Ceiling%20Radiant%20Cooling%20Panels%20as%20a%20Viable%20Distributed%20Parallel%20Sensible%20Cooling%20Technology

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Ceiling Radiant Cooling Panels as a Viable
Distributed Parallel Sensible Cooling Technology
Integrated with Dedicated Outdoor Air Systems

• Christopher L. Conroy, E.I.T.
• L. D. Astorino Companies, Pittsburgh PA
• Stanley A. Mumma, Ph.D., P.E.
• Penn State University, Dept. of Architectural
  Engineering

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Presentation Overview

• Introduction
• Radiant Cooling Theory
• HVAC Paradigm
• Advantages
• Example
• Integration of Fire Suppression
• Conclusions and Solutions

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Integrating Dedicated Outdoor Air Systems with
Parallel Terminal Systems
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Radiant Cooling Theory

• Uses both Radiation and Convection
• Radiation (50-60)
• Stefan-Boltzmann Equation
• qr 0.15x10-8 (tp460)4 (ta460)4
• Convection (40-50)
• ASHRAE SE 1996
• qc 0.31 tp- ta0.31 (tp- ta)

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Radiant Cooling Paradigm

• Expensive
• High first cost
• Difficult or improper installation
• Unavailable

• Condensation!!!
• Condensation!!!
• Condensation!!!

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Radiant Cooling Panel Construction
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Cost Advantages

• Long Term Savings
• Smaller, More Efficient Chillers
• Reduced Fan Energy
• Reduced Maintenance Cost
• Not paying for Over Ventilating
• Other Cost Savings
• Piping is not insulated
• Reduced Sprinkler Piping
• Testing and Balancing Made Simpler

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Indoor Air Quality Advantages

• High comfort levels
• No condensate drains or drain pans
• Meets ANSI/ASHRAE Std 62-1999
• Quick response time
• Individual room control at low cost

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Building Advantages

• Architecturally Integratable
• Silk screening available
• Perforated face (acoustics)
• Great for Retrofit or New Construction
• Reduces Mechanical Space
• Less Ductwork
• Less vertical shaft space
• Higher ceilings and/or reduced building heights
• Simpler Coordination Between Trades
• Integration of fire suppression
• Less interferences (crossover ductwork)

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Example Step 1Defining Parameters

• Open Office Plan
• 1000 ft2
• Define Design Conditions
• 78ºF DBT / 40 RH
• 7 People (20 cfm/person)
• Space Loads
• 7 People (Office Work)
• 2 W/sq ft (Lighting)
• 1 W/sq ft (Equipment)
• 4,000 Btu/h (Skin Loss)

• 14,000 Btu/h (Total Sensible)
• 1,435 Btu/h (Total Latent)

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Step 2Estimation of CRCP Capacity
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Step 3Calculation of CRCP Capacity

• Room DPT 52F
• 78F / 40 RH
• DOAS DPT 44F
• 1,435 Btuh Latent Load
• 140 cfm _at_ 55F
• 3,500 Btuh Sensible Load

• Panel tfi 55F
• Panel Temp 60F
• Qs 29.7 Btuh/ft2
• 10,500 Btuh
• 354 ft2 of panel

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Step 4Selection and Layout of CRCP

• 126 4x2 Ceiling Panels
• 1000 ft2
• 24 Light Fixtures
• 20 of Ceiling
• 49 Ceiling Radiant Cooling Panels
• 392 ft2 (40)
• 400 sq. ft. Leftover
• Diffusers
• Sprinklers
• Qs 26.7 Btuh/ft2
• Room RH 43
• Increase DOAS DPT

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Step 5Compare Acoustical Performance of CRCP
Acoustical Ceiling Vs CRCP
Reverberation Time (sec)
Frequency (Hz)
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Chilled Water Loop
COMPRESSION TANK
MAKE-UP PUMP
ZONE VALVES
CRCPs
SECONDARY PUMP (VFD)
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Integrated Fire Suppression System
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Conclusions and Solutions

• Seen the Advantages
• Concluded that CRCPs can be Used Safely with No
  Condensation Problems
• Defined a Simple Selection Process
• Examined the Opportunity for Fire Suppression
  Integration

• Break the HVAC Paradigm
• More Successful Applications
• Spreading the Word
• Explore the Possibilities of Lowering Cost
• Increase Availability
• Research a way to produce custom lengths on site
• Development Through the Solar Industry

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Questions