Energy performance of buildings. Calculation of energy needs for space heating and cooling using dynamic methods. General criteria and validation procedures

Monthly utilisation factors are the basis of many procedures for calculation of monthly heating or cooling requirements for buildings, notably in the procedure described in standard ISO 13790:2008 ‘Energy performance of buildings – Calculation of energy use for space heating and cooling’, which is widely used for the implementation of the Energy Performance of Buildings Directive in Europe. The procedures used to determine the values of the factors are invariably empirical rather than being derived from first principles, with the principal parameter being the ratio between monthly mean heat gains and monthly mean heat losses for the space in question. This article shows that this ratio is inherently insufficient to define the values and illustrates how months with similar values of the ratio can have different utilisation factors. It also shows that, if daily heating requirement is proportional to outdoor temperature, the key building parameter needed to determine the utilisation factor is the familiar base temperature. The base temperature can be expressed in terms of the monthly gain: loss ratio and the mean indoor and external temperatures: the day-to-day frequency distributions of outdoor temperature is also important. Finally, the article demonstrates that, for many situations, the ISO 13790 procedure and a linear model with residuals produce similar estimates of monthly heating requirement. However, this is not true towards the upper end of its observed range. In this situation, the linear model produces lower values for utilisation factors and correspondingly higher heating (and cooling) requirements. This effect is most marked when the mean indoor and outdoor temperatures are close or the space is well-insulated (causing a given heat gain to represent a higher potential temperature difference). Practical application: Monthly utilisation factors are the basis of many procedures for the calculation of monthly heating or cooling requirements for buildings, notably in the procedure described in standard ISO 13790:2008 ‘Energy performance of buildings – Calculation of energy use for space heating and cooling’, which is widely used for the implementation of the Energy Performance of Buildings Directive in Europe. This article shows that an alternative approach based on the concept of energy signatures, although producing very similar results in many situations, is a more robust and extendable basis for monthly heating and cooling energy demand calculations.

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The Effects of Occupancy and Solar Energy on Homes in the Pacific Northwest Constructed According to Improved Thermal Standards

ASME 2020 Heat Transfer Summer Conference ◽

10.1115/ht2020-9153 ◽

2020 ◽

Author(s):

D. R. Heerwagen ◽

K. Nicoliasen ◽

A. F. Emery

Keyword(s):

Pacific Northwest ◽

Thermal Response ◽

Solar Heating ◽

Space Heating ◽

Occupant Behavior ◽

Single Family ◽

Heating Season ◽

Heating And Cooling ◽

Energy Needs ◽

The Pacific

Abstract The space heating energy needed during the winter heating season in Seattle Washington, USA, was monitored over a 15 year period, 1987–2002. Single family residence houses were constructed to building code standards in force at the time of construction and two more to standards calling for envelopes with improved thermal resistance. Although space conditioning energy needs are strongly affected by occupant behavior, simulations generally ignore the temporal occupant behavior in estimating the energy needed for heating and cooling. Vigorous conservation tactics, which produce a thermal response that is highly transient, can lead to substantially different energy needs. No correlation could be established from the measured space heating when aggressive conservation made use of thermostat setback at every opportunity. In this paper we investigate the effects of occupant behavior and the effect of temporal solar heating of walls in the Seattle area for improved thermal construction.

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Thermal mass impact on energy performance of a low, medium and heavy mass building in Belgrade

Thermal Science ◽

10.2298/tsci120409182a ◽

2012 ◽

Vol 16 (suppl. 2) ◽

pp. 447-459 ◽

Cited By ~ 7

Author(s):

Bojan Andjelkovic ◽

Branislav Stojanovic ◽

Mladen Stojiljkovic ◽

Jelena Janevski ◽

Milica Stojanovic

Keyword(s):

Building Energy ◽

Energy Performance ◽

Office Building ◽

Energy Requirements ◽

Space Heating ◽

Thermal Mass ◽

Mass Concrete ◽

Building Energy Performance ◽

Heating And Cooling ◽

Space Cooling

Heavy mass materials used in building structures and architecture can significantly affect building energy performance and occupant comfort. The purpose of this study was to investigate if thermal mass can improve the internal environment of a building, resulting in lower energy requirements from the mechanical systems. The study was focused on passive building energy performance and compared annual space heating and cooling energy requirements for an office building in Belgrade with several different applications of thermal mass. A three-dimensional building model was generated to represent a typical office building. Building shape, orientation, glazing to wall ratio, envelope insulation thickness, and indoor design conditions were held constant while location and thickness of building mass (concrete) was varied between cases in a series of energy simulations. The results were compared and discussed in terms of the building space heating and cooling energy and demand affected by thermal mass. The simulation results indicated that with addition of thermal mass to the building envelope and structure: 100% of all simulated cases experienced reduced annual space heating energy requirements, 67% of all simulated cases experienced reduced annual space cooling energy requirements, 83% of all simulated cases experienced reduced peak space heating demand and 50% of all simulated cases experienced reduced peak space cooling demand. The study demonstrated that there exists a potential for reducing space heating and cooling energy requirements with heavy mass construction in the analyzed climate region (Belgrade, Serbia).

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