Weather Compensation

Weather compensation is a valuable way to improve modern heating systems efficiency.

Nearly all houses in the UK have very basic heating controls. The boiler is instructed to turn on by the room thermostat and runs at its maximum temperature , and it then switches off when the thermostat says it is warm enough.  

These problems are exasperated by several things

1. The positioning of the room thermostat. We tend to put room thermostats in areas which have large radiators such as living rooms
2. Radiators are generally oversized.
3. Boiler is oversized

The net result of this is that the system suffers greatly from overheating, the boiler will continually turn on and off (cycling), and the system will run very inefficiently and at times make the heating uncomfortable.

Types of weather compensation:

Outdoor Sensor

By installing an outdoor sensor , heating systems can adjust the system controls to compensate for changes in outdoor temperature automatically. As the weather gets colder the system works harder and produces more heat to your radiators, and as the weather warms up the system reduces the temperature. The system therefore runs more consistently feeding heat into the building gradually and efficiently over a longer period of time.

Opentherm - Intelligent weather compensation 

The 3rd generation NEST utilises the local weather station data to inform it of outdoor temperatures. When connected and properly configured to a boiler which can utilise opentherm, the boiler can then control the heat going into your radiators in much the same way as the outdoor sensor.

Opentherm - An open source method of communication between boilers and controls. Note not all manufacturers support this and supply there own controls

The key benefits to weather compensation are:

• Energy is fed into the building gradually over a period of time using the equipment as it is designed to be used.
• The boiler will modulate and run at a lower, efficient rate (eg Driving at efsteady speed
• The boiler fires less often and reduces cycling which is a major cause of inefficiency and premature failure in traditional central heating systems.
• It maintains the building at a steady temperature and provides the occupants with increased levels of comfort.
• There is no need to turn off your heating system at all. The heating will come on as required by the outdoor temperature. This means that on a cool, late summer evening the heating will automatically come on to provide some heat, and on a warm spring day the heating will not switch on at all.
• Finally, the effect of running the system with weather compensation means a potential saving of up to 15% on your fuel bills. 

Excerpt from https://www.isoenergy.co.uk/more-information/weather-compensation-for-heating-controls