Radiant Cooling: System design

Objective:

To design a radiant cooling system analytically considering a live room/space within the college campus.

Outcome:

Students will learn about sustainable cooling systems and technologies which can help reduce the use of Air Conditioners. 

Requirements:

Pre selected room and documented with basic space and temperature measurements, Thermo-hygrometer, A mentor/teacher to help conduct the calculations for the system

Prerequisites:

Fundamental knowledge of radiant cooling system and heat transfer principles 

Procedure:

Step 1: Ask students to identify a room or a space in the college campus itself which can be considered for the radiant cooling system design. Take the space measurements, temperature as detailed below in the design process steps. The teacher will be guiding the students in conducting this calculation based exercise. Since there are 5 steps, the teacher can form 5 groups out of the class and each group will do one calculation each in an order as stated below:

1. Building/Zone Heat Load calculation: This step primarily involves the floor area, dry bulb temperature (sensible load) inside the room, wet bulb temperature (latent heat) inside the room, outside temperature, relative and absolute humidity.
2. Heat Transfer calculation: This step primarily involves understanding the heat absorption and conductivity of the materials that are used in the room. It also includes thermal conductivity of the materials used for radiant cooling such as pipes, water temperature, spacing and cover of the layers, etc.
3. System sizing and performance: This step primarily involves calculation of the specific cooling capacity/output needed for the area considering the temperature differences of surfaces and the air (Q (Watts) = Ux∆T) and the heat transfer area (floor, wall, slab or ceiling panel)required. 
4. Hydraulic Design: This step involves calculating the specific details of loop (pipe) i.e. length, area, spacing in between the pipes, water pressure, flow rate and output direction.
5. Ventilation and Dehumidification System design: This step involves the system layout positioning the Air Handling unit, ducts and dehumidification equipment (VCR/VAM).

Step 2: Ideally if the selected room can be given for live radiant cooling system installation post design, it would be the most effective. Experience the cooling and temperature inside the room. 

Step 3: Monitor and assess the differences in room air temperature, experienced temperature and reduced energy (electricity) consumption. Calculate the initial installation cost (cost per sq meter) and energy savings, and compare it with the Airconditioning energy consumption. 

References:

http://fairconditioning.org/

Fairconditioning youtube channel: Radiant Cooling Animation

Radiant cooling presentation