scholarly journals Heat Loss for a Run-Around Hybrid Ventilation System with Heat Recovery

2016 ◽  
Author(s):  
H. Davidsson ◽  
Ricardo Bernardo
Keyword(s):  
Heat Loss ◽  
Heat Recovery ◽  
Ventilation System ◽  
Hybrid Ventilation

scholarly journals Yearly Heat Loss Analysis of a Heat Recovery Ventilator Unit for a Single-Family House in St. John’s, NL, Canada

2019 ◽  
Vol 3 (5) ◽  
Author(s):  
Rabbani Rasha ◽  
M. Tariq Iqbal
Keyword(s):  
Energy Consumption ◽  
Heat Loss ◽  
Heat Recovery ◽  
Ventilation System ◽  
Single Family ◽  
Loss Analysis ◽  
Increase Energy Efficiency ◽  
Electricity Cost ◽  
Air Infiltration ◽  
Detached House

This paper represents an energy consumption and heat loss analysis of a heat recovery ventilator unit in a single-family detached house in St. John’s, NL, Canada. An energy-efficient house is a growing attraction to control the air infiltration, provide a comfortable environment with reduced yearly electricity cost. A mechanical induced ventilation system is inevitable to increase energy efficiency and to reduce greenhouse gas emissions of the house in order to supply fresh air. A heat recovery ventilator (HRV) is an air to air heat exchangers that recovers heat from inside of the house and delivers this preheated and fresh air to the space for maintaining the occupant’s comfort. In this paper, yearly energy consumption with the heat loss of a typical heat recovery ventilator unit is presented. MATLAB, BE opt, and Microsoft Excel are used to do all necessary simulation with calculation using one-year logged data. Methodology, results with graphs and detailed analysis of this research are included in this paper. This research indicates that the cost of running a HRV for a year in a house in St. John’s could be as high as $484 per year with an unknown air quality improvement.

scholarly journals Simulation of a convective loop for the NTED™ low energy house

2021 ◽  
Author(s):  
Ian Stahlbrand
Keyword(s):  
Heat Loss ◽  
Heat Pump ◽  
Software Package ◽  
Heat Recovery ◽  
Buffer Zone ◽  
Low Energy ◽  
Temperature Stratification ◽  
The Core ◽  
Living Space ◽  
House Design

The Nested Thermal Envelope Design (NTED™) is an innovative low energy house design that incorporates two thermal envelopes to create a core and perimeter zone. The perimeter acts as a thermal buffer zone, where heat loss from the core and solar gain in the perimeter is recovered to the core via an inter-zone heat pump. In order to optimize heat recovery from the perimeter and minimize temperature stratification, a complete loop is formed around the core living space, through which air may flow in a convective loop. A simplified convective loop was modelled with a commercial CFD software package. Simulations show the convective loop distributes solar gains and reduces temperature stratification in the perimeter. The location of the heat pump in the convective loop was found to affect the DOP by up to 21%.

scholarly journals Heat recovery by means of a ventilation unit

2021 ◽  
Vol 263 ◽  
pp. 04025
Author(s):  
Dmitrii Khlopitsyn ◽  
Andrey Rymarov
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Heat Recovery ◽  
New Technologies ◽  
Ventilation System ◽  
New Developments ◽  
Before And After ◽  
Save Energy ◽  
Recuperative Heat Exchanger ◽  
Air Removal

Energy consumption all over the world is constantly growing. To save energy, new technologies are being developed for the efficient use of energy resources. The goal of all new developments is to use less energy to provide the same level of energy supply for technological processes or buildings. The problem of energy saving is relevant for the ventilation system. Together with the removed air, a large amount of heat is lost, which is not advisable. In order to avoid these losses, heat recuperators began to be used, heating the cold supply air due to the warm air removed from the room. This development belongs to the field of energy saving. The goal is to increase efficiency by reheating the air after the heater with the help of a recuperator for a given temperature difference in the supply air before and after the recuperative heat exchanger. The development is a design of a ventilation unit with air removal and supply air ducts, combined into one housing with a separate, according to the “screw” principle, heat transfer wall, for use in the ventilation system in order to ensure an optimal microclimate in the room. Thus, as a result of using the presented device, the efficiency of the room ventilation unit is increased by reducing the energy consumption for heating the supply air with a heater.

Biodiesel Fueled Engine Generator With Heat Recovery

2008 ◽  
Author(s):  
Fred Betz ◽  
Chris Damm ◽  
David Archer ◽  
Brian Goodwin
Keyword(s):  
Heat Recovery ◽  
Mechanical Engineering ◽  
Thermal Power ◽  
Ventilation System ◽  
Performance Testing ◽  
Electric Utility ◽  
Hot Water ◽  
Space Heating ◽  
Automation System ◽  
Absorption Chiller

Carnegie Mellon University’s departments of Architecture and Mechanical Engineering have teamed with Milwaukee School of Engineering’s Mechanical Engineering department to design and install a biodiesel fueled engine-generator with heat recovery equipment to supply electric and thermal power to an office building on campus, the Intelligent Workplace (IW). The installation was completed in early September 2007, and is currently being commissioned. Full scale testing will begin in early 2008. The turbocharged diesel engine-generator set is operated in parallel with the local electric utility and the campus steam grid. The system is capable of generating 25 kW of electric power while providing 18 kW of thermal power in the form of steam from an exhaust gas boiler. The steam is delivered to a double-effect Li-Br absorption chiller, which supplies chilled water to the IW for space cooling in the summer or hot water for space heating in the winter. Furthermore, the steam can be delivered to the campus steam grid during the fall and spring when neither heating nor cooling is required in the IW. Additionally, thermal energy will be recovered from the coolant to provide hot water for space heating in the winter, and for regenerating a solid desiccant dehumidification ventilation system in summer. All relevant temperatures, pressures, and flows for these systems are monitored via a building automation system. Pressure versus time measurements can be recorded in each cylinder of the engine. Emissions of nitric oxide (NO), nitrous oxide (NO2), Particulate Matter (PM), and carbon dioxide (CO2) are also monitored. Upon completion of this installation and the system performance testing, the operation of the engine generator with its heat recovery components will be integrated with the other HVAC components of the IW including a parabolic trough solar thermal driven LiBr absorption chiller, a solid desiccant dehumidification ventilation system, and multiple types of fan coils and radiant heating and cooling devices. This energy supply system is expected to reduce the IW’s primary energy consumption by half in addition to the 75% energy savings already realized as compared to the average US office space.

Determining the impact of air-side cleaning for heat exchangers in ventilation systems

2019 ◽  
Vol 41 (1) ◽  
pp. 46-59 ◽  
Author(s):  
Akram Abdul Hamid ◽  
Dennis Johansson ◽  
Michael Lempart
Keyword(s):  
Pressure Drop ◽  
Energy Loss ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Energy Use ◽  
Ventilation System ◽  
Field Measurements ◽  
The Impact ◽  
Over Time ◽  
Ventilation Systems

Cleaning coils can be an efficient way to reduce the need for reparations and maintain the functionality of a ventilation system. This study builds upon existing knowledge concerning the contamination of heat exchangers. Through field measurements on coils and heat-recovery units, a laboratory experiment on a coil, and a generic calculation example, this study determines the impact of sustained contamination on heat-recovery units with regards to energy use. Field measurements made before and after cleaning of heat exchangers show an average increase in the pressure drop by 12% and decrease in the thermal exchange efficiency by 8.1% due to mass deposited on the surface of the heat exchangers. Results from a laboratory test show a correlation between the mass deposited on a coil and (1) the increase in pressure drop over the coil, as well as (2) a diminishing heat exchange. Accumulating contamination on heat-recovery units in residential and commercial buildings (over time) is then linked to increasing pressure drop and diminishing thermal efficiency. With models based on these links, energy loss over time is calculated based on a generic calculation example in a realistic scenario. Practical application: The results from this study emphasize the need for maintenance of buildings with ventilation systems with coils, but more so those with heat-recovery units. The presented field measurements and laboratory study correlate energy loss with sustained accumulation of contaminants on coils and heat-recovery units. These results should serve as a recommendation to property owners considering maintenance of such units in their buildings.

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