School of Civil Engineering

Integrating Heat Transfer Devices Into Wind Tower Systems to provide Thermal Comfort in Residential Buildings

John Kaiser S. CalautitSupervisors: Dr. B. Hughes and Prof. N. Wright3rd CFD Group Meeting

School of Civil Engineering

John Kaiser S. Calautit

Wind Tower – Natural Ventilation Device

Stale Air Out

Fresh Air In

(Micro Climate)

- Leeward

+ Windward

(Macro Climate)((

(Macro Climate)((

• • Originated from the Middle East (hot and arid regions).

• Incorporated with advance technology (control dampers, ceiling diffusers , solar panels)

Traditional Architecture Commercialized Re-Engineering

• Bring the technology back to the Middle East using heat transfer devices powered system.

Buoyancy and displacement effect (driving forces)

Windward (+) Leeward (-)

School of Civil Engineering

Looking into Wind Tower Systems – Airflow Analysis

• Supplies airflow at ceiling level

• Increased the indoor airflow by up to 60%

• Two 4-sided wind tower system (2 floor residential building)

• Average indoor airflow of 0.4 m/s

John Kaiser S. Calautit

School of Civil Engineering

Traditional Evaporative Cooling (Controlled Test): Existing Cooling Technology

0 1 2 3 4 5 6 7 8 9 10293295297299301303305307309311 Evaporative cooling

Position (m)

Stat

ic T

empe

ratu

re (k

)

Disadvantages:

1. Water - scarce

2. Pump – continuous power supply

3. High Tower – not feasible in urban areas

297 K

Wind Tower Channel with Evaporative Cooling (Published Data)

310K

297 K

John Kaiser S. Calautit

Inlet310K

Outlet

Injected Water 0.05 kg/s, 293K

School of Civil Engineering

John Kaiser S. Calautit

Top Hat

Adjustable Dampers

Louver

1. Integrate heat transfer devices into a commercial wind tower system for the Middle East.

Aims and Objective:

Evaporator

Condenser

Heat exchanger system

School of Civil Engineering

John Kaiser S. Calautit

2. Optimize the thermal comfort of a Qatari residence using the proposed wind tower system. Predicting thermal comfort using PMV model software.

0 5 10 15 20 2505

1015202530354045

Summer - June

InsideOutside

Time (Hour)

Tem

per

atu

re (

C°)

35 C°

Predict Thermal Comfort

•Required Indoor Temperature?•Required Indoor Velocity?

Hottest Month

School of Civil Engineering

John Kaiser S. Calautit

Challenges:

1. Reduce the indoor temperature by 10-12K to achieve thermal comfort during summer periods.

2. Achieve minimal restriction in the external air flow stream while ensuring maximum contact time. Supply up to 400 L/s

3. Compact Design - Fit the heat transfer devices and cool sink inside wind tower.

4. Cool Sink

5. Dust

School of Civil Engineering

John Kaiser S. Calautit

CFD Results : Airflow Analysis – Louver Angle (Components)

2.55 m/s

3.31m/s

45˚ 35˚

Reduced Air CirculationHigh Air Circulation

1 m/s 1 m/sUnavoidable due to the louvers and 90˚ bend

School of Civil Engineering

John Kaiser S. Calautit

Research Output: Publications

• B R Hughes, J K Calautit, S A Ghani, The development of commercial wind towers for natural ventilation: A review, Applied Energy, 92, 606-627, 2012

• J K Calautit, B R Hughes, S A Ghani, A Numerical Investigation into the Feasibility of Integrating Green Building Technologies into Row Houses in the Middle East, Architectural Science Review, 55, 1-18, 2012.

Future Work:

• CFD (Transient Modeling, UDF, Solar Loading, Dynamic Mesh)

• Experimental Work (Wind Tunnel Design, Scaled-Model Testing)

• Qatar Visit (Duct Testing and Full Scale Testing)