Determining of the role of ventilation in residential energy demand reduction using a heat-balance approach

Abstract

Ventilation in domestic buildings can have a significant impact on energy consumption but it is notoriously difficult to quantify, requiring physical test methods that are cumbersome and costly to apply. Energy demand reduction analyses routinely neglect the impact of ventilation and so offering well balanced advice for specific households is not possible. This paper describes a simple steady-state, heat-balance calculation method that is supplemented with monitoring data to model the effectiveness of reducing ventilation rates to minimum standards for individual homes. A key step is to determine the daily mean air change rate and the method is shown to yield plausible estimates that can then be used to establish the impact on energy demand. The benefits of the approach include improved energy demand dissargregation, customised energy demand reduction assessment and offers a means to underpin the development of better models of ventilation for building performance analysis.

Energy Modelling and Calibration of Building Simulations: A Case Study of a Domestic Building with Natural Ventilation

“…Model 1 was used removing the gas consumption measurement as a heat gain in the house. Then, a heating system was considered, where the energy demand was obtained introducing the set-point at 18.7 • C, as suggested in previous work [4]. The remaining data for window position and infiltration remains the same as in Model 1.…”

“…Methods that can provide better estimates of air change rates on a house by house basis are valuable when understanding energy demand reduction measures in the home [4]. The most significant energy losses occur through the envelope, due poor insulation, ventilation, and infiltration.…”

“…The quantification of ventilation rates has been a matter of interest in research over the last century, however there is little work evaluating how purge ventilation and behavioral patterns affect whole house energy consumption [4]. Although other measurement techniques, such as use of tracer gas, and steady-state analysis of CO 2 concentrations [8], have been developed, the main drawbacks are usually the cost and on-site implementation.…”

“…Although other measurement techniques, such as use of tracer gas, and steady-state analysis of CO 2 concentrations [8], have been developed, the main drawbacks are usually the cost and on-site implementation. Also, these measurement methods limit the estimation of infiltration to a specific moment and are unable to characterize a wide range of building operating conditions usually required in modelling and simulation [4,9].…”

“…This paper combines the modelling tool TRNSYS with monitoring data to generate hourly mean air change rate (ACR) estimates. The results are compared to published work [4] by the authors, to gain confidence in the method. The paper describes the approach, studies ACR in natural ventilated buildings, and the impact of ACR on energy demand.…”