YEAR ROUND AIR CONDITIONINGShubham GadeSamay ShahParijat MalikDivesh JumaniAditya Bharadwaj

contents

• History • summer Air Conditioning system• Winter air conditioning systems• Year rounnd air conditioning systems• Design Features for year round air

conditioning• Applications

Factors affecting comfort air conditioning

1) Temperature of air: Maintenance of any desired temperature within closed space irrespective of the outside temperature. This is done by addition or removal of heat

2) Humidity: Maintaining the RH means to maintain the moisture of the the air by removing or adding the moisture by proper means.

Human body is comfortable at 210C and 60%RH

• 3) Purity of the air: We do not feel comfortable while breathing contaminated air even if it is at comfortable temperature and RH. So proper filtration and cleaning of the air is required

• Motion of air Circulation of the air is important to maintain the constant temperature. So there must be equi-distribution of the air throughout the space to be conditioned.

Components of air conditioner• Circulation fan- Move the air to and from the room• air conditioning unit- It is unit which consists of cooling and

dehumidifying processes for summer and heating and humidification for winter.

• Supply duct- It directs the conditioned air from the circulating fan to the space to be air conditioned at proper point.

• supply outlet- These are grills which distribute the conditioned air evenly in the room.

• return outlets- these are the opening in a room surface which allow the room air to enter the return duct

• Filters – The main function of the filter Is to remove dust , dirt and other harmful bacteria.

Summer air conditioning

• It is used where cooling and dehumidification of air is required • Hot flows through the damper, and mixes up with recirculated

air.• Mixed air passes through the filter • Air passes through the cooling coil whose surface temperature

is below the DPT of the air• Air gets cooled and dehumidified, condensed water gets

collected I the sump• After that it passes through the heating coil to get heated to a

designed temperature.• Conditioned air is supplied to the room by fans.

Flow diagram of summer air conditioning unit

• In few areas in the world it is vary difficult to live in winter

• Winter air conditions are used to heat the space for human comfort

• Its input and output is reversed to that of the summer air conditioner

• outside cold air is taken in and hot, humidified air is supplied to the room.

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Winter air conditioning

• In winter outside air temperature is less than the human comfort temperature and RH is also less.

• Its components are same as that of the summer air conditioning system

• Only the difference is heating coils are used whose temperature is greater that DBT of incoming air

• Air gets heated and humidified to a designed condition and supplied to room

Flow diagram of winter air conditioning system

Year round air conditioning system

• In several countries both winter and summer is uncomfortable

• Under such adverse weather condition air conditioner must provide comfort conditioning throughout the year

• Such system is known as year round air conditioning

•

Functions of Year round air conditioning

• Heating and humidification of air in winter• cooling and dehumidification in summer

Working of Year round air conditioning unit

Year round air conditioning can be obtained by

Using vapour as a refrigerant with additional humidifier and re-heater

Air washer

• In air washer an air is passed through the water stream

• Temperature of water is below DPT of incoming air for cooling purpose

• Temperature of water is above DBT of the incoming air for heating purpose.

• According to the outside air condition and room designed condition temperature of water is maintained either by external cooling or heating.

Air Washer

By using vapour as a refrigerant

• In this system cooling and heating coils acts as evaporator and condenser

• Vapour is used as a refrigerant • Compressor is required for circulation of

refrigerant • Valves are used to control the flow rate and

direction of the refrigerant according to the requirement

• Pumps are used to regulate the flow of water

Year round air conditioning for winter

Year round air conditioning for winter

1) Cold air is taken in, mixed with the recirculated air

2)It is passed over the heating coils which acts as a condenser and gets heated

3) It is then humidified, by passing it through humidifier

4) This conditioned air is supplied to room where hot and humid air is required

• Refrigerant is then passed through the to the evaporator where it evaporates using outside air.

• Receiver and compressors are required for the proper circulation of the refrigerant.

Year round air conditioner for summer

• Hot outside air is taken in, it is passed through filters

• Air is mixed with the recirculated air • It is now passed through the cooling coils

which acts as an evaporator• Cooled and dehumidified air is supplied to

room

• Refrigerant is passed through to the condenser where it condenses and returns to the receiver

• Condensation is done by the outside air only.

Year round air conditioning- setting for summer

• An evaporator during the winter operation acts as a condenser in summer and vice versa .

• In both the systems condensation and evaporation of refrigerant is done using the outside air so no external cooling or heating is required

• Proper valve adjustment is required and its control is required for proper functioning of system