Performance evaluation of a mechanically ventilated heat recovery (MVHR) system as part of a series of UK residential energy retrofit measures

White, Jennifer; Gillott, Mark; Wood, Christopher J.; Loveday, Dennis L.; Vadodaria, Keyur

doi:10.1016/j.enbuild.2015.09.059

Cited by 14 publications

(10 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 4 illustrates variations in the mean CO2 concentration in steady-state condition triggered by alteration of the air flow rate. The figure compares values of the CO2 concentration obtained by the numerical model with those yielded by Equation (14). The figure shows a good agreement between numerical results and analytical ones.…”

Section: Validation Of the Numerical Modelsupporting

confidence: 59%

“…Although several studies in the literature have analysed the performance of HRV systems [14,15], fewer attempts have been made to assess the efficacy of a coupled HRV-heater system in providing desirable IEQ in residential buildings, including air quality and thermal comfort condition. The present study aims to fill this gap by investigating the performance of a HRV system integrated with a low-temperature radiator in terms of IEQ inside a retrofitted dormitory room.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Study on Indoor Environmental Quality in a Room Equipped with a Combined HRV and Radiator System

Jahanbin

Semprini

2020

Sustainability

View full text Add to dashboard Cite

Heat recovery ventilation (HRV) systems can be integrated with an additional air heater in buildings with low energy demand in order to cover space heating demand. The employment of coupled HRV-heater systems is, therefore, gaining increasing interest for the improvement of the indoor environmental quality (IEQ), as well as the reduction of ventilation energy loss. The present paper analyses the efficacy of a HRV system, coupled with a low-temperature radiator, in satisfying the IEQ indices inside a retrofitted dormitory room. A computational fluid dynamic (CFD) model based on the finite volume method is established to investigate IEQ characteristics including indoor air quality and thermal comfort condition. The presented CFD code provides a practical tool for a comprehensive investigation of the IEQ indices in spaces employing a coupled HVAC system. In an analysis of indoor air quality, parameters such as age of the air, air change efficiency, and ventilation efficiency in removal of gaseous contaminants, namely VOCs and CO2, are evaluated. The results obtained by the numerical model allow addressing the interaction between HRV and radiator systems and its effects on airflow field. The results show the decrease of the indoor operative temperature with increment of the supply air flow rate, which is mainly due to the decreased thermal efficiency of the HRV system. The obtained results indicate that, while higher ventilation rates can significantly decrease the age of the air and gaseous contaminants level, at the same time, it would cause a local discomfort in some parts of the room.

show abstract

Section: Validation Of the Numerical Modelsupporting

confidence: 59%

Section: Introductionmentioning

confidence: 99%

Numerical Study on Indoor Environmental Quality in a Room Equipped with a Combined HRV and Radiator System

Jahanbin

Semprini

2020

Sustainability

View full text Add to dashboard Cite

show abstract

“…Research suggests that achieving the benefits of MVHR is currently challenging due to issues spanning installation, commissioning and performance. 10,14,[25][26][27] Secondly, it would be instructive to evaluate the effectiveness of existing building regulations that attempt to link airtightness to ventilation type -such as the Scottish approach in Figure 6 -to assess whether matching airtightness category and ventilation type works in practice. The range approach used in Scotland and built upon in the suggestion in this paper is only one possible approach to strengthening the link.…”

Section: Discussionmentioning

confidence: 99%

The relationship between airtightness and ventilation in new UK dwellings

Crawley

Wingfield

Elwell

2018

Building Services Engineering Research and Technology

View full text Add to dashboard Cite

The UK's Air Tightness Testing and Measurement Association competent persons scheme collects pressure test data and metadata from the majority of new build dwellings in the UK. This article uses the dataset to investigate the importance of the ventilation strategy in airtightness design and construction. Design and measured airtightness were tested for association with declared ventilation strategy. It was found that ventilation strategy makes a statistically significant difference to airtightness; however, this difference is too small to be practically relevant. Properties with mechanical ventilation and heat recovery (MVHR) were shown to have a mean designed air permeability only 0.46 m 3 /m 2 h lower than naturally ventilated dwellings. Seventy-three per cent of homes with MVHR have design airtightness greater than or equal to 5 m 3 /m 2 h and 17% of naturally ventilated dwellings have design airtightness less than 5 m 3 /m 2 h. We discuss how current design is not maximising the CO 2 , cost and air quality benefit of each ventilation strategy. A new approach to regulatory compliance is proposed, which explicitly links the designed airtightness and chosen ventilation system. It is suggested that compliance could then be achieved using a set of airtightness ranges linked to appropriate ventilation strategies. This could be expected to result in reduced energy consumption and carbon emissions for new build homes compared to the current approach and would also potentially lead to better outcomes for occupants in terms of indoor air quality. Practical application: Analysis of a large database of the airtightness of new UK dwellings found that ventilation strategy makes very little difference to airtightness design. For dwellings with MVHR, the results suggest that infiltration levels are too high to maximise the energy savings; for naturally ventilated homes, there may be air quality issues. Coupling airtightness design and ventilation strategy can reduce a dwelling's energy demand and can support achieving the required energy performance rating.

show abstract

“…It works 165 well in an airtight house, however, for a property with poor airtightness, or if the system is 166 not correctly installed or commissioned, it can potentially increase energy use (White, 2016).…”

mentioning

confidence: 99%