Improving the performance of heat valve ventilation system: A study on the provided thermal environment

Joanna Polak, Alireza Afshari, Parastoo Sadeghian, Cong Wang, Sasan Sadrizadeh

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The current study presents and evaluates the performance of two types of supply air terminal devices applied in a heat valve ventilation (HVV) system with regard to the provided thermal environment in a room heated and ventilated by the HVV system. To that end, air temperature and air velocity patterns and local thermal discomfort due to draught were studied both experimentally and numerically. Using numerical simulations, parametric analysis was carried out for investigating the provided indoor thermal environment for a wider range of boundary conditions. The considered parameters included the influence of cold vertical surfaces, supply airflow rate and temperature, and room heating energy demand. The results showed that both of the applied air terminal devices could avoid temperature stratification within the occupied zone. The maximum air temperature difference between 0.1 and 1.8 m above the floor was 2.1 °C when using a circular valve placed in the external wall below the window and 2.6 °C in the case when the air was supplied through three nozzles located in the wall opposite to the window in the upper part of the room. In general, placing the air terminal device below the window provided more uniform air temperature distribution and contributed to the prevention of downdraught caused by a cold window surface. The outcomes of this study are relevant to selecting and designing ventilation and air heating systems for low-energy buildings.
Original languageEnglish
JournalBuilding and Environment
Volume164
ISSN0360-1323
DOIs
Publication statusPublished - 2019

Fingerprint

Ventilation
ventilation
heat
air
Air
Airports
performance
air temperature
heat pump
heating
Heating
Temperature
supply
airflow
Hot Temperature
Nozzles
Temperature distribution
stratification
energy shortage
boundary condition

Keywords

  • Air heating
  • Air terminal device
  • Thermal environment
  • Air distribution
  • Temperature stratification
  • Draught rate

Cite this

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title = "Improving the performance of heat valve ventilation system: A study on the provided thermal environment",
abstract = "The current study presents and evaluates the performance of two types of supply air terminal devices applied in a heat valve ventilation (HVV) system with regard to the provided thermal environment in a room heated and ventilated by the HVV system. To that end, air temperature and air velocity patterns and local thermal discomfort due to draught were studied both experimentally and numerically. Using numerical simulations, parametric analysis was carried out for investigating the provided indoor thermal environment for a wider range of boundary conditions. The considered parameters included the influence of cold vertical surfaces, supply airflow rate and temperature, and room heating energy demand. The results showed that both of the applied air terminal devices could avoid temperature stratification within the occupied zone. The maximum air temperature difference between 0.1 and 1.8 m above the floor was 2.1 °C when using a circular valve placed in the external wall below the window and 2.6 °C in the case when the air was supplied through three nozzles located in the wall opposite to the window in the upper part of the room. In general, placing the air terminal device below the window provided more uniform air temperature distribution and contributed to the prevention of downdraught caused by a cold window surface. The outcomes of this study are relevant to selecting and designing ventilation and air heating systems for low-energy buildings.",
keywords = "Air heating, Air terminal device, Thermal environment, Air distribution, Temperature stratification, Draught rate",
author = "Joanna Polak and Alireza Afshari and Parastoo Sadeghian and Cong Wang and Sasan Sadrizadeh",
year = "2019",
doi = "https://doi.org/10.1016/j.buildenv.2019.106338",
language = "English",
volume = "164",
journal = "Building and Environment",
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Improving the performance of heat valve ventilation system: A study on the provided thermal environment. / Polak, Joanna; Afshari, Alireza; Sadeghian, Parastoo; Wang, Cong; Sadrizadeh, Sasan.

In: Building and Environment, Vol. 164, 2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Improving the performance of heat valve ventilation system: A study on the provided thermal environment

AU - Polak, Joanna

AU - Afshari, Alireza

AU - Sadeghian, Parastoo

AU - Wang, Cong

AU - Sadrizadeh, Sasan

PY - 2019

Y1 - 2019

N2 - The current study presents and evaluates the performance of two types of supply air terminal devices applied in a heat valve ventilation (HVV) system with regard to the provided thermal environment in a room heated and ventilated by the HVV system. To that end, air temperature and air velocity patterns and local thermal discomfort due to draught were studied both experimentally and numerically. Using numerical simulations, parametric analysis was carried out for investigating the provided indoor thermal environment for a wider range of boundary conditions. The considered parameters included the influence of cold vertical surfaces, supply airflow rate and temperature, and room heating energy demand. The results showed that both of the applied air terminal devices could avoid temperature stratification within the occupied zone. The maximum air temperature difference between 0.1 and 1.8 m above the floor was 2.1 °C when using a circular valve placed in the external wall below the window and 2.6 °C in the case when the air was supplied through three nozzles located in the wall opposite to the window in the upper part of the room. In general, placing the air terminal device below the window provided more uniform air temperature distribution and contributed to the prevention of downdraught caused by a cold window surface. The outcomes of this study are relevant to selecting and designing ventilation and air heating systems for low-energy buildings.

AB - The current study presents and evaluates the performance of two types of supply air terminal devices applied in a heat valve ventilation (HVV) system with regard to the provided thermal environment in a room heated and ventilated by the HVV system. To that end, air temperature and air velocity patterns and local thermal discomfort due to draught were studied both experimentally and numerically. Using numerical simulations, parametric analysis was carried out for investigating the provided indoor thermal environment for a wider range of boundary conditions. The considered parameters included the influence of cold vertical surfaces, supply airflow rate and temperature, and room heating energy demand. The results showed that both of the applied air terminal devices could avoid temperature stratification within the occupied zone. The maximum air temperature difference between 0.1 and 1.8 m above the floor was 2.1 °C when using a circular valve placed in the external wall below the window and 2.6 °C in the case when the air was supplied through three nozzles located in the wall opposite to the window in the upper part of the room. In general, placing the air terminal device below the window provided more uniform air temperature distribution and contributed to the prevention of downdraught caused by a cold window surface. The outcomes of this study are relevant to selecting and designing ventilation and air heating systems for low-energy buildings.

KW - Air heating

KW - Air terminal device

KW - Thermal environment

KW - Air distribution

KW - Temperature stratification

KW - Draught rate

U2 - https://doi.org/10.1016/j.buildenv.2019.106338

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JO - Building and Environment

JF - Building and Environment

SN - 0360-1323

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