Fan coil unit equipment has evolved steadily over the past few decades into a highly developed and effective means of providing air conditioning for a building. As with any technology there is the potential for serious problems if products are applied or installed incorrectly, thus making professional guidance essential.
Recent legislation concerning energy reduction and carbon emissions further highlights the importance of correct design, installation, commissioning and maintenance to achieve efficient air conditioning and avoid energy waste.
This Technical Memorandum sets out to describe all aspects of fan coil unit technology and provides manufacturers, designers, site personnel and operators a comprehensive guide.
Note 2: An important standard relating to filters is referenced in this title, BS EN 779: 2012 'Particulate air filters for general ventilation. Determination of the filtration performance'. This replaced the previous 2002 edition, but is now itself withdrawn. It was superseded in July 2018 by BS EN ISO 16890 (in 4 parts).
The new classifications are based on expanded tests for particulates and there is no 1-to-1 relationship with the EN 779-based classes. There are implications for both new and existing HVAC systems and potentially for guidance on natural ventilation. In due course, CIBSE guidance will be updated to reflect this change but in the mean time, you should note it.
This Eurovent document provides a useful summary of the changes: https://eurovent.eu/sites/default/files/field/file/Eurovent%20REC%204-23%20-%20Selection%20of%20EN%20ISO%2016890%20rated%20air%20filter%20classes%20-%202017.pdf.
Contents:
1. Introduction to fan coil unit technology
2. Fan coil unit principles
2.1 Introduction
2.2 Water-side fan coil units
2.3 Air-side fan coil units
2.4 Casing
2.5 Fans
2.6 Coils
2.7 Filters
2.8 Fan coil unit plenums
2.9 Controls
2.10 Energy considerations
3. Design of fan coil unit installations
3.1 Introduction
3.2 Ceiling mounted, ducted chassis units
3.3 Vertically mounted and cased fan coil units
3.4 Sizing of fan coil units
3.5 Air terminal devices
3.6 Pipework systems
3.7 Controls
3.8 Acoustics
4. Selection of fan coil units
4.1 Introduction
4.2 Type of unit
4.3 Performance parameters
4.4 Commercial considerations
4.5 Specifications
5. Installation
5.1 Health and safety
5.2 Delivery and storage
5.3 Fitting of units
5.4 Ductwork connections
5.5 Pipework connections
5.6 Condensate removal
5.7 Electrical and controls wiring
5.8 False ceilings
6. Site commissioning
6.1 Pre-commissioning
6.2 Commissioning the air distribution system
6.3 Commissioning the water system
6.4 Condensate drainage system
6.5 Control system commissioning
6.6 Acoustic performance
6.7 Thermal output
6.8 Witnessing
6.9 Documentation and handover
7. Servicing and maintenance
7.1 Introduction
7.2 Servicing
7.3 Maintenance and repair
7.4 Energy performance inspections
8. Laboratory testing
8.1 Introduction
8.2 Air-side criteria
8.3 Water-side criteria
8.4 Acoustic performance
8.5 Electrical and control systems
8.6 Product safety testing
8.7 Test facilities
8.8 Testing rationale
References
Acknowledgements
Principal author: Mike Price (Biddle Air Systems Ltd.)
HEVAC Working Group: Eddie Browning (Eaton-Williams Group Ltd.); Ken Butcher (CIBSE); Troy Chambers (Actionair); Dave Cogger (Caice Acoustic Air Movement Ltd.); Mike Duggan (HEVAC Association); John Lightfoot (TEV Ltd.); Peter Lowther (Ability Projects Ltd.)
Contributors: David Lush; John Middleton (Samson Controls); José Ortiz (BRE); Chris Parsloe (Parsloe Consulting Ltd.); John Sands (BSRIA); Mike Smith (BSRIA)
Other acknowledgements: Phil Casey (Carver Climate Systems Ltd.); Peter Graydon (Computair Ltd.); Roger Hitchin (BRE); Susan Holmes (Warwick Dynamics Ltd.)