The idea for a single, common standard for communication in the domestic heating sector between heating controls and central heating appliances – boilers and air heaters – has been mooted for many years and indeed has been growing in popularity across Europe, but has only recently begun to make its mark seriously here in the UK.
OpenTherm is a non-manufacturer dependent system of communication currently utilised predominantly between modulating HVAC heating appliances and room thermostats. It consists of a communication protocol and an interface specification. OpenTherm utilises an established technology combining simple installation procedure with high functionality and future expansion possibilities.
The OpenTherm Association is intending to introduce the OpenTherm protocol more widely in the UK and has launched an initial three-year communication process to raise awareness of the protocol, its benefits to the heating industry as a whole and to manufacturers and installers in particular. The OpenTherm protocol facilitates digital boiler modulation and as a result, load compensation requirements are met. The growth of the use of the OpenTherm protocol across the UK would offer huge innovation potential. Looking ahead, a large installed base of OpenTherm compatible products could facilitate the implementation of a range of new solutions that could improve energy use, reduce the carbon footprint of a heating installation and reduce its total cost of ownership. Typical potential examples could see the increase in home automation and the availability of remote diagnostics for domestic installations. The OpenTherm Association recognises that in order to establish the OpenTherm protocol, it needs to effectively communicate and illustrate ‘what’s in it for me’ benefits to those manufacturing the equipment and those installing it in homes up and down the country.
The OpenTherm Association already has a number of members signed up to work with it to introduce a wider acceptance of OpenTherm as a standard in the UK – manufacturers of boilers and controls that have already evaluated the OpenTherm protocol’s compatibility with their systems – well-known names in the sector including Ideal Boilers, Honeywell Resideo, Danfoss, SALUS, ESi and Schneider Electric. Many other familiar names in the UK sector – major companies in Europe with an influence in the UK marketplace – may well combine to see the acceptance of the OpenTherm protocol speeding up in the UK marketplace. Recognising the common sense in developing a common use ‘Open’ system here in the UK, the protocol also has the support of industry bodies HHIC and BEAMA, which are committed to supporting OpenTherm’s wider introduction here.
The basic function that every OpenTherm controller must provide is the communication of the heat requirement – the control setpoint – to the heating appliance. This heat requirement is calculated by the controller based on the difference between the set temperature and the desired one, or another form of control such as outside temperature control. The OpenTherm protocol also supports many other non-compulsory functions offering the manufacturer the opportunity to develop multiple product variants.
Manufacturers who are interested in developing and producing OpenTherm compatible products can approach the OpenTherm Association secretariat to obtain a data sheet, free of charge, by completing the request form on the new OpenTherm website.