Fifty Years of PMV Model: Reliability, Implementation and Design of Software for Its Calculation

Abstract

In most countries, PMV is the reference index for the assessment of thermal comfort conditions in mechanically conditioned environments. It is also the basis to settle input values of the operative temperature for heating and cooling load calculations, sizing of equipment, and energy calculations according to EN 16798-1 and 16798-2 Standards. Over the years, great effort has been spent to study the reliability of PMV, whereas few investigations were addressed to its calculation. To study this issue, the most significant apps devoted to its calculation have been compared with a reference software compliant with EN ISO 7730 and the well-known ASHRAE Thermal Comfort Tool. It has been revealed that only few apps consider all six variables responsible for the thermal comfort. Relative air velocity is not considered by ASHRAE Thermal Comfort Tool and, finally, the correction of basic insulation values due to body movements introduced by EN ISO 7730 and EN ISO 9920 Standards has only been considered in one case. This implies that most software and apps for the calculation of PMV index should be used with special care, especially by unexperienced users. This applies to both research and application fields.Atmosphere 2020, 11, 49 2 of 14 buildings addressing IEQ, whereas EN 16798-2 explains how to use EN 16798-1 by specifying additional information as: (i) input parameters for building system design and energy performance calculations; (ii) methods for long term evaluation of the indoor environment; (iii) criteria for measurements which can be used if required to measure compliance by inspection; (iv) parameters to be used by monitoring and displaying the indoor environment in existing buildings. With reference to thermal comfort, EN 16798-1 suggests specific design ranges of operative temperature consistent with the desired level of environmental quality (see Table 1). Table 1. Temperature ranges for hourly calculation of cooling and heating energy for some indoor environment (Category II) according to EN 16798-1 and EN 16798-2 Standards [11,12]. Resultant insulation values I cl,r to be used [6] are 0.5 clo (cooling) and 1.0 clo (heating). Type of Building SpaceOperative Temperature Range for Heating ( • C) Operative Temperature Range for Cooling ( • C) Offices and spaces with similar activity (single offices, open plan offices, conference rooms, auditorium, cafeteria, restaurants, and classrooms). Sedentary activity: M = 1.2 met 20.0-24.0 23.0-26.0 Department store Standing-walking activity: M = 1.6 met 16.0-22.0 21.0-25.0

A Review and Insights for Eleven Years of Urban Microclimate Research Towards a New Egyptian ERA of Low Carbon, Comfortable and Energy-Efficient Housing Typologies

“…PMV was used when ENVI-met as an assessment tool that models all outdoor environment element, didn't have the PET yet. In the previous versions of ENVI-met it used an improved PMV for outdoor conditions after the work of Jendritzky and Nübler to account for the outdoor wind speed and all net wave radiation [47], however, much discussion can be found in the work of d'Ambrosio et al, for the calculation issues of the original Fanger PMV [48]. Considering that the three design suggestions have 8 cm grass and 15 m height Ficus elastica trees, the results of this study showed that the first design suggestion reduced the external thermal comfort with range 0.1-0.7 than the base case.…”

“…2 (DS2) is a newly designed clustered housing with adjusted aspect ratios and green infra over a new vehicular network, whereas DS3 is the same as DS2 but with higher albedo for building surfaces and asphalt roads. It has to be noted that curves in Figure 2 report modified PMV values according to Jendritzki and Nubler [47].…”

Development of a Bayesian based adaptive optimisation algorithm for the thermostat settings in agile open plan offices

“…The PMV value was calculated using the “calcPMV” function in R package “comf”, which applies the same calculations as Fanger [12] and ISO 7730 [20] . Alternative algorithms or softwares can be used to carry out the PMV calculation ( [9] and ASHRAE Standard-55 [3] , and a careful consideration of relative air velocity in the PMV calculation is required under high metabolic rates d’Ambrosio Alfano et al [8] , [9] ). We have assumed that the optimal air temperature T opt or PMV opt can be defined as the neutral condition at which a minimal percentage of people dissatisfied (PPD) can be achieved.…”

Analysis of Energy Consumption in Different European Cities: The Adaptive Comfort Control Implemented Model (ACCIM) Considering Representative Concentration Pathways (RCP) Scenarios

“…Furthermore, uncertainty in measurements must be also considered as well as in surveys of subjective occupant's evaluation [30]. On top of that, the recent advance in computational capacity has brought a catalogue of calculation tools for the PMV not only for personal computers, but also for smartphones, whose oversimplification in both the input data and the calculation procedure might lead to wrong results [31].…”

“…In contrast, adaptive comfort models have been developed in offices without HVAC systems (i.e., free-running offices), where occupants can freely interact with the building to achieve thermal comfort, either by opening or closing windows, changing their clothes or having cold drinks; in short, occupants are able to adapt, to a certain extent, to the internal ambient temperature [31,32].…”