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Ceiling Radiant Cooling Panels as a Viable Distributed Parallel Sensible Cooling Technology
Ceiling Radiant Cooling Panels as a Viable Distributed Parallel Sensible Cooling Technology
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
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
Integrated with Dedicated Outdoor Air SystemsIntegrated with Dedicated Outdoor Air Systems
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Presentation OverviewPresentation Overview
• Introduction
• Radiant Cooling Theory
• HVAC Paradigm
• Advantages
• Example
• Integration of Fire Suppression
• Conclusions and Solutions
• Introduction
• Radiant Cooling Theory
• HVAC Paradigm
• Advantages
• Example
• Integration of Fire Suppression
• Conclusions and Solutions
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Integrating Dedicated Outdoor Air Systems withIntegrating Dedicated Outdoor Air Systems with
Parallel Terminal SystemsParallel Terminal Systems
Radiant Cooling PanelsRadiant Cooling Panels
Fan Coil UnitsFan Coil Units
Air Handling UnitsAir Handling Units
Unitary ACsUnitary ACs
Unit VentilatorsUnit Ventilators
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Radiant Cooling TheoryRadiant Cooling Theory
• Uses both Radiation and Convection
• Radiation (50-60%)» Stefan-Boltzmann Equation» qr = 0.15x10-8 · [(tp+460)4 – (ta+460)4]
• Convection (40-50%)» ASHRAE S&E 1996
» qc = 0.31 · |tp- ta|0.31 · (tp- ta)
• Uses both Radiation and Convection
• Radiation (50-60%)» Stefan-Boltzmann Equation» qr = 0.15x10-8 · [(tp+460)4 – (ta+460)4]
• Convection (40-50%)» ASHRAE S&E 1996
» qc = 0.31 · |tp- ta|0.31 · (tp- ta)
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Radiant Cooling ParadigmRadiant Cooling Paradigm
• Expensive» High first cost» Difficult or improper
installation» Unavailable
• Expensive» High first cost» Difficult or improper
installation» Unavailable
• Condensation!!!• Condensation!!!• Condensation!!!
• Condensation!!!• Condensation!!!• Condensation!!!
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Radiant Cooling Panel ConstructionRadiant Cooling Panel Construction
Copper Tubing
(Serpentine or Parallel
Arrangement)
Copper Tubing
(Serpentine or Parallel
Arrangement)
Aluminum or Copper Fins
Aluminum or Copper Fins
Thermally Bonded
Thermally Bonded
Blanketed with Insulation
Blanketed with Insulation
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Cost AdvantagesCost 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
• 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 AdvantagesIndoor 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
• 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 AdvantagesBuilding 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)
• 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
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)
• 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)» 14,000 Btu/h (Total Sensible)» 1,435 Btu/h (Total Latent)
1000 ft1000 ft221000 ft1000 ft22
7878°F / 40%°F / 40%7878°F / 40%°F / 40%
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Step 2Estimation of CRCP Capacity
Step 2Estimation of CRCP Capacity
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Step 3Calculation of CRCP Capacity
Step 3Calculation of CRCP Capacity
• Room DPT = 52°F» 78°F / 40% RH
• DOAS DPT = 44°F» 1,435 Btuh Latent Load» 140 cfm @ 55°F» 3,500 Btuh Sensible Load
• Room DPT = 52°F» 78°F / 40% RH
• DOAS DPT = 44°F» 1,435 Btuh Latent Load» 140 cfm @ 55°F» 3,500 Btuh Sensible Load
• Panel tfi = 55°F
• Panel Temp = 60°F
• Qs = 29.7 Btuh/ft2
» 10,500 Btuh
» 354 ft2 of panel
• Panel tfi = 55°F
• Panel Temp = 60°F
• Qs = 29.7 Btuh/ft2
» 10,500 Btuh
» 354 ft2 of panel
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Step 4Selection and Layout of CRCP
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
• 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
Step 5Compare Acoustical Performance of CRCP
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
125 250 500 1000 2000 4000
Acoustical Ceiling Vs CRCPAcoustical Ceiling Vs CRCP
Frequency (Hz)Frequency (Hz)
Rev
erbe
rati
on T
ime
(sec
)R
ever
bera
tion
Tim
e (s
ec)
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Chilled Water LoopChilled Water LoopT
ZONEZONEVALVESVALVES
ZONEZONEVALVESVALVES
CRCP’sCRCP’sCRCP’sCRCP’s
SECONDARYSECONDARYPUMPPUMP(VFD)(VFD)
SECONDARYSECONDARYPUMPPUMP(VFD)(VFD)
COMPRESSIONCOMPRESSIONTANKTANK
COMPRESSIONCOMPRESSIONTANKTANK MAKE-UPMAKE-UP
PUMPPUMPMAKE-UPMAKE-UP
PUMPPUMP
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Integrated Fire Suppression SystemIntegrated Fire Suppression System
CHECKCHECKVALVEVALVECHECKCHECKVALVEVALVE
ALARMALARMVALVEVALVEALARMALARMVALVEVALVE
FIREFIREFLOWFLOW
SWITCHSWITCH
FIREFIREFLOWFLOW
SWITCHSWITCH
FIREFIREPUMPPUMP
ASSEMBLYASSEMBLY
FIREFIREPUMPPUMP
ASSEMBLYASSEMBLY
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Conclusions and SolutionsConclusions and Solutions
• Seen the Advantages
• Concluded that CRCP’s can be Used Safely with No Condensation Problems
• Defined a Simple Selection Process
• Examined the Opportunity for Fire Suppression Integration
• Seen the Advantages
• Concluded that CRCP’s 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
• 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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QuestionsQuestions