117230102
The role of thermostatic radiator valves for the control of space heating in UK social-rented households
This paper provides an analysis of the relationships between dwelling, household and motivation, behaviour and perception characteristics and thermostatic radiator valve (TRV) settings in living rooms (n = 187) and bedrooms (n = 159) in UK social housing. The work capitalises on primary data from a socio-technical household survey undertaken in Plymouth, UK during 2015, which was coupled with building audit data. The mean reported TRV setpoint temperatures in the living rooms and bedrooms were 23.4 °C and 21.9 °C, implying that occupants prefer cooler conditions in bedrooms. There were systematic variations according to dwelling, household, and motivation, behaviour and perception characteristics. In general, the setpoint temperatures in individual rooms were higher than the whole house thermostat setpoint temperature, implying that there may be a misunderstanding of the role of TRVs in the home heating system. The research could enable social housing providers, the government and commercial organisations to target energy efficiency measures (i.e. thermal upgrades) and social interventions (i.e. behaviour change) at those dwellings and households where their impact may be most beneficial. The results presented could also be used to improve the assumptions of zonal heating behaviour in energy models, which could result in more realistic predictions of the heating demands of social housing.
109100206
Central heating thermostat settings and timing: building demographics
Crucial empirical data (currently absent in building energy models) on central heating demand temperatures and durations are presented. These data are derived from the first national survey of energy use in English homes and includes monitored temperatures in living rooms, central heating settings reported by participants, along with building, technical, and behavioural data. The results are compared with model assumptions with respect to thermostat settings and heating durations. Contrary to assumptions, the use of controls did not reduce average maximum living room temperatures or the duration of operation. Regulations, policies, and programmes may need to revise their assumptions that adding controls will reduce energy use. Alternative forms of heating control should be developed and tested to ascertain whether their use saves energy in real-world settings. Given the finding that detached houses are heated for longer, these dwellings should be particularly targeted in energy-efficiency retrofit programmes. Furthermore, social marketing programmes could use the wide variation in thermostat settings as the foundation of a ‘social norm’ programme aimed at reducing temperatures in ‘overheated’ homes. Finally, building energy models that inform energy policies require firmer foundations in real-world data to improve policy effectiveness. Greater coordination of data collection and management would make more data available for this purpose. Sont présentées ici des données empiriques critiques (actuellement absentes des modèles énergétiques des bâtiments) concernant les températures demandées et les durées d'utilisation du chauffage central. Ces données proviennent de la première enquête nationale sur l'utilisation de l’énergie dans les foyers anglais et comprennent les températures contrôlées dans les salles de séjour, les réglages du chauffage central indiqués par les participants, ainsi que des données comportementales, techniques et relatives aux immeubles. Les résultats sont comparés aux hypothèses des modèles en ce qui concerne le réglage des thermostats et les durées de chauffage. Contrairement aux hypothèses, l'utilisation de dispositifs de régulation n'a réduit ni les températures maximales moyennes dans les salles de séjour, ni la durée de fonctionnement. Il serait peut-être nécessaire que les réglementations, les politiques et les programmes révisent leurs hypothèses selon lesquelles le fait d'ajouter des dispositifs de régulation réduira l'utilisation d’énergie. D'autres formes de régulation du chauffage devraient être développées et testées afin de vérifier si leur utilisation économise de l’énergie dans des cadres de vie réels. Etant donné la constatation que les maisons individuelles sont chauffées pendant plus longtemps, ces logements devraient être particulièrement ciblés dans les programmes de mise aux normes visant un meilleur rendement énergétique. De plus, les programmes de marketing social pourraient utiliser les grandes variations dans le réglage des thermostats comme base d'un programme de « norme sociale » visant à réduire la température dans les logements « surchauffés ». Enfin, il est nécessaire que les modèles énergétiques des bâtiments, qui ont une influence sur les politiques énergétiques, soient plus fermement basés sur des données réelles afin d'améliorer l'efficacité de ces politiques. Une plus grande coordination dans la collecte et la gestion des données permettrait de disposer de davantage de données à cette fin. Mots clés: modèle énergétique des bâtiments, chauffage central, systèmes de contrôle, température demandée, commandes du chauffage domestique, demande énergétique, comportement des habitants, réglage des thermostats
157049273
Space heating preferences in UK social housing: A socio-technical household survey combined with building audits
Abstract This paper provides an analysis of the relationships between dwelling, household, and motivation, behaviour and perception characteristics and winter heating setpoint temperatures (n = 111) and heating periods (n = 148 and 145) used in UK social housing. The work capitalises on primary data from a socio-technical household survey, undertaken in Plymouth, UK, during 2015, which was merged with building audit data collected by the social housing association managing the properties. The mean reported heating setpoint temperature was 20.9 °C and the average weekday and weekend day heating periods were 9.5 h and 11.2 h respectively. The results suggest that heating setpoint temperatures and periods vary greatly among UK social houses, but there are clear systematic variations according to dwelling, household, and motivation, behaviour and perception characteristics. The research could enable social housing providers, the government and commercial organisations to target energy efficiency measures (i.e. thermal upgrades) and social interventions (i.e. behaviour change) at those dwellings and households where their impact may be most beneficial. The results presented could also be used to better inform the assumptions of heating preferences in energy models, which could result in more realistic predictions of the space heating demands of social housing and the potential energy savings from refurbishment measures.
11884812
Driving factors for occupant-controlled space heating in residential buildings
Abstract Occupant behaviour has a large impact on the energy consumption of buildings, and therefore a better understanding can assist in many building-related applications, such as facility management, building performance simulation and occupant guidance. As occupant space-heating operation has a significant influence on the energy consumption of residential buildings in winter, an investigation of drivers for this behaviour was undertaken and the result is expressed in this paper. From the analysis, 27 drivers have been evaluated in previous behavioural studies and at present none of them can be identified confidently as having no influence. Following the identification of these key drivers, the modelling of occupant space-heating behaviour in traditional building performance simulation was reviewed and the result indicates that most of these factors are typically ignored when modelling space-heating operation in building performance simulation. It is concluded that future behavioural studies into the drivers discussed in this paper are needed to gain a better understanding and quantification of the impact of these factors on building energy use.
109686920
Heating patterns in English homes: Comparing results from a national survey against common model assumptions
Heating patterns and temperatures are among the most important determinants of English home energy use. Consequently, building stock models, widely used for informing UK energy policy, are highly sensitive to the assumptions they make on how occupants heat their homes. This study examined heating patterns in English living rooms and compared them to model assumptions. A time-series of winter spot temperature measurements was translated into statements of the heating system being on or off during weekdays and weekend days, and the heating demand temperature estimated. The analysis showed that weekdays and weekend days are far more similar than commonly assumed. Contrary to model assumptions, homes were frequently heated outside assumed heating hours and not all homes were heated at the same time or followed the same pattern. The estimated demand temperature was about 20.6 °C, and the average temperature during heating periods was about 19.5 °C, both lower than the commonly assumed 21 °C used in models. Significantly, variability between homes in demand temperature and hours of heating was substantial. The results indicate the need to revisit some assumptions made in building stock models, and to take account of variability between homes when aiming at predicting space heating demand for an individual home.
55833968
How are UK homes heated? A city-wide, socio-technical survey and implications for energy modelling
Abstract Understanding heating patterns in UK homes is crucial for energy policy formulation, the design of new controls and heating systems, and for accurate stock modelling. Metrics to describe heating patterns are proposed along with methods for calculating them from measured room temperatures. The patterns of heating in 249 dwellings in Leicester, UK are derived from measured hourly temperatures and a face-to-face socio-technical survey. Of the 93% of homes that were centrally heated, 51% were heated for two periods each day and 33% were heated for only one period per day. The mean winter temperature in the rooms varied from 9.7 °C to 25.7 °C. Heating patterns varied significantly and systematically depending on the age of the householders and their employment status. Compared to younger households and those in employment, households with occupants over 60 and those unable to work, turned their heating on earlier in the year, heated for longer each day, and heated to higher temperatures. The indoor temperatures were much lower than those customarily assumed by BREDEM-based energy models and patterns of heating were quite different. Such models could seriously and systematically misrepresent the benefits of energy efficiency measures to some sectors of society.
55144840
Statistical Analysis of Historical State-Level Residential Energy Consumption Trends
Developing an accurate picture of the major trends in energy consumption in the nation’s stock of residential buildings can serve a variety of national and regional program planning and policy needs related to energy use. This paper employs regression analysis and uses the PRISM (Princeton Scorekeeping Method) approach with historical data to provide some insight into overall changes in the thermal integrity of the residential building stock by state. Although national energy use intensity estimates exist in aggregate, these numbers shed little light on what drives building consumption, as opposing influences are hidden within the measurement (e.g., more appliances that increase energy use while shell improvements reduce it). This study addresses this issue by estimating changes in the reference temperatures that best characterize the existing residential building stock on a state basis. Improvements in building thermal integrity are reflected by declines in the heating reference temperature, holding other factors constant. Heating and cooling-day estimates to various reference temperatures were computed from monthly average temperature data for approximately 350 climatic divisions in the U.S. A simple cross-sectional analysis is employed to try to explain the differential impacts across states. Among other factors, this analysis considers the impact that the relative growthmore » in the number of residential buildings and the stringency of building energy codes has had on residential building energy use. This paper describes the methodology used, presents results, and suggests directions for future research.« less
112624863
Development of Dutch occupancy and heating profiles for building simulation
ABSTRACT Building simulations are often used to predict energy demand and to determine the financial feasibility of the low-carbon projects. However, recent research has documented large differences between actual and predicted energy consumption. In retrofit projects, this difference creates uncertainty about the payback periods and, as a consequence, owners are reluctant to invest in energy-efficient technologies. The differences between the actual and the expected energy consumption are caused by inexact input data on the thermal properties of the building envelope and by the use of standard occupancy data. Integrating occupancy patterns of diversity and variability in behaviour into building simulation can potentially foresee and account for the impact of behaviour in building performance. The presented research develops and applies occupancy heating profiles for building simulation tools in order create more accurate predictions of energy demand and energy performance. Statistical analyses were used to define the relationship between seven most common household types and occupancy patterns in the Netherlands. The developed household profiles aim at providing energy modellers with reliable, detailed and ready-to-use occupancy data for building simulation. This household-specific occupancy information can be used in projects that are highly sensitive to the uncertainty related to return of investments.
55108913
MODELLING OCCUPANTS' HEATING SET-POINT PREFFERENCES
Discrepancies between simulated and actual occupant behaviour can offset the actual energy consumption by several orders of magnitude compared to simulation results. Thus, there is a need to set up guidelines to increase the reliability of forecasts of environmental conditions and energy consumption. Simultaneous measurement of the set�괂Ġ point of thermostatic radiator valves (trv), and indoor and outdoor environment characteristics was carried out in 15 dwellings in Denmark in 2008. Linear regression was used to infer a model of occupants’ interactions with trvs. This model could easily be implemented in most simulation software packages to increase the validity of the simulation outcomes.
54744223
Heating behaviour in English homes: An assessment of indirect calculation methods
Heating behaviours, such as timer and room thermostat settings, are a key influencing factor in energy demand in homes. However they are difficult to measure directly in existing housing with standard heating systems and controls. To overcome this, several indirect methods have been developed in previous research which estimate heating behaviours using sensor measurements of temperatures and energy demands in the home. This work assesses seven of these heating behaviour indirect calculation methods through a comparative study based on sensor data recorded in 20 English homes over a five month period. The results show that methods based on room air temperatures estimate mean daily heating durations between 6.7 and 11.4 hours per day, based on radiator surface temperatures between 2.9 and 3.3 h per day and based on gas consumption for 4.4 h per day. Estimated thermostat setting based on peak whole house temperature ranged between 20.3 °C and 20.8 °C but a 5 °C temperature range was found when applying the methods to different room temperatures. Of the methods tested, the radiator surface temperature method was found to be the most appropriate for calculating heating behaviours over time and a set of guidelines for the future application of indirect heating behaviour calculation methods is provided. The findings highlight the need for future studies to directly measure heating behaviours in homes in order to further improve the development of indirect heating behaviour calculation methods.
22542712
Original research articleEnergy efficiency and the misuse of programmable thermostats: The effectiveness of crowdsourcing for understanding household behavior
Programmable thermostats are generally sold as energy-saving devices controlling heating and cooling systems, but can lead to energy waste when not operated as designed by the manufacturers. We utilized Amazon Mechanical Turk, an online crowdsourcing service, to investigate thermostat settings and behavior in households. We posted a survey and paid respondents to upload pictures of their thermostats to verify self-reported data. About 40% of programmable thermostat owners did not use programming features and 33% had programming features overridden. Respondents demonstrated numerous misconceptions about how thermostats control home energy use. Moreover, we found that 57% of households were occupied nearly all the time, limiting the potential energy savings. The study revealed flaws in self-reported data, when collected solely from traditional surveys, which raises concerns about the validity of current thermostat-related research using such data. “Ground truth” temperature data could now be available in homes with Internet-connected thermostats. Online crowdsourcing platforms emerge as valuable tools for collecting information that would be difficult or expensive to obtain through other means. Advantages over traditional surveys include low-cost, rapid design–implementation–result cycle, access to diverse population, use of multimedia. Crowdsourcing is more effective than alternative online tools due to easier recruitment process and respondents’ reputation system.
109855202
The reality of English living rooms - A comparison of internal temperatures against common model assumptions
Abstract Objective This study examines the extent that temperatures in English living rooms correspond to standard assumptions made in established UK building stock models. Methods Spot temperature measurements taken every 45 min over 92 winter days in 248 homes in England were analyzed and compared to the assumed thermostat setting of 21 °C inside and outside the assumed heating periods. Results Homes on average displayed lower internal temperatures during assumed heating periods and significantly shorter durations of heating to 21 °C than common models assume, with about 20% of homes never reaching the assumed demand temperature of 21 °C. Data showed a difference of only about 45 min in the duration of temperatures at or above the demand temperature for weekdays and weekends, contrary to the assumed difference of 7 h. Variability between homes was large. Conclusion These findings suggest that currently used standard assumptions of heating demand and heating duration do not accurately reflect the living room temperatures of dwellings in England. Practice implications Standard assumptions might have to be revised, in particular regarding the weekday–weekend differentiation. The prediction of internal temperature for a given home contains potential large error when using standard assumptions.
53554494
Targeting household energy-efficiency measures using sensitivity analysis
The Community Domestic Energy Model (CDEM) has been developed to explore potential routes to reduce carbon dioxide (CO2) emissions and the model is used to predict the CO2 emissions of the existing English housing stock. The average dwelling CO2 emissions are estimated as 5827 kgCO2 per year, of which space heating accounts for 53%, water heating for 20%, cooking for 5%, and lights and appliance for 22%. Local sensitivity analysis is undertaken for dwellings of different age and type to investigate the effect on predicted emissions of uncertainty in the model's inputs. High normalized sensitivity coefficients were calculated for parameters that affect the space heating energy use. The effects of the input uncertainties were linear and superposable, so the impact of multiple uncertainties could be easily determined. The results show that the accumulated impact on national CO2 emissions of the underperformance of energy-efficiency measures could be very large. Quality control of the complete energy system in new and refurbished dwellings is essential if national CO2 targets are to be met. Quality control needs to prioritize detached dwellings because their emissions are both the greatest and the most sensitive to all energy-efficiency measures. The work demonstrates that the uncertainty in the predictions of stock models can be large; a failure to acknowledge this can lead to a false sense of their reliability. Le Modèle d'Energie Domestique Communautaire (CDEM) a été développé afin d'explorer les voies possibles pour réduire les émissions de dioxyde de carbone (CO2) et ce modèle est utilisé pour prévoir les émissions de CO2 du parc bâti anglais existant. Les émissions de CO2 d'un logement moyen sont estimées à 5827 kg de CO2 par an, le chauffage des volumes en représentant 53%, le chauffage de l'eau 20%, la cuisine 5%, et l'éclairage et les appareils électroménagers 22%. L'analyse de la sensibilité locale est entreprise pour des logements d'âges et de types différents afin d'étudier l'incidence sur les émissions prévues de l'incertitude des données entrantes du modèle. Des coefficients de sensibilité normalisée élevés ont été calculés pour les paramètres qui affectent l'utilisation d'énergie pour le chauffage des volumes. Les effets des incertitudes des données entrantes étaient linéaires et superposables, de sorte qu'il a été possible de déterminer facilement l'incidence des multiples incertitudes. Les résultats montrent que les effets cumulés sur les émissions nationales de CO2 d'une performance inférieure aux attentes des mesures de rendement énergétique pouvaient être très importants. Le contrôle qualité de l'ensemble du système d'énergie dans les logements neufs et réhabilités est essentiel si l'on veut que les objectifs nationaux de CO2 soient atteints. Il est nécessaire que le contrôle qualité se donne pour priorité les logements individuels parce que ce sont leurs émissions qui sont à la fois les plus importantes et les plus sensibles à toutes les mesures de rendement énergétique. Ces travaux démontrent que l'incertitude dans les prévisions des modèles de parc de logements peut être importante; une incapacité à reconnaître cela peut conduire à une fausse impression quant à leur fiabilité. Mots clés: parc bâti modèle carbone émissions de dioxyde de carbone (CO2) domestique rendement énergétique modèle énergétique, logement
111281162
Predicted versus observed heat consumption of a low energy multifamily complex in Switzerland based on long-term experimental data
Abstract The “Solar Complex of Plan-les-Ouates” is a traditional multifamily building with some commercial and administrative areas. It was designed to consume a minimum amount of thermal energy by combining several renewable energy systems (1400 m 2 of solar roof, buried pipe and exhausted air heat exchangers) with an optimised envelope and electrical equipment. Initially predicted to consume 160 MJ/m 2 per year of gas, a gas energy use index (per unit heated floor area) of 246 MJ/m 2 per year was measured. The energy analysis of the building, based on a 3-year period of monitoring, brought up the most relevant points that explain this difference: the real conditions of utilisation (such as the interior temperature) and the real performance of the complete technical system are not taken into account in the theoretical value. Both technical and economical aspects of the renewable energy systems were analysed in detail. An important lesson learned from this experiment is that the energy concept of buildings must be simple and consistent and the complexity of the technical installations must be carefully managed from the design-stage to the exploitation. Detailed monitoring of innovative low-energy buildings is recommended to understand the possible discrepancies between theoretical and real heat consumption and to improve the transfer of new energy technologies to large-scale real constructions.
108642227
The impact of consumer behavior on residential energy demand for space heating
Besides technical parameters, consumer behavior is the most important issue with respect to energy consumption in households. In this paper, the results of a cross-section analysis of Austrian households are presented. The impact of the following parameters on residential energy demand for space heating have been investigated: (i) thermal quality of buildings; (ii) consumer behavior; (iii) heating degree days; (iv) building type (singleor multi-family dwellings). The result of this investigation provides evidence of a rebound-effect of about 15 to 30% due to building retrofit. This leads to the conclusion that energy savings achieved in practice (and straightforward the reduction in CO2 emissions) due to energy conservation measures will be lower than those calculated in engineering conservation studies. Straightforward, the most important conclusions for energy policy makers are: (i) Standards, building codes, respectively, are important tools to increase the thermal quality of new buildings; and (ii) Due to prevailing low energy prices, a triggering tool has to be implemented which may be rebates or loans.
54177211
Measuring the potential of zonal space heating controls to reduce energy use in UK homes: The case of un-furbished 1930s dwellings
Abstract 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’. Normalisation 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.
55224814
Potential energy savings achievable by zoned control of individual rooms in UK housing compared to standard central heating controls
Abstract Energy is wasted in domestic buildings when rooms that are heated are not occupied. Allowing those rooms to cool reduces the inside – outside temperature difference and therefore rate of heat loss, resulting in an energy saving. This suggests a cost effective way to upgrade an existing modern heating system, especially in older properties where other energy saving possibilities are limited. Assessing the savings achievable requires an analysis of a range of influencing factors, such as house type and age, location and occupancy patterns. Door opening has a major influence due to the impact on air exchange between heated and unheated zones in a house, so this was also considered. Annual simulations were carried out on dynamic models of the thermal and air flow interactions, for all combinations of influencing factors, to compare the potential energy savings of zoned versus non-zoned control. Savings of between 12% and 31% were obtained in the case of a semi-detached house model, and between 8% and 37% for a single storey bungalow. The largest percentage savings occurred in older properties, with interconnecting doors kept closed, and for the more intermittent types of occupancy. The average saving obtained for both house types was around 20%.
110634115
His, hers or both's? The role of male and female's attitudes in explaining their home energy use behaviours
Abstract Building energy research has historically overlooked the role of attitudes, instead focusing on building and socio-demographic influences. Even when attitudes are measured, usually, the attitudes of just one household member are measured even though household energy consumption is the result of actions of all household members. This research explored first whether attitudes could help explain heating usage and second whether the attitudes of a couple could explain more of the variability in heating behaviour than the attitudes of one partner. The attitudes towards home heating energy use (i.e. attitudes towards thermal comfort , economical with energy , industry and technology ' s role and individual ' s role ) of 128 English couples were used in this study. Together with building and socio-demographics, attitudes were examined to explain heating temperatures and durations, which were derived from temperature sensors placed in the homes in 2007–2008. The results showed that attitudes helped explain heating temperatures and durations, even when building and socio-demographic variables were controlled. Economical with energy was the most highly identified influence on heating behaviours, with thermal comfort a close second. In households that included a couple, combined attitudes of both partners explained heating usage behaviours more accurately than the attitudes of either male or female only.
154364208
Energy poor or fuel poor: What are the differences?
Energy poverty and fuel poverty are descriptors of problems of households' energy consumption, they are both distinct problems and have been addressed by many researchers, organizations and governments. Cross use of the terms of energy poverty and fuel poverty in published papers is common. As an accurate descriptor is the presupposition of research and policy development, especially for those who just started to pay attention to this issue, this paper compares the definitions, research priorities, status quo, and problems of these two concepts, and summarizes the relationship between them. The paper suggests that only when the research targets are households who are living in a cold climate and have difficulty in getting access to electricity or modern cooking facilities, and in supplying indoor heating with appropriate cost, the concepts of energy poverty and fuel poverty have the chance to be broadened and mutually integrated.
156026065
Getting the measure of fuel poverty: final report of the Fuel Poverty Review
The review confirms that fuel poverty is a serious national problem and shows that it is set to rise rapidly. It affects people with low incomes and energy costs above typical levels. It proposes a new way of measuring the problem, focused both on the number of people affected and the severity of the problem they face. Using the proposed measure: Nearly 8 million people in England, within 2.7 million households, both had low incomes and faced high energy costs in 2009 (the most recent year with available data). These households faced costs to keep warm that added up to £1.1 billion more than middle or higher income people with typical costs. The review’s central projection is that this “fuel poverty gap” – already three-quarters higher than in 2003 – will rise by a further half, to £1.7 billion by 2016. This means fuel poor households will face costs nearly £600 a year higher on average than better-off households with typical costs. The report also argues that: Fuel poverty exacerbates other hardship faced by those on low incomes, has serious health effects (including contributing to extra deaths every winter), and acts as a block to efforts to cut carbon emissions. The current official way of measuring it, based on whether a household would need to spend more than 10 per cent of its income on energy, is flawed, giving a misleading impression of trends, excluding some affected by the problem at some times and including people with high incomes at others. Interventions targeted on the core of the problem – especially those that improve the energy efficiency of homes lived in by people with low incomes – can make a substantial difference, but the impact of those planned to be in place by 2016 is only to reduce the problem by a tenth.
111027509
A national field survey of house temperatures
Information about temperatures in houses is of importance in assesing the value of various energy conservation measures and gives an indication of the standards of thermal comfort enjoyed by the occupants. In the present paper results are discussed of the most extensive survey of domestic dwelling temperatures to have been taken in the U.K. During February and March 1978, when the outside temperature was close to the average for the heating season, spot measurements of the wet- and dry-bulb temperatures were made in each room of 1000 homes nationwide. On the same occasion, an interview was conducted with an adult member of the household to obtain information on thermal comfort conditions and heating patterns. The globe temperature was measured in the room where the interview took place (usually the living-room). Interviews were conducted both during the daytime and in evenings, and at weekends as well as on weekdays. The mean of the living-room temperatures recorded was 18.3°C, mean kitchen temperature 16.7°C and mean temperature of the warmest bedroom 15.2°C. The average dwelling temperature was 15.8°C. The major sources of variance in temperature were the type and operation of the heating system, the dwelling age, household income, the time of day and geographical location. Household composition was a minor factor. The living-room temperature was relatively insensitive to the above-mentioned factors and had the appearance of being held at a level more or less independent of that in the rest of the dwelling. Centrally-heated houses ran 3°C warmer on average than non-centrally-heated houses. However, the difference in mean temperatures in the living-rooms between the two categories was only 1.5°C dry-bulb and 0.9°C globe temperature. Although strong correlations between a number of the explanatory variables, such as dwelling age and heating system type, means that a deeper analysis is required before a firm causal model can be proposed, the results provide an important new basis for assessing energy conservation options in domestic space heating.
110441845
Estimating space heating determinants: An analysis of Greek households
Abstract The purpose of this paper is to estimate the main determinants of households’ residential consumption for space heating in Greece employing cross-section data for 2003. In the empirical analysis household space heating consumption models are employed, using OLS, probit, tobit and quantile regression techniques. The results show that demographic and economic variables such as age of the respondent, family size and households’ annual income are suitable to explain differences towards oil consumption for space heating. In addition, the results suggest that dwelling's size and rate of occupancy are positively associated with the amount of oil that Greek households consumed in order to achieve a significant level of heat comfort for their house. By evaluating household's decision-making process with regard to space heating consumption we are able to propose an effective energy policy framework.
111282411
Domestic energy consumption—What role do comfort, habit, and knowledge about the heating system play?
Abstracts The aim of this study was to gain a better understanding of human factors potentially related to energy consumption in domestic households. In particular, the focus was on the meaning of comfort and comfort actions, barriers to and motivators for saving energy, and knowledge about the heating system. Data were collected using surveys, interviews, and monthly energy meter readings. The data of the main sample, social housing tenants, were supplemented by a sample of University staff to test if similar results would be obtained in two very different samples. Findings largely overlapped in the two groups. In summary, the main results were that (1) warmth was given most often as the meaning of comfort, (2) comfort practices were to a large extent defined as temperature-related actions with low energy use, (3) a deficit in the quality and quantity of instruction on how to use the heating system was reported, (4) being used to behaving in a certain way was seen as the most important barrier to behaviour change and was also related to actual energy consumption and self-reported energy consumption actions, and (5) willingness for behaviour change was greatest in order to save money.
110099980
How People Actually Use Thermostats
Residential thermostats have been a key element in controlling heating and cooling systems for over sixty years. However, today’s modern programmable thermostats (PTs) are complicated and difficult for users to understand, leading to errors in operation and wasted energy. Four separate tests of usability were conducted in preparation for a larger study. These tests included personal interviews, an on-line survey, photographing actual thermostat settings, and measurements of ability to accomplish four tasks related to effective use of a PT. The interviews revealed that many occupants used the PT as an on-off switch and most demonstrated little knowledge of how to operate it. The on-line survey found that 89% of the respondents rarely or never used the PT to set a weekday or weekend program. The photographic survey (in low income homes) found that only 30% of the PTs were actually programmed. In the usability test, we found that we could quantify the difference in usability of two PTs as measured in time to accomplish tasks. Users accomplished the tasks in consistently shorter times with the touchscreen unit than with buttons. None of these studies are representative of the entire population of users but, together, they illustrate the importance of improving user interfaces in PTs.
110673643
On the control of heating systems in the UK
This paper reviews current heating system control practice in the UK through surveys, computer simulation and experimental studies. It is evident from the survey results that both boiler and heat emitter controls in the UK are generally poor. Computer simulation of a heating system demonstrated that the use of poorly commissioned boiler controls and the use of thermostatic valves with limited flow control leads to buildings not maintaining the desired internal temperatures. This results in occupant discomfort when under-heating occurs and excess fuel consumption when over-heating occurs. Finally, an experimental study demonstrated that a newly developed boiler control algorithm can offer significant energy savings by controlling the boiler more appropriately and reducing the effect of poor thermostatic radiator valve use.