Evaluation of the Workplace Environment in the UK, and the Impact on Users’ Levels of Stimulation

The purpose of this study is to evaluate a number of recently completed workplaces in the UK. The first aim is to assess the impact of various aspects of the workplace environment on users’ levels of stimulation. The body of previous research undertaken into the workplace environment, identified the aspects to be investigated. Samples of employees from the sixteen businesses were surveyed to determine their perceptions of the workplaces. The results were entered into a regression analysis, and the most significant predictors of perceived stimulation identified. The data also revealed a dramatic reduction in staff arousal levels from mornings to afternoons. Thus, there is a second aim to determine whether changes to significant aspects of the workplace environment during the day can counteract the reduction in users’ stimulation. Two further workplaces were studied to enable changes to be made over a 12-week period. A sample of employees completed questionnaires, and semi-structured interviews revealed the reasons behind the results. It was found that provision of artwork, personal control of temperature and ventilation and regular breaks were the most significant contributions to increasing stimulation after lunch; while user choice of layout, and design and décor of workspaces and break areas, were the most significant aspects at design stage

Accounting for refrigeration heat exchange in energy performance simulations of large food retail buildings

Heat exchange between chilled food storage and conditioned spaces in large food retail stores is not currently required as part of design stage regulatory compliance energy performance models. Existing work has identified that this exchange has a significant impact on store energy demand and subsequently leads to unrealistic assessment of building performance. Research presented in this article uses whole building dynamic thermal simulation models that are calibrated against real store performance data, quantifying the impact of the refrigeration driven heat exchange. Proxy refrigerated units are used to simulate the impact of these units for the sales floor areas. A methodology is presented that allows these models to be simplified with the aim of calculating a realistic process heat exchange for refrigeration and including this in thermal simulation models; a protocol for the measurement of chilled sales areas and their inclusion in the building models is also proposed. It is intended that this modelling approach and the calculated process heat exchange inputs can be used to improve the dynamic thermal simulation of large food retail stores, reduce gaps between predicted and actual performance and provide more representative inputs for design stage and regulatory compliance energy calculations

Thermal responses of single zone offices on existing near-extreme summer weather data

There have been a number of attempts in the past to define “near extreme” weather for facilitating overheating analysis in free running buildings. The most recently efforts include CIBSE latest release of Design Summer Year (DSY) weather using multiple complete weather years and a newly proposed composite DSY. This research aims to assess how various single zone offices respond to these new definitions of near extreme weathers. Parametric studies were carried out on single zone offices through which four sampling sets of models were employed to examine the thermal responses of dry bulb temperature, global solar radiation & wind speed collectively. London weather data from 1976 to 1995 were used and the overheating assessments were made based on CIBSE Guide A & BS EN 15251. The research discovers that solar radiation and wind both influence the predicted indoor warmth with solar radiation has obvious stronger impacts than wind. No perfect correlation was found from observation and Spearman’s rank order analysis on the ranks between the weather warmth and the predicted indoor warmth. The ranks made using multiple weather parameters show better correlation than some of the dry bulb temperature only metrics. The research also discovers that the Test Reference Year weather behaves warmer than expected. It is also found that a single complete year can not represent the near-extreme consistently and there is no evidence a composite DSY is better statistically. These findings support the notion of using multiple complete warm weather years for overheating assessments

Glazing daylighting performance and Trombe wall thermal performance of a modular façade system in four different Portuguese cities

This paper reports on a new façade system that uses passive solutions in the search for energy efficiency. The differentials are the versatility and flexibility of the modules, which are important advantages of the system. The thermal performance of Trombe walls and glazings and the daylighting performance of glazing were the key aspects analyzed in the results. Computational simulations were accomplished for the thermal performance of different arrangements of the modules with DesignBuilder software. The glazing daylighting performance was studied by means of Ecotect and Desktop Radiance programs and compared with the transmittance curves of glazings. Occupancy profile and internal gains were fixed according to the Portuguese reality for both studies. The main characteristics considered in this research were the use of two double glazings, four different climates in Portugal and one and two Trombe walls in the façade. The results show an important reduction in the energy consumption with the use of Trombe walls and double self-cleaning glazing in the façade, which also presented better daylighting performance.Author Helenice M Sacht benefited from a scholarship granted by Erasmus Mundus ISAC - Improving Skills Across Continents to perform her research work at University of Minho, from which resulted this article

Evaporative cooling systems to improve internal comfort in industrial buildings

Several studies were carried out to determine how hot or cold environments can affect task performance and can influence productivity. Usually, HVAC plants are exactly designed in order to guarantee comfortable internal conditions inside built environments, but not all kind of buildings are equipped with a heating or cooling plant, like for example, some industrial buildings. These buildings are often characterized by high internal thermal loads. For those buildings the ability of different plant configurations to improve indoor thermal conditions was considered taking into account the influence of several parameters, like weather conditions, internal gains, thermal transmittance, ventilation air flow rate, etc. Simulation results are compared in terms of energy savings and thermal comfort. \ua9 2017 The Author(s)

Quantifying the aggregate thermal performance of UK holiday homes

In the UK, there are approximately 330,000 holiday homes spread across a large number of mainly privately owned sites. These homes are often sited in exposed locations, are poorly insulated and are generally heated using expensive fuels, such as electricity or LPG. There is also a lack of empirical evidence available on the in situ energy performance of these homes. Consequently, it is not possible, given the existing evidence base, to determine whether these homes suffer from the same scale of building fabric thermal ‘performance gaps’ (between assumed and realised in situ performance) that have been documented for new build UK housing. This paper presents the results obtained from undertaking detailed in situ thermal fabric tests on five new holiday homes. Whilst sample size reported here is small, the results indicate that a ‘performance gap’ exists for all of these homes. Results obtained indicate that this gap appears narrower than that documented for new build UK housing. The results also suggest that the scale of the ‘gap’ may be more a consequence of the way in which the design intent of these homes has been determined, i.e. a ‘prediction gap’

Estimating the Background Ventilation Rates in New-Build UK Dwellings – is n50/20 appropriate?

In the UK, a rule of thumb applied to air permeability is commonly employed when estimating background ventilation rates from pressurisation test data. However, this may lead to significant errors in estimating the infiltration rates in UK new-build dwellings, resulting in poor estimation of the dwellings in-use energy and CO2 emissions, and the adoption of ventilation strategies leading to either unacceptable indoor air quality or unnecessary energy consumption. In this paper, a preliminary investigation into the applicability of the rule of thumb is undertaken. Background ventilation rates in four new-build dwellings in the UK are determined using the tracer-gas decay method and also the pressurisation (blower-door) method coupled with both the conventional n50/20 and (in the UK) q50/20 rule of thumb, and Sherman’s modified rule of thumb, which takes into account other building-related factors. The conventional method over-estimated the air-change rate in two of the dwellings and under-estimated it in the other two dwellings. The modified rule of thumb produced comparable results for two of the dwellings, but significantly underestimated the air-change rate in the other two dwellings. These results suggest that more work needs to be done to devise appropriate climate and building-related correction factors for the UK

Thermal and sound insulation performance assessment of vacuum insulated composite insulation panels for building façades

Composite insulation panels (CIPs) currently used in building façades require significant design changes e.g. increased thickness to realise higher thermal and sound insulation performance. This study deals with the manufacturing and characterisation of smart façade panels for achieving higher thermal and sound insulation dual characteristics in one panel without a significant increase in thickness. Prototype panels were manufactured using vacuum insulation core (VIC) combined with mass loaded vinyl (MLV) layers. Thermal transmission and weighted sound reduction index (R_w) was experimentally measured in the laboratory. The results were compared with a control panel made with extruded polystyrene (XPS) core. The VIC panel showed a 51% improvement in the centre of panel U-value compared to control XPS core panel of the same thickness. Integrating the two MLV layers inside of aluminium skins either side of the vacuum insulation panel led to 3dB improvement in R_w from 32 dB to 35 dB which could be further improved by optimising the MLV layer positioning in the CIP and better bonding between the MLV and the vacuum insulation panel. This shows that vacuum insulation core panels combined with MLV offers a solution to achieve smart building façade with excellent thermal and sound insulation performance

Investigating the productivity of office workers to quantify the effectiveness of climate change adaptation measures

Copyright © 2013 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Building and Environment . Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Building and Environment Vol. 69 (2013), DOI: 10.1016/j.buildenv.2013.07.010The impacts of climate change pose many threats to our current way of life. However, the current mitigation agenda has not yet produced the carbon emission reductions needed implying that some level of adaptation will be required. For buildings this is likely to mean either drastic changes to architecture, occupant behaviour or the increased use of artificial cooling to maintain thermal comfort in the future. The capital cost of sustainable buildings is often perceived to be higher than for conventional buildings and there is little incentive to employ sustainable building adaptations over air-conditioning type solutions, making future reductions in carbon emissions unlikely. In this paper we investigate contributing factors to worker productivity in an attempt to justify the perceived cost of sustainable adaptations. Then as a proof of concept we estimate the potential savings that could be achieved by applying two simple adaptations to an office building to produce a more comfortable environment. It is hoped that this consideration of loss of productivity and its causes will aid not only in the choice of useful adaptation decisions, but also a consideration of payback periods will help persuade building commissioners of their value and overcome the perceptions about sustainable buildings

Suspended timber ground floors: measured heat loss compared with models

There are approximately 6.6 million dwellings in the UK built before 1919, predominantly constructed with suspended timber ground floors whose thermal performance has not been extensively investigated. The results are presented from an in-situ heat-flow measuring campaign conducted at 27 locations on a suspended timber ground floor, and the estimated whole-floor U-value compared with modelled results. Findings highlight a significant variability in heat flow, with increased heat loss near the external perimeter. In-situ measured-point U-values ranged from 0.54 ± 0.09 Wm−2 K−1, when away from the external wall perimeter, to nearly four times as high (2.04 ± 0.21 Wm−2 K−1) when near the perimeter. The results highlight the fact that observing only a few measurements is likely to bias any attempts to derive a whole-floor U-value, which was estimated to be 1.04 ± 0.12 Wm−2 K−1 and nearly twice that derived from current models. This raises questions about the validity of using such models in housing stock models to inform retrofit decision-making and space-heating-reduction interventions. If this disparity between models and measurements exists in the wider stock, a reappraisal of the performance of suspended timber ground floors and heat-loss-reduction potential through this element will be required to support the UK’s carbon-emission-reduction targets