Heat, Ventilation and Air Conditioning (HVAC) systems are a vital part of any building structure as they provide occupants and users with comfortable and healthy environments. Using three properties – thermodynamics, fluid mechanics and heat transfer – HVAC systems regulate things like temperature, humidity and the presence of fresh outdoor air inside. HVAC systems are particularly important for maintaining environments in structures like skyscrapers and aquariums.
HVAC systems and their individual components were products of the industrial revolution which called for new inventions of systems that could provide factory workers with acceptable indoor air quality and thermal comfort. The demand for innovative new systems led to all sorts of ideas for modernisation, higher efficiency and system control but it was the inter-relational HVAC functions that commanded the most attention and made the biggest impact. They made workers’ long shifts bearable and costs were relatively low for installation, operation and maintenance.
Since the industrial revolution HVAC systems have been developed, modified and revolutionised but the basic principles of the three main functions remains to be at the engineering heart of most homes and businesses. You may be looking for a new heating system, a simple extractor fan or the full works – whatever it is you’re after, it is always a good idea (and an interesting read!) to learn a little bit more about the HVAC system. Let’s start with heating:
- The ancient Romans are usually credited for introducing central heating to daily life. They installed air duct systems (hypocausts) in the floors and walls of their public baths and private villas
- A heater is an object that either emits heat or enables a separate object to increase its own temperature. The most common type of heater is domestic, used to generate heat and keep occupants warm. Other heaters include ovens and furnaces
- The type of heater you have depends on whether it uses solids, liquids or radiation to transfer heat. Heaters can use conduction (heat transfer through solids), convection (heat transfer through liquids) and radiation (heat transfer through gases)
- Central heating warms entire houses and public buildings. The systems usually contain a boiler, furnace or heat pump to warm water, steam or air in a central location (e.g. a furnace or boiler room)
- Water-based heat transfer (hydronics) uses ducts and forced air systems or piping to distribute heated fluid to radiators which will in turn transfer the liquid hear to air. These radiators can be either wall mounted or underfloor
- Hot water boiler heating systems use a pump to circulate heat around a distribution system of heat exchangers (radiators, baseboards, hot water coils etc.) to heat both rooms and water
- Duct work systems conduct both warm air (heating) and cooled air (air conditioning) depending on the setting. These systems also filter air, removing dust and pollen particles
- Electric heat sources work when ribbons of high resistance wire are heated. They are normally potable and often used as back up or additional heating
- Heat pumps first grew in popularity in the 1950s. They extract heat from the ground (geothermal) or from the exterior air which can then be used to heat water, interior air or both
- Heating systems can pose the risk of bad connections, dangerous by-products and carbon monoxide so installation and maintenance work should be carried out by experienced or certified professionals
So there are a few facts about the heating component of the HVAC system. If you want to learn more about the ventilation and air conditioning components, check back here for more blog posts!