[Code of Federal Regulations]
[Title 24, Volume 5]
[Revised as of April 1, 2001]
From the U.S. Government Printing Office via GPO Access
[CITE: 24CFR3280.103]

[Page 113-114]
 
                 TITLE 24--HOUSING AND URBAN DEVELOPMENT
 
 CHAPTER XX--OFFICE OF ASSISTANT SECRETARY FOR HOUSING--FEDERAL HOUSING 
        COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
 
PART 3280--MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS--Table of Contents
 
                   Subpart B--Planning Considerations
 
Sec. 3280.103  Light and ventilation.

    (a) Lighting. Each habitable room shall be provided with exterior 
windows and/or doors having a total glazed area of not less than 8 
percent of the gross floor area.
    (1) Kitchens, bathrooms, toilet compartments, laundry areas, and 
utility rooms may be provided with artificial light in place of windows.
    (2) Rooms and areas may be combined for the purpose of providing the 
required natural lighting provided that at least one half of the common 
wall area is open and unobstructed, and the open area is at least equal 
to 10 percent of the combined floor area or 25 square feet whichever is 
greater.
    (b) Whole house ventilation. Each manufactured home shall be capable 
of providing a minimum of 0.35 air changes per hour continuously or at 
an equivalent hourly average rate. The following criteria shall be 
adhered to.
    (1) Natural infiltration and exfiltration shall be considered as 
providing 0.25 air changes per hour.
    (2) The remaining ventilation capacity of 0.10 air change per hour 
or its hourly average equivalent shall be calculated using 0.035 cubic 
feet per minute per square foot of interior floor space. This 
ventilation capacity shall be in addition to any openable window area.
    (3) The remaining ventilation capacity may be provided by: a 
mechanical system, or a passive system, or a combination passive and 
mechanical system. The ventilation system or provisions shall not create 
a positive pressure in Uo value Zones 2 and 3 or a negative pressure 
condition in Uo value Zone 1. Mechanical systems shall be balanced. 
Combination passive and mechanical systems shall have adequately sized 
inlets or exhaust to release any unbalanced pressure. Passive systems 
shall have inlets and exhaust of sufficient size to alleviate unbalance 
pressure conditions under normal conditions. Temporary imbalances due to 
gusting or high winds are permitted.
    (4) The ventilation system or provision shall exchange air directly 
with the exterior of the home, except it shall not draw or expel air 
with the space underneath the home. The ventilation system or provision 
shall not draw or expel air into the floor, wall, or ceiling/roof 
systems even if those systems are vented.
    (5) The ventilation system or a portion thereof may be integral with 
the homes heating or cooling system. The system shall be capable of 
operating independently of the heating or cooling modes. A ventilation 
system that is integral with the heating or cooling system shall be 
listed as part of the heating and cooling system or listed as suitable 
for use therewith.
    (6) A mechanical ventilation system, or mechanical portion thereof, 
shall be provided with a manual control and may be provided with 
automatic timers or humidistats.
    (7) Substantiation of the ventilation capacity to provide 0.10 ACH 
shall be provided for a mechanical system, or a passive system, or a 
combination passive and mechanical system.
    (c) Additional ventilation. (1) At least half of the minimum 
required glazed area in paragraph (a) of this section shall be openable 
directly to the outside of the manufactured home for unobstructed 
ventilation. These same ventilation requirements apply to rooms combined 
in accordance with Sec. 3280.103(a)(2).
    (2) Kitchens shall be provided with a mechanical ventilation system 
that is capable of exhausting 100 cfm to the outside of the home. The 
exhaust fan shall be located as close as possible to the range or cook 
top, but in no case farther than 10 feet horizontally from the range or 
cook top.
    (3) Each bathroom and separate toilet compartment shall be provided 
with a mechanical ventilation system capable of exhausting 50 cfm to the 
outside

[[Page 114]]

of the home. A separate toilet compartment may be provided with 1.5 
square feet of openable glazed area in place of mechanical ventilation, 
except in Uo value Zone 3.

[58 FR 55003, Oct. 25, 1993]