Domestic Heating ‘Revolution’ Awaiting Next Generation Sensors

A radical solution for home heating could dramatically transform the way in which we heat our homes as well as reduce energy costs if a recent proposal by a recently retired engineer, Colin Guppy formerly of the United Kingdom Atomic Energy Authority (UKAEA) and British Energy, gains traction. In his paper, ‘Domestic Heating: Use of a Fast Response System (FRS)’, Guppy argues the standard method of heating homes is wasteful of energy. “Household rooms are often occupied for short periods of time of between 10 and 30 minutes. So heating them over long periods of time is harmful to the wallet and to the environment,” he said. Guppy’s proposition is to replace, when appropriate, the traditional method of heating the home with shorter periods of fast response warming using a combination of heaters, controls and insulation.

Currently, domestic heating is largely achieved through central heating from a single gas boiler. This supplies hot water to a number of radiators distributed around the house, centrally controlled by a single thermostat and timer. The clear advantage of this system is that it is simple to use and install. However, there are in-built complexities. These include the need to supply hot water to two separate systems; the radiators and the hot water taps. A lot of the heat output from radiators is also lost by convection. And the control system's thermostat, which is usually placed in a central location, is largely insensitive to the air temperature requirements in different rooms.

Fast Response as the Solution

Home heating needs differ from room to room and Guppy argues that a fast response system is an ideal solution. In the living room, the essential need is to warm up each room when it is occupied or is shortly going to be occupied, and for no longer. In the bedroom, heating is really only required when preparing for bed and when getting up. The bathroom and kitchen have a similar requirement. “Central heating radiators are far too slow for this, electrical fan heaters come closest to meeting the need,” says Guppy. And for this, a really effective thermostat is required, as are pre-set and remote controls.

“Remote control (local wireless) has to be effective, confidence in its performance being a major issue,” he said. Consumers need to be confident that when a fan-heater is switched 'on' or 'off', remotely, the switching actually occurs to avoid long periods of unintended heating. They will also need to be assured that the switch device is capable of handling the electrical load changes in the heater without problems. For Guppy, the ultimate hope is that radiators could eventually be disconnected and as a result, an existing gas-fired combination boiler could be replaced by a simpler tap-water heating only type boiler.

Need for New Sensors

However, for a fast response system of the type envisaged by Guppy to work a number of developments will first need to take place. These include a broadly recommended method for how this insulation should be installed; fan-heater specifications to meet the needs of an FRS; timing and remote control electronics; prototype FRS fan-heaters; and then trials to assess all-round acceptability. And he concedes that for the most part, the current range of sensors that are available on the market are not adequate for a fast response heating system.

“A really effective thermostat is required and the performance of built-in thermostats on currently available fan-heaters is often a little disappointing.” Wirelessly controlled, plug-in, switches are available currently, but it would appear, for the most part, that their electrical rating, often 10 Amps, only just covers the 8.33 Amps electrical load for something like a 240 V, 2 kW heater. Their failure rate also seems quite high.  A properly designed, robust, switch is therefore required. The remote for these switches will ideally also need to be redesigned so that the current state of the switch, whether ‘on’ or ‘off’, is fed back to the remote.

Outlook

Examples of non-contact temperature thermostats that are currently on the market include the Nest Thermostat E. This contains an algorithm that ‘learns’ your heating habits over time; the Tado Smart Thermostat that features ‘geofencing’, which tracks the proximity of your mobile and therefore when you're on the way home; British Gas’ Hive heating control; the Ecobee4 that works with both Amazon Alexa and Google Assistant; the Netatmo home weather station that is controlled via the free Android and iOS apps; the Honeywell Lyric T6/T6R that can be controlled either via its touchscreen or via the free Honeywell Lyric smartphone app. It also features built-in geofencing; the Honeywell Evohome; the Heatmiser NEO; and the Drayton Wiser Thermostat system.