scholarly journals Impacts on Indoor Thermal Comfort and Heating Energy Use in Hellenic Dwellings from Occupant Behavioral Reactions

2021 ◽  
Vol 11 (14) ◽  
pp. 6254
Author(s):  
Elena G. Dascalaki ◽  
Constantinos A. Balaras
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Energy Savings ◽  
Local Heating ◽  
Economic Recession ◽  
Heating System ◽  
Building Stock ◽  
Heating Systems ◽  
Indoor Thermal Comfort ◽  
Energy Audits

In an effort to reduce the operational cost of their dwellings, occupants may even have to sacrifice their indoor thermal comfort conditions. Following the economic recession in Greece over recent years, homeowners have been forced to adapt their practices by shortening heating hours, lowering the indoor thermostat settings, isolating spaces that are not heated or even turning off their central heating system and using alternative local heating systems. This paper presents the results from over 100 occupant surveys using questionnaires and walk-through energy audits in Hellenic households that documented how occupants operated the heating systems in their dwellings and the resulting indoor thermal comfort conditions and actual energy use. The results indicate that the perceived winter thermal comfort conditions were satisfactory in only half of the dwellings, since the actual operating space heating periods averaged only 5 h (compared with the assumed 18 h in standard conditions), while less than half heated their entire dwellings and only a fifth maintained an indoor setpoint temperature of 20 °C, corresponding to standard comfort conditions. Mainstream energy conservation measures include system maintenance, switching to more efficient systems, reducing heat losses and installing controls. This information is then used to derive empirical adaptation factors for bridging the gap between the calculated and actual energy use, making more realistic estimates of the expected energy savings following building renovations, setting prudent targets for energy efficiency and developing effective plans toward a decarbonized building stock.

scholarly journals Thermal Comfort and Energy Use with Local Heaters

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2912
Author(s):  
Jan Kaczmarczyk ◽  
Joanna Ferdyn-Grygierek
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Human Subjects ◽  
Local Heating ◽  
Internal Heat ◽  
Thermal Conditions ◽  
Heating System ◽  
Local Conditions ◽  
Heating Systems ◽  
Low Efficiency

This paper presents the investigation of a local heating system consisting of three heating mats incorporated within a sedentary workplace. Thermal comfort and individual power settings for the heating mats were studied in experiments with 41 human subjects. Experiments were performed in a climate chamber at two operative temperatures: 16 and 18 °C. Results showed that local heating systems improved occupants’ comfort and were able to create acceptable thermal conditions under both temperatures. The power settings identified were used to study the applicability of heating mats in an industrial hall. Multi-variant analysis of energy consumption for heating was carried out using an ESP-r (Environmental Systems Performance–Research) simulation program. The analysis results demonstrate that in some cases, the installation of local heating mats in industrial halls may reduce energy usage compared to having to heat the entire hall. However, the benefits depend on numerous parameters. Local heating is most advantageous when installed in halls with a small number of workstations, small internal heat gains, and low-efficiency central heating systems. In reality for the satisfactory implementation of local heating systems for a particular application, it is advised to perform analysis for the specific local conditions. In order to improve the effectiveness of local heating systems, an advanced heating control strategy should be considered.

scholarly journals Quantifying the performance of a passive deaerator in a gas-fired closed loop domestic wet central heating system

2016 ◽  
Vol 38 (3) ◽  
pp. 269-286
Author(s):  
David Johnston ◽  
David Glew ◽  
Dominic Miles-Shenton ◽  
Moaad Benjaber ◽  
Richard Fitton
Keyword(s):  
Energy Use ◽  
Closed Loop ◽  
Energy Savings ◽  
Low Cost ◽  
Heating System ◽  
Test Method ◽  
Heat Output ◽  
Heating Systems ◽  
Central Heating ◽  
The Uk

In the UK, approximately 16% of the energy use can be attributed to domestic wet central heating systems. Government financial support and advances in technology have led to boilers becoming more efficient and a range of technologies are now available that claim to be able to improve the efficiency of domestic wet central heating systems. One such low cost technology is a passive deaerator. This article presents the results obtained from installing a passive deaerator on the closed loop of a gas-fired wet central heating system, under controlled conditions in the Salford Energy House. The results indicate that although marginally less heat output was required from the boiler when the passive deaerator was operating, these savings are more or less out weighted by the boiler short cycling more frequently. Consequently, the overall reduction is gas consumption achieved by utilising the passive deaerator device is only of the order of 0.5%; this scale of savings may just be a consequence of measurement noise. The implications are that although a marginal benefit may be attributed to these products, if short cycling takes place, then these savings may become insignificant. Practical application: This article describes a test method that has been used to quantify the energy savings that could be achieved by installing a passive deaerator on the closed loop of a wet central heating system. Although the results indicate that the energy savings associated with using such a device are likely to be marginal, the test method described could be used to test a range of other devices that claim to improve the performance of domestic wet central heating systems, to directly compare before and after performance.

scholarly journals Is It Possible to Supply Norwegian Apartment Blocks with 4th Generation District Heating?

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 941 ◽  
Author(s):  
Øystein Rønneseth ◽  
Nina Holck Sandberg ◽  
Igor Sartori
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
District Heating ◽  
Heating System ◽  
Indoor Climate ◽  
Building Stock ◽  
Electricity Grid ◽  
Heating Systems ◽  
Energy Focusing ◽  
Temperature Levels

Direct electricity is widely used for heating purposes in Norway, leading to significant strain on the electricity grid during the heating season. Conversion to 4th generation district heating (4GDH) is an effective method for reducing the need for large investments in the electricity grid, while simultaneously improving the energy efficiency of district heating systems. This article evaluates the possibility of reducing the supply temperature in existing Norwegian apartment blocks by improving the thermal envelope and reducing the temperature levels for the heating system. The analysis is based on simulations in IDA ICE (IDA Indoor Climate and Energy) focusing on whether the reduced supply temperature guarantees thermal comfort in the building, considering the coldest room with a heating setpoint of 22 °C. Based on a recommended minimum acceptable indoor temperature of 19 °C from the Norwegian building regulations (TEK), it should be possible to lower the radiator supply temperature from 80 to 60 °C for apartment blocks newer than 1971. For older buildings, an “intermediate” renovation is necessary to maintain temperatures above 19 °C, however, a “standard” renovation is recommended to ensure thermal comfort and improve the energy efficiency of the building stock.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

scholarly journals Importance of Behavioral Adjustments for Adaptive Thermal Comfort in a Condominium with HEMS System

2020 ◽  
Vol 15 (3) ◽  
pp. 163-170
Author(s):  
Rajan KC ◽  
Hom Bahadur Rijal ◽  
Masanori Shukuya ◽  
Kazui Yoshida
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Energy Use ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Outdoor Environment ◽  
Adaptive Behaviors ◽  
Outdoor Air ◽  
Indoor Thermal Environment ◽  
Indoor Thermal Comfort

The energy use in residential dwellings has been increasing due to increasing use of modern electric appliances to make the lifestyle easier, entertaining and better. One of the major purposes of indoor energy use is for improving indoor thermal environment for adjusting thermal comfort. Along with the use of passive means like the use of mechanical devices, the occupants in any dwellings use active means such as the use of natural ventilation, window opening, and clothing adjustment. In fact, the use of active means when the outdoor environment is good enough might be more suitable to improve indoor thermal environment than the use of mechanical air conditioning units, which necessarily require electricity. Therefore, the people in developing countries like Nepal need to understand to what extent the occupants can use active means to manage their own indoor thermal comfort. The use of active means during good outdoor environment might be an effective way to manage increasing energy demand in the future. We have made a field survey on the occupants’ adaptive behaviors for thermal comfort in a Japanese condominium equipped with Home Energy Management System (HEMS). Online questionnaire survey was conducted in a condominium with 356 families from November 2015 to October 2016 to understand the occupants’ behaviors. The number of 17036 votes from 39 families was collected. The indoor air temperature, relative humidity and illuminance were measured at the interval of 2-10 minutes to know indoor thermal environmental conditions. The occupants were found using different active behaviors for thermal comfort adjustments even in rather harsh summer and winter. Around 80% of the occupants surveyed opened windows when the outdoor air temperature was 30⁰C in free running (FR) mode and the clothing insulation was 0.93 clo when the outdoor air temperature was 0⁰C. The result showed that the use of mechanical heating and cooling was not necessarily the first priority to improve indoor thermal environment. Our result along with other results in residential buildings showed that the adaptive behaviors of the occupants are one of the primary ways to adjust indoor thermal comfort. This fact is important in enhancing the energy saving building design.

scholarly journals Development and Evaluation of Occupancy-Aware HVAC Control for Residential Building Energy Efficiency and Occupant Comfort

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5396
Author(s):  
Christina Turley ◽  
Margarite Jacoby ◽  
Gregory Pavlak ◽  
Gregor Henze
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Energy Savings ◽  
Prediction Models ◽  
Smart Devices ◽  
Building Energy Efficiency ◽  
Occupancy Models ◽  
Probabilistic Prediction ◽  
Hvac Control ◽  
Occupancy Prediction

Occupancy-aware heating, ventilation, and air conditioning (HVAC) control offers the opportunity to reduce energy use without sacrificing thermal comfort. Residential HVAC systems often use manually-adjusted or constant setpoint temperatures, which heat and cool the house regardless of whether it is needed. By incorporating occupancy-awareness into HVAC control, heating and cooling can be used for only those time periods it is needed. Yet, bringing this technology to fruition is dependent on accurately predicting occupancy. Non-probabilistic prediction models offer an opportunity to use collected occupancy data to predict future occupancy profiles. Smart devices, such as a connected thermostat, which already include occupancy sensors, can be used to provide a continually growing collection of data that can then be harnessed for short-term occupancy prediction by compiling and creating a binary occupancy prediction. Real occupancy data from six homes located in Colorado is analyzed and investigated using this occupancy prediction model. Results show that non-probabilistic occupancy models in combination with occupancy sensors can be combined to provide a hybrid HVAC control with savings on average of 5.0% and without degradation of thermal comfort. Model predictive control provides further opportunities, with the ability to adjust the relative importance between thermal comfort and energy savings to achieve savings between 1% and 13.3% depending on the relative weighting between thermal comfort and energy savings. In all cases, occupancy prediction allows the opportunity for a more intelligent and optimized strategy to residential HVAC control.

scholarly journals Assessment of Using Heat Pumps for Heating in Mobile Homes: A Case Study from North Carolina

2009 ◽  
Vol 4 (3) ◽  
pp. 135-142
Author(s):  
Hussein Abaza
Keyword(s):  
North Carolina ◽  
Thermal Comfort ◽  
Low Income ◽  
Field Measurements ◽  
Heating System ◽  
Heat Pumps ◽  
Mobile Homes ◽  
Indoor Thermal Comfort ◽  
The North ◽  
Low Income Families

This paper presents the results of “Upgrade and Save”, a program to upgrade the standard electric furnaces and air-conditioning units in Mobile Homes for energy-efficient heat pumps. This program is implemented in North Carolina, USA and pays about $700 through a rebate provided by the North Carolina State Energy Office to the Mobile Homes' owners. The goal of this project is to subsidize low-income families by lowering their heating cost in the winter as well as improving their homes' indoor thermal comfort. More than 300 mobile homes have participated in this program. Field measurements, meter readings of the actual electrical consumption, and annual building energy simulation were used to measure the dollar saving and the indoor thermal comfort improvement in the mobile homes after the heating system upgrade. This research proved that the dollar saving of using the heat pump for heating in mobile homes ranges from $51 to $128 annually.

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