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HEAT RECOVERY VENTILATION (HRV)
OVERVIEW
• Introduction
• Types of mechanical ventilation
• Heat recovery ventilation(HRV)
• Why HRV’s?
• Components of HRV
• Working
• Advantages of HRV
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OVERVIEW(Cont..)
• Disadvantages of HRV
• Operating a HRV
• HRV maintenance
• Similar to HRV’s
• ERV’s vs HRV’s
• Conclusion
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INTRODUCTION
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Ventilating is the process of replacing air in any space to provide high indoor air quality
Methods - mechanical/forced and natural types
Windows serve as a fine strategy for natural ventilation in mild climatic conditions. But natural ventilation depends on local conditions & wind shading, which are beyond human control
INTRODUCTION( Contd...)
Also, According to US Environmental Protection Agency, indoor air pollution levels are five times higher than outdoors which demands - Mechanical Ventilation
Mechanical ventilation systems circulate fresh air using ducts and fans, rather than relying on airflow through small holes or cracks in a home’s walls, roof, or windows
The advantages of mechanical ventilation are better air quality, more control and improved comfort
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TYPES OF MECHANICAL VENTILATION
Supply Ventilation Systems—Hot or Mixed Climates
Balanced Ventilation Systems—All Climates
Heat Recovery Ventilation
(HRV)
Energy Recovery Ventilation (ERV)
Exhaust Ventilation Systems—Cold Climates
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HEAT RECOVERY VENTILATION (HRV)
Heat recovery ventilation( HRV) is an energy recovery ventilation system using equipment known as a heat recovery ventilator which employs a counter-flow heat exchanger between the inbound and outbound air flow
HRV provides fresh air and improved climate control, while also saving energy by reducing heating (and cooling) requirements
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WHY HRV’s?
PreferHRV’s
To reduce energy
consumption
Improved air quality
Provide architectur
al fancy without
compromising
ventilation
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COMPONENTS OF HRV
Fans
Filters
Defrost mechanisms or Pre-heater
Operating controls
Ducts
Heat exchange core
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COMPONENTS OF HRV(Contd..)
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WORKING
Intake Air
Air from atmosphere is taken via ducts
Air is filtered
Heat Exchange Core
Moves through insulated ducts
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WORKING(Contd..)
Fresh Air To Building
Air reaches circulating fan
Fan distributes air throughout the building
Stale Air From Building
The air is collected
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WORKING(Contd.…)
Heat Exchange Core
Transfers the heating or cooling effect of stale air to the fresh air intake for next cycle
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WORKING(Contd..)
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www.thestovestore.net PC
ADVANTAGES OF HRV
Continuous supply of fresh air
Energy efficient ventilation
Condensation elimination
Comfort
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ADVANTAGES OF HRV(Contd..)
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• 1) Continuous Supply of Fresh Air– Filtered fresh air is circulated throughout day and
night
– Most people spend over 80% of their time indoors, 50% of all illnesses are either caused by, or aggravated by poor indoor air quality
– The HRV System continuously removes stale moist air creating a healthy environment
ADVANTAGES OF HRV(Contd..)
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• 2) Energy Efficient Ventilation– A HRV systems save money and reduce energy for
heating by re-using heat that is lost via standard extract systems
– A HRV is designed to operate continuously at low rate to minimize electrical energy consumption
ADVANTAGES OF HRV(Contd..)
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• 3) Condensation Elimination– Water vapour will be removed as it is produced
– As a result there is no moisture condensation which causes rot, damp, condensation or mould growth
– No fungal growth in bathrooms
ADVANTAGES OF HRV(Contd..)
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• 4) Comfort – Comfort levels are superior in a house fitted with a
Heat Recovery Ventilation system
– Irrespective of weather conditions, draught free balanced ventilation is provided all the time
– Extra security when windows are closed
DISADVANTAGES OF HRV
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Needs regular maintenance
Filters need cleaning or replacing every 6–12 months.
High installation cost
Not much beneficial in hot weather conditions
OPERATING A HRV
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• Controls– Allows user to adjust the rate of ventilation and
humidity level to certain extend– Depending upon models & installation, controls
may be located on HRV itself or in rooms– Pollutant sensors are also installed– Can turned off HRV, when required
HRV MAINTENANCE
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Clean or replace air filters
Clean the heat-exchange core
Inspect ductwork
Arrange for annual servicing
Clean the condensate drain and pan
SIMILAR TO HRV’s
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An alternative system called energy recovery ventilation (ERV) works in a similar way as heat recovery ventilators
Transfers moisture from the outgoing airstream to the incoming air
It’s the disadvantage of ERV, which are covered up by the HRV’s
HRV’s vs. ERV’s
HRV core
ERV core
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CONCLUSION
Provides fresh air and improved climate control
Most efficient in saving energy
All buildings require source of fresh air, the need for HRVs has become obvious
The best technology currently available for reducing radon levels
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REFERENCES
• Solutions for Energy Efficient and Sustainable Heating of Ventilation Air: A Review A. Žandeckis*, K. Kļaviņa, M. Dzikēvičs, V. Kirsanovs and G. Žogla,Journal of Engineering Science and Technology Review 8 (3) (2015) 98-111
• Akbari K., Oman R.(2013).”Impacts of Heat Recovery Ventilators on Energy Savings and Indoor Radon in a Swedish Detached House.”WSEAS Transactions on Environment & Development, 9(1),2224-3496.
• Natural Resources Canada’s Office of Energy Efficiency(2012), “Heat recovery ventilators”,HTTP://WWW.HOUSING.YK.CA/PDF/HRV.PDF
• Akbari et.al (2013) "Impacts of heat recovery ventilators on energy savings and indoor radon level", Management of Environmental Quality: An International Journal, Issue 5,Volume 24, Page 682 – 694
• Juha Jokisalo , Jarek Kurnitski , Mika Vuolle , Antti Torkki(2003) ”Performance of Balanced Ventilation with Heat Recovery in Residential Buildings in a Cold Climate”The International Journal of Ventilation,2(4) 223 -236
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• Ambrose Dodoo, Lief Gustavasson, Roger Sathre (2011) “Primary energy implications of ventilation heat recovery in residential buildings” Energy and Buildings, 43(7) 1566 – 1572
• Efficiency “International journal of ventilation 6 Olli Seppanen (2008)” Ventilation Srtategies for Good Indoor Air Quality and Energy(4)297-306
• P.Wargocki(2013) “The Effects of ventilation in homes on health” International journal of ventilation 12(2)101-118
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