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Updated: Feb 6, 2023


In the previous post on HVAC Systems, we talked about what HVAC is and the importance of HVAC.


Climate-control systems all have three main elements:

  1. A source of warm air, such as a furnace, and a source of cool air, such as an air conditioner.

  2. A means of air distribution, usually through ducts or pipes

  3. A control unit, AKA a thermostat, to regulate the system

In a centralized HVAC system, both warm and cool air can be routed through the same ducts and regulated by one thermostat. Heating and cooling act on the principle that heat transfers from a warmer object to a cooler one.

Contrary to its name, a heat pump is a climate control unit that both heats and cools the air. In cooler weather when you turn up the thermostat, the furnace consumes the oil, gas, or electricity that powers it and produces heat that is then distributed around your home through ducts or radiators, registers, or heating panels.

In the hotter months, a refrigerant gas inside a coil in your air conditioner is cooled to a liquid state when you turn on the AC. Warm air chills when it comes into contact with the cooling coil and is then sent through your space via ducts or directly from your AC unit.

 HVAC companies in Nigeria


There are three main distribution systems to move hot and cold air around your room, offices, or commercial space. A Forced Air System moves temperature-controlled air through metal ducts via a blower. Gravity Systems are installed in basements and work on the principle that hot air rises and cold air sinks. As the air is heated, it rises and cool air sinks down, eventually reaching the unit and being reheated. Radiant Systems can be installed under floors but they usually heat implements like radiators, which then distribute the heat around the room.


All HVAC systems have four main elements that work together. Different brands and models may have their own special features or be of better or worse quality, but the basic elements are similar:

  1. The furnace is fueled by natural gas or oil to heat air to the right temperature through a heat exchanger. Furnaces are usually found in basements, attics, or in some cases, specially built closets.

  2. The air conditioning unit uses electricity and has a refrigerant that cools the air. When hot air comes through the AC unit, it is sent outside while cool air is blown in. Unlike furnaces, AC units are usually installed on the outside of the home.

  3. The thermostat is the “brain” of the system and the element you will interact with most. It controls temperature and any other features that your system may have and turns different elements of the system on or off.

  4. Ductwork is the transport system for hot and cool air through the home. In modern homes, ductwork is factored in beforehand and usually installed above ceiling and behind walls.


Your HVAC is controlled by the thermostat. Thermostats are heat sensitive and control temperatures by detecting current air temperatures and reacting to bring the temperature back to the preferred temperature you have set, or the setpoint. If the temperature in the room is higher than the setpoint, the thermostat will automatically turn on the air conditioner and when it’s too cold, it will turn on the furnace.

Common HVAC System Types:

  • Window / Split AC: This is the most commonly used HVAC system in Nigeria, usually used homes, offices, smaller room and spaces.

split ac

  • Duct-able Splits : Duct-able Air Conditioner is a split air conditioner in which conditioned air from the indoor unit is passed into the room using circular/ oval/ rectangular ducting

duct able splits

  • Packaged Units : A packaged unit is a type of air conditioning system in which all parts are contained in one convenient location.

daikin packaged units
Packaged Units

  • Fan Coil Units : A fan coil unit (FCU) is a device that uses a coil and a fan to heat or cool a room without connecting to ductwork. Indoor air moves over the coil, which heats or cools the air before pushing it back out into the room. FCUs can be less expensive to install than ducted systems, and are available in ceiling, floor-mounted and freestanding configurations.

Fan coil units in Nigeria
Fan Coil Units

  • VRV Units: The name VRV * derives from this technology that we call “variable refrigerant volume.” VRV is a trademark of Daikin Industries, Ltd. This technology circulates only the minimum amount of refrigerant needed at any one time and enables individual climate control of air conditioning zones.

VRV Units in NIgeria
VRV Units

  • Direct Expansion System: Direct expansion Air Conditioning System is a common air conditioning system that uses condensed refrigerant liquid (Freon) directly to cool indoor air.

Direct Expansion system in Nigeria
Direct Expansion System

  • Chilled Water System : Many climates have hot weather. Some places are hot year-round.

But that doesn’t mean that the inside of buildings needs to be hot.

While the temperature outside can sometimes be over 100 °F, the temperature inside the building can be a comfortable 74 °F. This is all thanks to the chilled water system.

Chilled water systems provide cooling to a building by using chilled water to absorb heat from the building’s spaces. At the heart of the water chilled system, a chiller removes heat from water by means of a refrigeration cycle.

Chilled Water System HVAC
Chilled Water System

Here in Nigeria the most commonly used HVAC Systems are split system, duct-able split, fan coil, VRV units and packaged units. At Coldtech most of our HVAC systems are built with high quality materials and brands that have systems that boast high-performance compressors, which operate in tandem with their high-efficiency coil design. We use quality brands like Daikin, Panasonic, Carrier, Whirlpool and Bluestar. Feel free to contact us on any enquiry as regards to building, construction, installation and distribution of HVAC, Coldroom, Chillers and Blast freezers.

We also do procurement, We have a team that handles our procurements effectively. We have done a number of procurement as regards to HVAC and Coldroom in Lagos, Abuja and couple of other places in Nigeria.


HVAC Refrigeration Cycle
Refrigeration Cycle

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