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

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

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

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)

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!!!

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

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

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

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)

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%

Step 2Estimation of CRCP Capacity

Step 2Estimation of CRCP Capacity

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

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

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)

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

Integrated Fire Suppression SystemIntegrated Fire Suppression System

CHECKCHECKVALVEVALVECHECKCHECKVALVEVALVE

ALARMALARMVALVEVALVEALARMALARMVALVEVALVE

FIREFIREFLOWFLOW

SWITCHSWITCH

FIREFIREFLOWFLOW

SWITCHSWITCH

FIREFIREPUMPPUMP

ASSEMBLYASSEMBLY

FIREFIREPUMPPUMP

ASSEMBLYASSEMBLY

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

QuestionsQuestions