Manhattan Condo Co-ops and brownstones: Mechanical Systems

This article covers a few basic aspects of Electrical, Plumbing, Heating and AC Systems. Electrical A few Renovation points   New York City has the most stringent electrical codes in the United States, exceeding the National Electrical Code in many areas.    If the apartment to be renovated has not had the electrical service legally upgraded after 1968 or you plan to have major new electrical loads (cooking equipment, steam room generator, electric dryer), you will need to bring up more power from the basement through a new “electrical riser”.    The size of the apartment will determine the allowance for circuits.    The number of circuit breaker slots required determines the capacity required for the electrical riser.    The total projected electrical load in an apartment will be far less that the maximum capacity of the riser. sp;  Some electrical devices (kitchen counter outlets, air conditioners, refrigerators ) must be on dedicated circuits and can not be combined with other loads even if the loads are small.    Electricians usually install the wiring for special use items. In some instances other contractors may do the system hookup of special devices, but the electrician usually installs the actual wire.    A convenience outlet must be located on every 12 feet of wall minimum. Extension cords are not allowed.    The circuit breaker box must be accessible.    A convenience outlet must be located on every 12 feet of wall minimum. Extension cords are not allowed.    Clothes closet lights must be enclosed, there may never be an exposed light bulb. A clothes closet may not have a switch or other electrical device within. Door jam switches are permissible.A few general manhattan electrical points   The electrical supply into the apartment is rated in Amperes and comes from the electric meter room via the “electrical riser”. There is a neutral or common wire that is grounded at the service entrance into the building. The conduit around the wires is considered the ground.    Existing wiring since the building was erected, is often running in electrical pathways called conduits. If an existing conduit is not available, then a flexible type of metal conduit called “Bx” cable is used.    ?The size of the wire and the distance from the meter area will determine the amount of electrical power that the apartment can draw and is the rated electrical riser capacity.    Each wire size has a recommended maximum load. The type of insulation around the wire also affects the application for the wire.    ?Insulation on wire is color coded; black, red and blue is used for the phase or hot wires, white is used for the neutral or common wire, green is used for a ground wire.Plumbing A few Plumbing Renovation Points    Many buildings have additional and more stringent guidelines than the NYC Building Department (DOB).    Gas service may originate from a building riser that feeds several apartments or from an individual riser that is metered for only one apartment.    All exposed pipes should be inspected while the walls are open.    Plastic drain and water pipes are prohibited in New York City because of the toxicity.    Waterproofing in shower stalls requires sheet lead under the tile.    Renovations may or may not require some gas pipe relocation.Heating, Ventilation & Air Conditioning A Few Heating System Points    Most Heating is supplied by steam generated from oil-fired boilers in the basement or from Con Edison via pipes under the street.    Most buildings are heated to a level comfortable to the coldest tenant.    Steam radiators are generally on or off with little temperature control in between.Ventilation    Every occupiable room such as a bathroom must have a window or be mechanical ventilated on a continues basis.    Fresh air must be provided to rooms that are mechanically ventilated and do not have windows.Basic Air Conditioning An air conditioner is basically a refrigerator without the insulated box. There are two parts to an air conditioner.    A Compressor compresses gas, which then runs through coils condensing into a liquid, this then runs through an expansion valve forming a gas.    This gas changes to liquid then eventually evaporates to become cold, low-pressure gas. This cold gas runs through a set of coils that allow the gas to absorb heat. The heat is absorbed from the air and is cooled, cooling down the air in an apartment.Air conditioning is measured by Btu capacity. BTU is the amount of heat required to raise the temperature of one pound of water 1 degree Fahrenheit. 1 BTU equals 1,055 joules. In heating and cooling terms, 1 “ton” equals 12,000 BTU. Basic Air Conditioning A few NYC AC points To size an air conditioner for your specific needs, contact an HVAC contractor or your general contractor will bring on an HVAC contractor.   Common types of NYC Air Conditioning:    Window AC units    Through-the-wall AC units    Central ducted AC systems    Central ductless AC systems    Many buildings do not allow additional AC thru-wall penetrations on the public facades.    Room air handler units are operated by individual room thermostats for total comfort control, efficient since only the areas requiring cooling are cooled.    Enclosures around the condenser packages are often sound proofed.    In NYC Package thru-wall units will have to meet federal and state energy efficiency requirements. All split systems must be acceptable to the DOB.