phil327 wrote:Another conversation with one of the owners regarding the lobby.
Do you know if a building lobby requires ventilation, either an exhaust fan or windows that can be opened. This lobby has no heat or air conditioning. The lobby has a few wicker couches, all the mail boxes, and elevator and a door to a stair way. Does this make it living space?
It does not need to be "living space", just "occupied space".
OCCUPIABLE SPACE. An enclosed space intended for human activities, excluding those spaces intended primarily for other purposes, such as storage rooms and equipment rooms, that are only intended to be occupied occasionally and for short periods of time.
From the 2010 FBC-Mechanical
- 401.2 Ventilation required.
- - Every occupied space shall be ventilated by natural means in accordance with Section 402 or by mechanical means in accordance with Section 403.
- - In lieu of compliance with Section 403.1 through Section 403.3, mechanical ventilation may be implemented in compliance with ASHRAE 62.1.
- 401.3 When required.
- - Ventilation shall be provided during the periods that the room or space is occupied.
- SECTION 402 NATURAL VENTILATION
- - 402.1 Natural ventilation. [B]
- - - Natural ventilation of an occupied space shall be through windows, doors, louvers or other openings to the outdoors. The operating mechanism for such openings shall be provided with ready access so that the openings are readily controllable by the building occupants.
- - - 402.2 Ventilation area required. [B]
- - - - The minimum openable area to the outdoors shall be 4 percent of the floor area being ventilated.
- - - 402.3 Adjoining spaces. [B]
- - - - Where rooms and spaces without openings to the outdoors are ventilated through an adjoining room, the opening to the adjoining rooms shall be unobstructed and shall have an area not less than 8 percent of the floor area of the interior room or space, but not less than 25 square feet (2.3 m2). The minimum openable area to the outdoors shall be based on the total floor area being ventilated.
- - - - - Exception: Exterior openings required for ventilation shall be permitted to open into a thermally isolated sunroom addition or patio cover, provided that the openable area between the sunroom addition or patio cover and the interior room has an area of not less than 8 percent of the floor area of the interior room or space, but not less than 20 square feet (1.86 m2). The minimum openable area to the outdoors shall be based on the total floor area being ventilated.
- - - 402.4 Openings below grade. [B]
- - - - Where openings below grade provide required natural ventilation, the outside horizontal clear space measured perpendicular to the opening shall be one and one-half times the depth of the opening. The depth of the opening shall be measured from the average adjoining ground level to the bottom of the opening.
If the choice is for mechanical ventilation, then the minimum ventilation rate will likely be 50 cfm - the mechanical contractor doing the work would need to verify the amount of mechanical ventilation required.
If the choice is for natural ventilation, then the minimum ventilation opening size is 4 percent of the sq ft area, within the conditions provided for in 402 above.