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Historic Preservation - Technical Procedures

Spectitle:

Guidelines For Locating New Ducts, Grilles, Light Fixtures And Switches In Historic Buildings

Procedure code:

1501003S

Source:

Prsrvtn Ntbk Series/Mech & Elec Systems For Historic Bldgs

Division:

Mechanical

Section:

Basic Mechanical Requirements

Last Modified:

02/24/2012

Details:

Guidelines For Locating New Ducts, Grilles, Light Fixtures And Switches In Historic Buildings



GUIDELINES FOR LOCATING NEW DUCTS, GRILLES, LIGHT FIXTURES AND
SWITCHES IN HISTORIC BUILDINGS


This standard includes general guidelines for locating new
mechanical and/or electrical systems in historic buildings with
minimal adverse impact on the building's appearance or character.


GENERAL:

    When possible, install new systems that are reversible.

-    Reuse existing holes where possible.

    Use existing interstitial spaces to conceal systems.

-    Conceal wiring when possible.


DUCTWORK:

    Conceal piping and ductwork as much as possible, but DO NOT
    install suspended ceiling systems to do so.

-    If suspended ceiling systems must be installed, DO NOT allow
    system to abut glazing.  The historic appearance of the window
    should be maintained where possible.  This can be accomplished
    by "boxing" around window heads and leaving the complete
    window exposed to view.

    Where piping cannot be easily concealed by providing
    alternative routes through less significant spaces, provide
    gypsum board enclosures of the minimum size necessary to
    sufficiently conceal the pipes.

-    Preserve ornamental walls and ceilings as much as possible.
    Avoid penetrating or attaching to ornamental finishes.  

    1.   Where possible, place pipes, conduit, etc. along recessed
         ledges or other areas of minimal visibility.

    2.   Where possible use piping of minimum diameter for
         purposes specified.

    3.   Paint pipes, conduit, etc. where possible to blend with
         adjacent finishes.

    4.   Where possible, use decoration patterns to disguise new
         placement of wiring or systems.

    Conceal ductwork in unused closets when possible and provide
    adequate ventilation.

-    Use an air-sampling system instead of a smoke detector when
    possible; only a small hole in the ceiling is required and
    very little space in the ceiling is required for the pipe.

    Conceal sprinkler heads and smoke detectors in decorative
    plaster ceilings.

-    Use unused fireplaces for return air ducts.

    Use permanently placed furniture to disguise ductwork.


GRILLES:

-    Reuse original hardware, such as grilles, etc. where possible.

    Specify new grilles, light fixtures, etc. to match original as
    closely as possible, in material and pattern.

-    If reuse of an existing grille is not possible, leave original
    grille in place and locate new grille within five feet of
    original location - preferably on a non-ornamental surface
    such as flat plaster.

    CAUTION:  FOR SOME SYSTEMS SUCH AS FIRE ALARM PULLS AND
    BELLS/HORNS, FIRE SAFETY STANDARDS MAY PROHIBIT THE RETENTION
    OF A DEFUNCT SYSTEM, AS THIS MAY CAUSE CONFUSION BETWEEN THE
    ACTIVE AND INACTIVE SYSTEM DURING AND EMERGENCY.  


LIGHT FIXTURES:

    Rewire, clean and refinish original fixtures when possible.

-    NEVER attach fluorescent fixtures directly to ceiling
    medallions.

    Conceal the light source when installing indirect lighting.

-    Introduce as few new fixtures and holes in the ceiling as
    possible.

    Provide emergency lighting that is as unobtrusive as possible;
    use a small fixture if possible; make sure the battery pack is
    concealed.

-    Conceal ambient lighting behind ceiling moldings when
    possible.


SWITCHES:

    Conceal conduit for light switches, fire alarms and other
    controls behind decorative surfaces if possible rather than
    attaching it onto the surfaces.

-    Paint switch plates and access panels separately so they can
    be easily removed.

    Conceal fire alarm equipment behind unused heating grilles.

-    Use wireless fire alarm systems when possible to eliminate
    unsightly conduit and wiring.

    Conceal electrical panelboards in unused closets when possible
    and provide adequate ventilation.

-    Conceal smoke detectors in decorative plaster ceilings.

                         END OF SECTION