Air Conditioning

Air conditioning refers to the cooling and dehumidification of indoor air for thermal comfort. In a broader sense, the term can refer to any form of cooling, heating, ventilation or disinfection that modifies the condition of air

Air Conditioner

An air conditioner is an appliance, system, or mechanism designed to stabilize the air temperature and humidity within an area at a given time, typically using a refrigeration cycle but sometimes using evaporation, commonly for comfort cooling in buildings and motor vehicles.

Air Conditioner Types

Window type -

Window air conditioners are one of the most commonly used and cheapest types of air conditioners. To install one of these units, you need the space to make a slot in the wall, and there should also be some open space behind the wall.

Split type -

Split air conditioners are used for small rooms and halls, usually in places where window air conditioners cannot be installed. However, these days many people prefer split air conditioner units even for places where window air conditioners can be fitted.

Package type –

Packaged air conditioner models are used for medium sized halls and multiple rooms on the same floor. They are usually used for applications where air conditioning of more than 5 tons is required. This article describes the types of packaged air conditioners.

Central Air Conditioning –

Central air conditioning plants are used for applications like big hotels, large buildings having multiple floors, hospitals, etc, where very high cooling loads are required. The article describes various possible arrangements of central air conditioning plants.

Central air conditioning plants are used for cooling whole buildings comprised of many floors, big hotels, large halls with a seating capacity of hundreds or even thousands of people, cinema halls, auditoriums, banks, offices, airports, large hospitals etc. Designing the central air conditioning plant for a particular application is a long and tedious process as the HVAC designers have to find out heat load in each and every room or space that is to be calculated. Such systems can be designed only by expert HVAC design companies who have extensive experience of installing these plants.

About selected building

This building has been leased by NDB bank to establish a branch at Maharagama. So they have been modified the building according to requirements by establish manager room, assistant manager room, admin head room, accounting head room, toilets and ATM rooms, using partitions. There is a glass panel in front of the building to get the aesthetic appearance. Total size of the building is 340m². Floor height is 3m and this is the first floor of the building. We selected this building to propose a most suitable ac system. A bank it is very essential to have a ac system as it has lot of branches, computers, staff, customers.

Selecting the most suitable Air Conditioning System

Identify the most appropriate Air Conditioning system is the most critical part in selection process because the selected system must be able to provide maximum cooling at the lowest possible cost. There are some important factors to be considered before selecting the suitable one.

¨ Location and Size of Building

¨ Orientation Shape

¨ Load of people

¨ Installed machineries

¨ Expect time for day

¨ Lightning Appliances

¨ Electrical, Gas and Water services

¨ Ave. weather condition

Cooling load is calculated by considering all the above factors.

Cooling loads of each room

Manager’s room = 18377 BTU

Assistant Managers room = 10144 BTU

Administration Head room = 10144 BTU

Chief Accountants room = 10144 BTU

ATM machine room = 12457 BTU

Office area = 190854 BTU

Total load = 252120 BTU

Any of the available types of Air Conditioning systems can be installed in to this building. In this case client’s requirement is to install an Air Conditioning system which provides maximum cooling at lowest possible cost to the first floor of this building which is going to rent to the NDB bank. The most appropriate Air Conditioning System to this building is the split type.

Estimate for the Proposed System

Capacity	Brand
	LG		Haier		Deluxe
12000 BTU	HSC1264SA2	Rs 84900	HSU-12LE03	RS.73,900	Rs. 69900
18000 BTU	HBS189BC	Rs. 130000
24000 BTU	LS/K2462QC	Rs. 224990	HSU-24LE03	RS.118,500	Rs. 184990
36000BTU	HTC368DLAO	Rs.297300

Why split Type is most suitable

This Air Conditioning system is designed by giving priority to the following factors.

¨ Low initial cost

¨ Simple installation

¨ Aesthetically pleasant

¨ Provide minimum noise

¨ Easy to alter and maintain

¨ Delivery air over long distance

¨ Can separately control the temperature in each room

Split type air conditioning system is selected because of these advantages.

¨ Initial cost is low

¨ Installation is simple

¨ Noise is lower

¨ Cost effective

Split type vs. Wall type

The cheapest alternative air Conditioning system to this building is wall type air condition. But it provides the maximum noise among the available types because the compressor is placed inside the conditioned area. Therefore it becomes very uncomfortable to users.

Another disadvantage of using wall type instead of split type is wall type has limited range of capacities. In this building heat gain of some areas are greater than 100,000 Btu’s. Since wall type has small range of capacities it is not suitable for the client’s requirements.

When considering about the aesthetic appearance wall type one is not pleasant. Therefore it cannot be install to place like bank.

Therefore according to the function of the building and clients requirements split type is better than wall type.

Split Type vs. Packaged type

Package type and split type both has both has produce minimum of noise because of its compressor is placed in the out door unit. But package type conditioning system has very high capacities than split type. But the heat gain of this building is not too much higher. Heat gain in some of the cubicles is less than 12000 BTU. Therefore it is unnecessary to use a packed system to a building like this.

Both these types have an indoor unit and out door unit. The indoor unit of the package type is very big than the split type. Therefore it takes large amount of space of the building. This is also affect to the aesthetic appearance of the building.

Because of the above mentioned reasons split type is more suitable than the packaged type.

Split type vs. Central Air Conditioning System

Normally central air conditioning is used in very large buildings such as big hotels and commercial buildings where the total heat gain is very high. The heat gain of the selected building is not too high. Therefore it is unnecessary to use a central air conditioning system in his building.

From the available types most costly air conditioning system is the central air conditioning system. When using a central air conditioning system it is need to allocate the space for plant room. Therefore the usable area of the building is reduced. As this is not a very big building it is a waste to design a central type air conditioning system to this kind of building.

Well design duct system is need for a central air conditioning system to distribute and collect the air in conditioned area. This could be done only with the help of specialized person. The installing cost is increased due to these reasons. It is not cost effective.

Maintenance and repair of central air conditioning system is very complex and this can be done only by with the help of expertise persons. Therefore have to commence a maintenance section to repair and maintenance. It takes additional cost. Therefore central air conditioning is not suitable to a building like this.

Central air conditioning is not allowing user to separately control the temperature in the individual rooms. As this is a bank it is big disadvantage of using a central air conditioning system.