the first question and answer.

    From scratch ...

    From the 2006 IRC. (underlining and bold are mine)
    - SECTION M1401
    - - GENERAL

    - - - M1401.1 Installation.
    Heating and cooling equipment and appliances shall be installed in accordance with the manufacturer’s installation instructions and the requirements of this code. (Jerry's note: "And", not "or".)

    - M1411.3 Condensate disposal.


    Condensate from all cooling coils or evaporators shall be conveyed from the drain pan outlet to an approved place of disposal. Condensate shall not discharge into a street, alley or other areas where it would cause a nuisance.
    - - M1411.3.1 Auxiliary and secondary drain systems.


    In addition to the requirements of Section M1411.3, a secondary drain or auxiliary drain pan shall be required for each cooling or evaporator coil where damage to any building components will occur as a result of overflow from the equipment drain pan or stoppage in the condensate drain piping. Such piping shall maintain a minimum horizontal slope in the direction of discharge of not less than 1/8 unit vertical in 12 units horizontal (1-percent slope). Drain piping shall be a minimum of 3/4-inch (19 mm) nominal pipe size. One of the following methods shall be used:
    - - - (Jerry's note: Then it goes on to describe the options available.)
    - - - 1. An auxiliary drain pan with a separate drain shall be installed under the coils on which condensation will occur. The auxiliary pan drain shall discharge to a conspicuous point of disposal to alert occupants in the event of a stoppage of the primary drain. The pan shall have a minimum depth of 1.5 inches (38 mm), shall not be less than 3 inches (76 mm) larger than the unit or the coil dimensions in width and length and shall be constructed of corrosion-resistant material. Metallic pans shall have a minimum thickness of not less than 0.0276-inch (0.7 mm) galvanized sheet metal. Nonmetallic pans shall have a minimum thickness of not less than 0.0625 inch (1.6 mm).
    - - - 2. A separate overflow drain line shall be connected to the drain pan provided with the equipment. This overflow drain shall discharge to a conspicuous point of disposal to alert occupants in the event of a stoppage of the primary drain. The overflow drain line shall connect to the drain pan at a higher level than the primary drain connection.
    - - - 3. An auxiliary drain pan without a separate drain line shall be installed under the coils on which condensate will occur. This pan shall be equipped with a water level detection device conforming to UL 508 that will shut off the equipment served prior to overflow of the pan. The auxiliary drain pan shall be constructed in accordance with Item 1 of this section.
    - - - 4. A water level detection device conforming to UL 508 shall be provided that will shut off the equipment served in the event that the primary drain is blocked. The device shall be installed in the primary drain line, the overflow drain line or the equipment-supplied drain pan, located at a point higher than the primary drain line connection and below the overflow rim of such pan.

    Options 1. and 3. refer to installing an auxiliary drain pan and how to do it with, and without, a drain line.

    Options 2. and 4. refer to how to do it *without* installing an auxiliary drain pan.

    Option 2. could be interpreted to allow a fitting to be installed into the one-and-only primary drain outlet and split into two separate drain lines "A separate overflow drain line shall be connected to the drain pan provided with the equipment.", thus providing a second drain line which would fulfill "This overflow drain shall discharge to a conspicuous point of disposal to alert occupants in the event of a stoppage of the primary drain."

    Option 4. states (no interpretation needed) that "A water level detection device conforming to UL 508 shall be provided that will shut off the equipment served in the event that the primary drain is blocked." and further states that "The device shall be installed in the primary drain line, the overflow drain line or the equipment-supplied drain pan,", i.e., no secondary condensate drain line is required, nor is an auxiliary drain pan under the unit. This "the overflow drain line" indicates and implies that there *may be* a 'secondary drain line' as the purpose of the secondary drain line is to serve as an 'overflow drain line' from the primary condensate pan supplied with the equipment.

    Don't have a secondary/overflow drain line opening? Install a water level detection device in the primary condensate line or in the primary condensate pan.

    Did I make that any clearer, or did I still muddy it up?



    Last edited by Jerry Peck; 12-11-2007 at 07:20 PM. Reason: speelin'
    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  7. #7
    James Duffin's Avatar
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    Default Re: Secondary Condensate Drain line

    I always suggest that the secondary drain from the coil be piped to "somewhere" to help prevent water running into the furnace if the main drain gets blocked. This is when the coil is mounted on the top of the furnace.


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    Default Re: Secondary Condensate Drain line

    Jerry, that's what I thought you meant, but I was not sure you said what you meant or that you meant what you said, but I knew you could tell me what you meant when you said what you meant

    Jim Luttrall
    www.MrInspector.net
    Plano, Texas

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