A traditional cooling coil with the required number of rows allows the water at around the wet bulb temperature to pass inside the copper tubes. The tubes are lined with Aluminum fins to increase the heat exchange surface area. The Supply Air passes over this coil, thereby reducing the temperature and achieving the desired cooling. This water with heat absorbed from the Supply Airstream is then passed through a Secondary Adiabatic Heat Exchanger for heat removal and recirculated in the coil.

This is the type in which the water is passed in one section of plates, while the Supply Air passes through its adjacent section. Water cools the plate down to allow heat transfer from the Supply Airstream, thus reducing its temperature. Bleed Air flows counter-currently in the water section and is exhausted, which removes the heat from the water to allow recirculation.

This is a conventional cooling coil with copper tubes and aluminum fins for Air-Conditioning. It can be a DXNRF Coil allowing compounds of Freon gas to pass through its tubes or a Chilled Water Coil circulating low-temperature water. Temperatures in the range of 10-15*C can be achieved at the outlet for the Supply Air meant to be circulated in the Air-Conditioned areas. However, recirculation of room air is necessary to achieve the results.

• Fresh Air Intake section with louvers.
• Return Air Intake section either with louvers or dampers.
• Mixing Box with Fresh & Return Air Dampers.
• Cut-outs with Dampers which are suitable for manual as well as motorized operation.
• Only cut-outs

• Primary function of filter is to purify the air by arresting the suspended solid/gas particles present in the air. There can be multiple levels of filtration depending upon the requirement and application to filter out the particles in the range from 20µ to 0.3µ
• Pre-Filter is having 20µ to 10µ filtration level. Fine Filter has 5µ to 1µ filtration level. And HEPA Filter has 0.3µ filtration level with different particle arrest efficiency. Filters can be of Box type, Flange type, Bag type, or Combination of two based on the requirement.
• Special kind of filters such as activated carbon filters to remove odor from the air, chemical filters to remove dissolved chemical compounds and gases from air, Electronic air cleaners (EAC), Electro static precipitators (ESP) etc can also be used.

• Heat Exchanger coils are tube & fin type heat exchangers mostly used to suffice the requirement of cooling, heating and dehumidification depending upon the requirement.
• These are Chilled Water Coil, Hot Water Coil, Direct Expansion (DX) coils and Direct Expansion with variable refrigerant flow (DX+VRF) coils. Water coils are having water as a heat exchange medium and DX coils have suitable refrigerant fluid.
• In DX coil more than two circuits can be Intertwined to cover maximum face area.
• Generally, these Heat Exchanger Coils have copper tubes having either 1/2”, 3/8” and 5/8”  diameter and Aluminum Fins. Headers of the coil can be of Copper or MS.

• Fan is a heart of the unit. It facilitates the movement of air to the conditioned space through AHU. There are different type of fans available depending upon the blade, impeller, construction, Application.
• Most commonly used fans are Centrifugal DIDW Forward / Backward curved belt-driven fan, SISW Forward / Backward curved belt-driven fan, Plenum (PLUG) type direct-driven fan with standard motor, Plenum fan with EC motor (EC Fan), DIDW Forward / Backward direct-driven fan, Axial Fan etc.

• Energy saving in AHU is possible with heat recovery components such as heat recovery wheel, plate type heat exchanger, heat pipe, run around coils.
• Heat recovery wheel is placed in such a way that 50% of the wheel area will be in return air stream and remaining 50% will be in fresh air stream. Return air will remove the heat from wheel, as the wheel is continuously rotating at slow pace this portion of wheel now comes in fresh air stream and will remove the heat from fresh air. Thus, energy recovery from return air to fresh air happens, resulting in overall heat load requirement.
• Plate-type heat exchanger works on the same principle as the heat recovery wheel. Return air stream & Fresh air stream will never come in direct contact with one another.

• Humidification section is needed in the unit when there is a specific requirement to increase in humidity level or to obtain cooling in dry climate areas. To achieve this, we can use cellulose pads, pan type humidifier, spray type humidifier.
• Use of cellulose pads are most common way to increase the humidity with cooling. These are made of cellulose material on which water is sprayed which humidifies & cools the air passing over the wet pad and supplied to conditioned space.
• In Spray type humidifier water is sprayed through nozzles which comes in contact with the passing air and due to the evaporative cooling, air gets cooled & humidified and supplied to conditioned space.

• Microorganisms which are suspended in the air and cannot be captured by regular filtration , causes significant threat to human health and have their unwanted effect on conditioned space.
• These micro-organisms such as Bacteria, Viruses, Moulds, Funguses etc. accumulates on to AHU components (which are in contact with the water, such as Coil Heat Exchanger & Cooling Pad). This may lead to uncomfortable odor of the air supplied to the conditioned space.
• Ultraviolet (UV) systems prevent the growth of all these microbial organisms and sterilizes the supplied air.
• As the air passes through the UV-C purification device or the surface is exposed to germicidal UV light, the genetic material of microorganisms is deactivated, preventing them from reproducing and rendering them harmless.

• Mist Eliminators are generally used to trap the water particles being carry forwarded by the air stream passing over a water component such as Chilled Water coil or cellulose Pad.-It can either be V-pass (2-bend) or W-pass (4-bend) type with PVC blade or Sheet metal blade depending upon the application.

• Electric heaters are used in air handling units as either a primary or secondary source of heating to achieve the sensible heat transfer / control humidification.
• The heating elements are in direct contact with the airstream. Which increases the temperature of the air passing over it.
• There are two types of electric heaters used in AHUs. Strip type heaters & Tubular type heaters. MOC can be either GI or SS.