Warm Air Heating

Introduction

Warm air heating is used in a variety of buildings where heating systems that use boilers or radiators are not suitable. While warm air heating systems can be used in a huge range of applications, they are particularly popular in large, non-domestic buildings such as factories and warehouses.

It is thought that we can trace warm air heating as far back as the 3rd century when the Roman Emperor Heliogabalus ruled and his palace was said to be heated with warm air. This was achieved through the use of a stove which was located in a brick chamber under the rooms of the palace. Air from outside was then channelled through ducts and then filtered through the palace, warming the rooms as it travelled.

Types of warm air heating

There are a number of different warm air heating systems which use a variety of techniques for warming the air. However, all of these systems push the warm air around a duct network using fans.

• Gas-Fired – this is the most popular type of warm air heating system and involves the use of a gas flame which cold air is drawn across.
• Air-to-Air Heat Pumps – these work in much the same way as air conditioning units, but can be inefficient.
• Heated Ventilation – this is usually a small heat source, so it is unsuitable for large buildings. It can involve an air-to-air heat pump, a wet heat exchanger or an electric-resistance heater.
• In-Ground Pre-Heating – this system uses warm air from underground, which is typically 8-12°C at depths below 1.5m. The air is drawn up through pipes and the pre-heated air is used in an air-source heat pump connected to the ventilation system.

Benefits of warm air heating

Warm air heating is a popular choice for a number of reasons, including:

• Reduced Fuel Usage – gas-fired warm air heating systems are particularly fuel-efficient, making them relatively inexpensive to run.
• Quick Warm-Up Times – a system that allows for quick warm-up times is particularly appealing for businesses where a large space needs to be heated to a comfortable level before staff arrive for work.
• Help to Prevent Damp – by moving hot air around a space, the likelihood of damp can be reduced, improving working conditions.
• Space Efficient – as there is no need for radiators to heat the space, warm air heating systems can be a good choice for factories or warehouses where space is precious.
• Quiet Operation – the ability to operate quietly is often important in buildings used for work. Warm air heating systems are typically much quieter than some other heating options.

Related articles on Designing Buildings Wiki:

• Everything You Need to Know About Evaporative Cooling.
• Workplace Air Conditioning.
• Radiant Heating and Fuel.
• Building Heating Systems.
• Heating Ventilation and Air Conditioning HVAC.
• Air Conditioning.