Sky bridge roof surface

Cooling Tokyo Haneda with Radi-Cool™ Film

Renowned for its efficiency and passenger satisfaction, Tokyo Haneda Airport consistently ranks as one of the world’s best airports. With a commitment to sustainability and environmental initiatives, Haneda installed Radi-Cool™ to reduce air conditioning demand and increase passenger comfort.

In a 2020 pilot project, Radi-Cool™ reflective film was installed on the 3,230 ft² roof of sky bridge #4 that connects the airport terminal to parking garage #4. Sky bridge #3 was maintained as a control to measure cooling performance. Test measurements and thermal images captured on 4 July, 2020 at 11:00 AM are discussed below.

Conditions

Results

Roof Surface Temp

Radi-Cool™

0

°F

Control

0

°F

Cooling

0

°F

Interior Ceiling Temp

Radi-Cool™

0

°F

Control

0

°F

Cooling

0

°F

Discussion

Radi-Cool™ provided significant zero-energy cooling of both the roof surface and interior space of the experimental sky bridge. With the completion of this successful pilot project, airport management moved ahead with large-scale installation of Radi-Cool™ reflective and transparent cooling films.

Passive daytime radiative cooling is particularly beneficial for airports due to their large asphalt tarmacs and sprawling passenger terminals. PDRC significantly reduces air conditioning demand, which represents a large energy sink for most airports. Additionally, lower ambient temperatures contribute to enhanced comfort for passengers and airport personnel, making the overall airport environment more pleasant. Because of this, Radi-Cool™ has found itself at home installed at these other notable international airports:

  • Changi International Airport, Singapore (passenger loading bridge energy savings average 44% over two year PLB study)
  • Hangzhou Xiaoshan International Airport, China (maximum 39°F drop in ceiling temperature)
  • Ningbo International Airport, China (maximum 12.6°F drop in interior air temperature)

Summer Savings with Radi-Cool™ Film

Two identical modular structures were assembled on a Foxconn rooftop in Shenzhen, China. One structure’s roof and walls were coated with Radi-Cool™ reflective film, while the other kept uncoated aluminum panels. Both structures had identical mini-split air conditioners set to maintain 70°F (21°C).


Energy use was measured for both structures between June 14th and June 16th, 2019. Recorded highs were 90°F, 91°F, and 90°F for the three days, respectively. Recorded lows were 79°F, 77°F, 79°F, respectively.

Results

  • 3-day energy use reduced to 5.6 kWh from 14.4 kWh
  • Peak hourly energy use reduced to 0.22 kWh from 0.58 kWh

Energy Savings (kWh)

61%

Peak Energy Use (kWH)

38%

Discussion

The modular building test is a near best case scenario for PDRC cooling, with a non-shaded and semi-insulated structure subject to both high ambient day and night temperatures and intense summer solar radiation. Radi-Cool™ reflective film is well-suited for traditionally difficult cooling tasks, especially where insulation and shading are prohibited by cost, size, weight, or other engineering restrictions. In addition, significant reductions in both average and peak electricity use makes Radi-Cool™ perfect for off-grid cooling.

Modular Structure

Electricity Used (kWh)

Control

Radi-Cool™

↓ 61.9%
June 14
↓ 62.7%
June 15
↓ 58.6%
June 16

Experimental granary satellite view
Laying Radi-Cool Membrane on Granary #26
Granary #26 completed

Zhejiang Granary

Indoor Air Temp (°F)

Control

Radi-Cool™

Zhejiang Granary

Grain Temp (°F)

Control

Radi-Cool™

Improving Quality & Cost with Radi-Cool™ Membrane

The goal of any granary is to maintain optimal storage conditions (<77°F) with minimum electricity and cost. A large-scale PDRC granary test was conducted in Zhejiang, China at the Zhejiang Provincial Grain Storage facility. Radi-Cool™ reflective membrane was installed on the roof of Granary #26. Granary #25, located directly adjacent to the experimental granary, was maintained as a control with its existing PVC membraned, concrete roof. The granaries each have a roof area of 13,500 ft² and store ~3,700 tons of wheat.

Results

With air conditioning off:

  • Maximum roof temperature reduced by 48.8°F (27.1°C)
  • Maximum sub-roof interlayer temperature reduced by 37°F (20.5°C)
  • Maximum interior temperature reduced by 18.3°F (10.2°C) on 6/08/2021
  • Maximum grain temperature reduced by 8.1°F (4.5°C) on 8/13/2021
  • Both roof and sub-roof interlayer remained sub-ambient 24/7
  • Maximum cooling occurred in late summer, as required
  • Winter overcooling minimized, as expected


With air conditioning on:

  • Energy use reduced by 33.4 – 43.3%
  • Average energy use reduced by 39.5%
Avg Indoor Air Temp

Radi-Cool™

0

°F

Control

0

°F

Cooling

0

°F

Avg Indoor Air Temp (Summer)

Radi-Cool™

0

°F

Control

0

°F

Cooling

0

°F

Avg Indoor Air Temp (Winter)

Radi-Cool™

0

°F

Control

0

°F

Cooling

0

°F

Max Indoor Air Temp

Radi-Cool™

0

°F

Control

0

°F

Cooling

0

°F

% Time Air Below 77°F

Radi-Cool™

70%

Control

55%
Avg Grain Temp

Radi-Cool™

0

°F

Control

0

°F

Cooling

0

°F

Max Grain Temp

Radi-Cool™

0

°F

Control

0

°F

Cooling

0

°F