ENGINEERING

Engineering Assignment



Engineering Assignment

Introduction

This paper aims in building heating, ventilation and cooling design of a primary school building. The three aspects which will be discussed and designed relates to colling, heating and ventialation of the school building. These designs nto only provide the proper ventialtion and cooling, it is also design in sucha way that it provides complete safety for the children in primary schools.

Figure 1: School Map design

Suitable Heating System For the School Building

Dual Duct Systems: Appropriate

The dual-duct system employs two air ducts; one cold air duct and one warm air duct from the air-handler to the conditioned spaces. Figure below shows the schematic of a dual duct, constant volume system. As shown in the figure, the supply air fan splits the flow into two streams. One stream flow through the cooling coil and gets cooled and dehumidified to about 52°F, while the other stream flows thru the heating coil and is heated to about 95-110°F.

The cold and hot streams flow through separate and parallel ducts. The ducts are not necessarily of equal size, depending upon building heating and cooling loads. Before each conditioned space or zone, the cold and hot air streams are mixed in required proportions using a mixing box arrangement, which is controlled by the zone thermostat.

The total volume of air supplied to each zone remains constant; however, the supply air temperature varies depending upon load. The system is well suited for providing temperature control of individual spaces or zones. Return air is accomplished through a single duct system.

Figure: 2

Reason For Selecting this System:

Cooling in some zones and heating in other zones can be achieved simultaneously;

Good temperature and humidity control - system is very responsive to variations in the zone load, thus it is possible to maintain required conditions precisely;

Zoning of central equipment is not required;

Adaptable to either constant volume or VAV systems;

Since total airflow rate to each zone is constant, it is possible to maintain proper IAQ and room air distribution.

No seasonal changeover is necessary.

Types of other Heating System

The following heating system categories apply:

Steam or Hot Water Boilers produce hot water or steam which is delivered through pipes to space heating equipment. Key components to a boiler are the combustion chamber, burner, and the heat exchanger.

Central System with Heating Coils is air conditioning systems that are centrally located in the building, or on the building roof. These units may provide heating using a hot water or steam heating coils.

Reheat Coils in Air Distribution System are heating coils that are located in the ductwork near the distribution point to control the temperature in an individual zone.

Packaged Units are factory assembled air conditioning units equipped with the ability to heat or cool. Heating is generally provided using gas fired heat exchanger or electric resistance heating coils.

Forced Air Furnace heats by delivering warmed air to the spaces in a building. Components of the furnace are a heat exchanger, fuel burner, and air blower.

Heat Pumps are factory assembled units with the capacity to heat and ...