hvac system info

1. PROJECT
MANAGEMENT

2. INTRODUCTION
Ventilation
▪ Ventilation involves bringing in fresh air to provide oxygen for people
and to help carry away of carbon dioxide and body odors.
▪ Itis always needed whatever the climate. With the advent of modern
HVAC systems, fresh air is delivered via the heating and cooling
system.
▪ Both ventilation and passive cooling consider window positions
together with requirements of human occupants.
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3. WHAT DOES AN INTERIOR DESIGN PROJECT MANAGER DO? 3
Passive cooling replaces heated indoor air with
cooler
outdoor air. Cooling breezes are only available at
specific times and in specific places.
Much greater amounts of airflow is required for
passive cooling than for control of air quality.
Before the invention of mechanical ventilation,
the high ceilings common in buildings created a
large volume of indoor air that diluted odors and
carbon dioxide produced by occupants.Fresh air
was provided by infiltration, which along with
operable windows created a steady exchange of
air with the outdoors.

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Ventilation Systems
The basic components of a building ventilation system begin with an air source of acceptable
temperature, moisture content, and cleanliness.
A force is required to move air through the building’s inhabited spaces, with a means to
control its volume, velocity, and direction of airflow.
Finally, the system requires a means of recycling or disposing of contaminated air.
Natural Ventilation
Natural ventilation moves a source of fresh air at an appropriate temperature and humidity
through a building without fans.
Wind or convection moves air from higher to lower pressure areas through windows, doors,
or openings provided for the purpose, or though non-powered ventilators.
Mechanical controls adjust the volume, speed, and direction of the airflow. Contaminated air
is either cleaned and reused or exhausted from the building.
Using natural ventilation helps keep a building cool in hot weather and supplies fresh air
without resorting to energy dependent machines. However, in cold climates energy loss
through buildings that leak warm air can offset the benefits of natural cooling.

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Wind Ventilation
Wind‐powered ventilation is most efficient if there are windows on at least two sides of a room,
sides of a room, preferably opposite each other.
Where only a single wall abuts the outdoors, a casement window can help create a pressure
create a pressure differential that induces airflow.
Factors influencing airflow through buildings include pressure distribution around the building; the
the building; the direction of air entering windows; the size, location, and details of windows; and
details of windows; and
interior partitioning details.
The design of open floor plans can maximize airflow by minimizing the use of full height partitions.

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Comfort Ventilation
Comfort ventilation is the technique of using air motion across skin to promote thermal comfort. It is
promote thermal comfort. It is used in lightweight construction without air conditioning in hot and
conditioning in hot and humid climates.
Comfort ventilation still requires some insulation to keep sun on roof and walls from overheating
walls from overheating interior surfaces. Comfort ventilation is rarely completely passive. Window
passive. Window fans or whole house fans are usually needed to supplement wind.
wind.
Insulation is required and thermal mass is helpful for mostly air‐conditioned buildings, even in
buildings, even in humid climates. The mass slows temperature changes, allowing the air
allowing the air conditioning to be
turned off during peak electrical demand times.
For comfort ventilation, operable window area should be around 20 percent of the floor area, with
the floor area, with windows split roughly evenly between windward and leeward walls.

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Chimneys and Flues
When not in use, a large quantity of air rises through a fireplace chimney and is replaced by
and is replaced by infiltrating outdoor air. Closing the fireplace damper reduces, but does not
reduces, but does not eliminate, this problem as dampers rarely fit tightly. Air loss actually increases
loss actually increases when the fireplace is in use, inducing more infiltration throughout the

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Attic and Roof Ventilation
Thermal buoyancy—the rising of warm air—is a major cause of air leakage from a building’s living
from a building’s living space to the attic and then out through the roof. Solar heated air also comes
Solar heated air also comes in through the roof and attic.
Attic Ventilation
Ventilating an attic reduces temperature swings. It makes the building more comfortable during hot
comfortable during hot weather and reduces the cost of mechanical air conditioning.

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Mechanical Ventilation
Displacement ventilation may be required for most high‐rise
structures with central air distribution, depending on their design
and engineering. (See Figure 13.13) Displacement ventilation
introduces fresh cool air at floor level, and exhausts polluted
warm air through the ceiling. Vents must be kept clear
of obstructions. Openings should close tightly to prevent unwanted
infiltration.
Preheating Ventilation Air
Heating or cooling of makeup air can be used to heat building air. A
south‐facing (Northern Hemisphere) solar wall with a collector can be used
as a winter preheating device.
One residential system combines a wall with an exhaust air heat pump. The
house is under negative pressure, with forced exhaust air. Heat is supplied
from exhaust air heat pumped for
space heating or heating hot water. Fresh air is drawn through the specially
constructed walls. As a result, a slow, steady stream of cold air warmed by
insulation enters the building.
Restaurant kitchens, gym locker rooms, bars, and auditoriums require
extra ventilation. Lower rates are permissible for residences, lightly occupied
offices, warehouses, and light manufacturing plants.
Residential Ventilation Systems

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Design considerations for residential exhaust systems include the type of
cooking appliance and fuel, the location of the range or cooktop within the
kitchen, and the size and location of any hood. The type of fan and makeup
or replacement air available are considered. The size, length, and number of
turns in ducts to connect the fan to the exterior are also important.
In tightly constructed houses, negative pressure can

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Fans
Mechanical ventilation options include unit ventilator fans on the outside wall
of each room to circulate room air and replace part of it with outdoor air.
Window or through‐wall air conditioning units can also be run as fans. A
central heating and cooling system with coils of hot or chilled water will
temper the air in room ventilation units. Fixed location fans can provide a
reliable, positive airflow to an interior space.
Any time that air is exhausted from a building, makeup air must be supplied.
This can be done in a limited manner by infiltration through the building’s
envelope. Opening windows and
doors can also provide a supply of fresh air. Where mechanical equipment
exhausts a large volume of air, makeup air is introduced through vents in the
building envelope, and directed to
the equipment through ducts.

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Attic, Window, and Whole ‐House Fans
An attic fan reduces attic temperature and condensation damage.
Window fans should be located on the downwind side of a house, facing outward. When in use, a
outward. When in use, a window in each room and interior doors should be opened. A whole‐house

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Interior Design Implications
The architect and interior designer are both concerned with the locations and dimensions of
and dimensions of ductwork and piping. The noise generated by mechanical equipment is an
equipment is an acoustic concern for them both.
Early in the project, the architect must consider the size and location of central HVAC
central HVAC mechanical rooms, which may be either separate spaces or combined together.
combined together. HVAC requirements can have a substantial impact on the space plan, ceiling

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Interior Design Implications
Thermostat locations are determined by the engineer and are dependant upon the surrounding

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Interior Design Implications
Commercial office design is going through major changes.
Four basic types of office space may be interchanged within a flexible overall plan.

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Interior Design Implications
least one supply vent and one return or exhaust vent.

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19. Interior Project Stages
The interior design process has many stages which
undertakes across residential, hospitality and
commercial projects.
The stages include:
▪ Feasibility
▪ Concept
▪ Development
▪ Technical
▪ Production
▪ Tender
▪ Mobilisation
▪ Construction
▪ Post Completion
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Project Consultants and Resources - Other Consultants
Other consultants the interior designer might work with are landscape architects, industrial
designers, and graphic designers.

21. Diagrams and infographics
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22. 1. TRANSITION HEADLINE
Let’s start with the first set of slides