Latest generation of small duct HVAC systems

Ian Smith, Sales Manager, IBD Distribution, discusses the energy saving benefits of the latest generation of small duct high velocity HVAC systems.

Traditional heating, lighting and cooling methods need to be changed for more sustainable options in order to save energy within Europe.

40 per cent of Europe's energy is currently spent on heating, lighting and cooling homes and offices.

Forecasts show that by 2030, Europe will import 70 per cent of its energy, with the UK's supply of gas ceasing within a relatively short period.

The EU estimates that 22 per cent of the energy that is currently being used in buildings could be saved by next year by changing the way that our buildings are heated and cooled.

This approach will also help to reach CO2 reduction targets and meet the challenge of climate change.

The use of natural ventilation, when combined with an air conditioning system, reduces energy consumption.

The latest generation of small duct high velocity air conditioning (sdHVAC) systems provide an effective solution.

Capable of delivering constant, comfortable heating and cooling in today's living and working environments, they maximise the potential of renewable energy.

Small duct systems are a relatively new concept in the UK although they have existed for around 50 years in the US and Canada.

Their arrival in the UK created opportunities to demonstrate its advantages over traditional air conditioning and heating systems.

Whilst they did this, their shortcomings were evident too in terms of design and performance that were not really suitable for the more discerning European market.

Imperial sizes, noise levels during operation, non-compliance with European standards and lack of aesthetic appeal to the specification market were just some of the issues encountered.

The latest generation of European designed and manufactured sdHVAC systems have taken these shortcomings into account and the result is a new generation of products with a strong emphasis on higher energy efficient performance, the incorporation of industry leading technologies as well as style and aesthetic qualities.

The small duct high velocity systems use mini ducts to deliver conditioned air to individual rooms.

These flexible 56mm diameter tubes can snake throughout a building's structure much like electrical wiring.

In existing buildings this can be run between studs in walls, through cupboards, in the small spaces below floors and in 150mm ceiling voids.

The result is a discrete, full climate control heating and cooling system.

Small duct systems also circulate the air more effectively than traditional heating or cooling systems, providing even temperature levels with minimal variation, from floor to ceiling and wall to wall the temperature differential is no greater than 1C.

There is also the advantages of no cold spots, quick response times compared with radiators or underfloor heating, minimal drafts, air filtration capability, low noise levels and highly energy efficient operation.

They have the added benefit of providing heating, cooling and the option of fresh air all through the same system for full climate control including the removal of humidity.

They have the versatility to be used for just heating or cooling, if required, cooling can be added to a heating only system at a later stage.

They can also be zoned for close control of individual areas within a building.

sdHVAC systems can be compatible with almost any energy source and can link seamlessly to the latest air or ground source heat pumps to take advantage of renewable energy sources.

For installations where the cooling of a space is the only requirement, they can tie in with a refrigerant drive condensing unit that creates a cold refrigerant charge and therefore air conditioning.

They can be linked to VRF (variable refrigerant flow) and VRV (variable refrigerant volume) air conditioning systems to allow for variable temperatures in different parts of a building, at different times of the day.

Units can also be linked to any hot water source for heating, including traditional gas or oil fired boilers and wood pellet burners.

Applications include space cooling and heating, pre-heating domestic hot water and heat recovery.

The result is lower operating costs and higher energy efficiency than other types of heating or cooling systems.

They can also be linked to more than one energy source for even greater efficiency.

Today's small duct systems typically feature powerful 3-25kW units powered by the latest energy efficient EC fan motors which reduce energy consumption by around 30-50 per cent compared with AC fans.

Units can be mounted both vertically and horizontally.

The latest cooling coils provide high sensible cooling loads due to new innovative coil design and materials which means higher cooling duties to size of unit compared to the previous generation of unit.

Small duct systems take up around 1/4 of the space of a traditional heating or air conditioning system and can deliver up to 25kW of heating and cooling in the same space as a traditional 10kW system.

Quiet performance is achieved through the isolation of noise and vibration thanks to high performance closed cell insulation to the air handling unit itself.

Supply tubes are lined with sound dampening, spun bond nylon to deliver draft-free heating and cooling.

Invisible.AC cooling coils are typically twice as thick as traditional HVAC cooling coils.

The air moves through the coils more slowly in cooling mode, allowing the hot air from the space to stay on the cold cooling coil longer resulting in up to 30 per cent less humidity.

Heated or cooled air is delivered quietly and unobtrusively into rooms through small 56mm outlets or small slotted diffusers.

Customised outlet designs can be provided reflecting the ability of today's manufacturers and installers to create bespoke designs for individual projects.

The versatility of the latest small duct systems mean that they provide a real environmentally friendly solution that helps to meet the requirements of Part L of the Building Regulations and achieves a lower carbon footprint.

They can now also be linked to the latest home automation and BMS systems to provide a fully integrated approach to building services.

Today's providers and installers of small duct systems have learned from the 6000 installations that are already estimated to be running in the UK.

With their long life expectancy and extended warranties, sdHVAC systems are now truly coming into their own.

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