Measuring and modelling the energy demand reduction potential of zonal space heating controls in a UK home
Arash Beizaee, Loughborough University
Background:
According to the current patterns of heating in UK houses, energy is considerably wasted through unsuitable heating patterns. Clear examples of this could be leaving the heating system fully on when nobody is at home or heating the whole house to maintain the same temperatures while only a fraction of the home is in use (particularly at night). In addition, since most of the UK homes are centrally heated, energy is wasted by overheating certain spaces of the house to make up for temperature variations through different parts of the house.
Digital Technology (DT) provides new opportunities to monitor and control households’ energy use. DT enables the application of Zonal Control (ZC) for the heating which means that the heating can be controlled for distribution in spaces only at the time they are occupied and to the level needed even remotely and via a mobile phone. However, at the moment, there is very little idea of how much (if any) energy can be saved using these DT devices and systems and in which households they might work best.
Aim:
To determine the potential for energy demand reduction from space heating in UK homes which could be achieved by applying zonal heating controls.
Objectives:
To conduct a thorough literature review to find out the space heating controls which are currently being used in UK homes, heating control specifications according to the Building Regulations and the current technological potential for employing zonal space heating controls. The literature review also investigates how government’s standard assessment procedure (SAP) and dynamic building thermal modelling (i.e. EnergyPlus) could deal with zonal space heating and its energy saving implications.
To characterize, quantify, test and set up the experimental facilities required to conduct zonal heating trials in two identical test houses including digital control devices, energy & environmental monitoring equipment and occupancy simulation appliances.
To construct models of the test houses in SAP and EnergyPlus in order to predict the potential energy demand reduction from applying zonal heating control strategies before any experimental work is carried out. The initial predictions will then be tested against experimental work.
To conduct a series of zonal heating trials in the two test houses during winter while occupancy is simulated to investigate the space heating energy requirements and indoor air temperatures when zonal heating is established compared to when conventional space heating control strategies are applied.
To collect, refine and analyse the data collected through the zonal heating experiments to compare with the predictions from dynamic thermal models. The data will then be used in order to develop calibrated dynamic models of the test houses in which the model predictions of indoor temperatures and energy use could closely match with the data collected through the experiments.
To use the calibrated dynamic models in order to predict the energy demand reduction from applying zonal heating controls for different house types, building envelopes, occupant behaviours and geographical locations while realistic constraints in achieving the maximum savings will be applied.
Methodology:
Space heating trials will be conducted in two identical semi-detached houses over the winter 2013-14. The presence of occupants will be simulated and indoor environment and energy consumption will be measured. Conventional space heating control will be compared with zonal heating control strategies.
The data from these tests will be used to develop calibrated dynamic models using building simulation software. The models will then be used to extrapolate the test results and quantify the potential energy demand reduction from zonal heating control for houses with different built form, occupancy patterns and climates.
Anticipated outcomes:
A better understanding of current domestic heating controls and an updated review of available systems.
Quantification of the potential energy reduction that could be achieved from different UK households by using digital control devices to apply zonal control to their space heating.
Verification of the current modelling techniques for predicting inter-zone heat transfer in houses.
A pair of thoroughly characterised test houses for future research and consultancy.
Related article on BBC: (http://www.bbc.co.uk/news/business-25779937?SThisFB)
Outputs
Conference poster
The potential of zonal heating control to reduce energy demand in UK homes
Poster at LOLO annual colloquium 2013
Journal paper (first author)
Measuring the Potential of Zonal Space Heating Controls to Reduce Energy use in UK homes: the case of un-furbished 1930s dwellings
Click here to view outputs
A matched pair of 1930s semi-detached houses, in original condition and un-refurbished in terms of energy efficiency, were employed to measure the energy savings that might result from the use of zonal space heating control (ZC). The houses were adjoined and had the same synthetic, yet realistic, occupancy schedule, the same new central heating system, and were exposed to the same weather conditions. In one house the space heating was controlled conventionally (CC) according to minimum requirements in UK Building Regulation Part L1B for existing dwellings, whereas in the other house ZC was used to heat the rooms only when they were ‘occupied’. Over an 8-week winter test period, the house with ZC used 11.8% less gas despite 2.4 percentage points drop in average daily boiler efficiency. Although zonal control reduced the mean indoor air temperature of the whole house by 0.6 °C, it did not reduce the average air temperature in rooms during the hours of active ‘occupancy’. Normalization and extrapolation of the results shows that, compared to CC, ZC could reduce annual gas demand for space heating by 12% in most regions of the UK, and that ZC would be a more effective energy efficiency measure in homes in the cooler, more northerly regions of the UK.