Efficient heating controls#
For those keeping their existing heating systems
If you intend to replace your complete heating system very soon, you can skip this section, although parts of it might be relevant for your new system.
This is mostly about “wet” systems where hot water from a boiler is fed to radiators, but some of the comments also apply to electric heating and heat pumps.
A poor choice of heating controls can waste substantial amounts of energy - often enough to get a quick payback on investment in new controls. Unfortunately, installers and even architects can fail to think about how the building is used and make poor choices as a result. Some installers will say the controls can’t be changed just because they don’t want the hassle of wiring anything but the model they know.
There are two ways in which our controls waste heat.
The first is that installers are only required to ensure the control system meets any kind of minimum standard when they are making major system changes, like replacing a boiler. Heating controls have improved rapidly and many of us have boilers that pre-date the requirement to consider energy efficiency in which controls are installed.
The second is that installers often don’t put enough thought into what building users can do with the controls they can reach. Most controls allow building users to make changes to the heating to make themselves more comfortable. These changes will often also affect the comfort of other users - either people in different spaces at the same time, or future users of the building. Some controls allow permanent changes to the target room temperature or force the heating on or off all the time, overriding the time programme. That works in housing, where the residents can come to some kind of grudging agreement about how to operate the system. It can work in community buildings if there is very good communication and cooperation between user groups and the building managers. It’s more usual for user groups to work against each other, get frustrated, and then find their own, wasteful or unsafe ways of making themselves comfortable.
Not all controls will work with all boilers.
Some manufacturers will only work with their own controls and others use the “OpenTherm” standard and can be matched to a range of controls.
There aren’t as many options for old on/off boilers compared to modern, “modulating” boilers that can change the temperature of the hot water that the boiler supplies.
Ask us!
It’s very difficult to choose good controls, and we know as a community we need to develop a better understanding of what works. We encourage engineers to phone us after session 3, when they have a good understanding of what is happening in the building, for us to talk through what we know of the options. Scottish churches can also contact Eco-Congregation Scotland, which has in-house expertise on heating controls and shares our interest in developing case studies about what works in which situations. The Heating Hub has lots of information about controls aimed at housing, but their pages can be useful for us.