DESIGN: SOLAR HEATING OF BUILDINGS AND DOMESTIC HOT

1,54

MB

WATER

167

stron

5030

ID

UNITED STATES ARMY CORPS OF ENGINEERS

2004

rok

CONTENTS

1.0 INTRODUCTION . 1

1.1 Scope 1

1.2 Related Criteria . 1

1.3 Solar Energy . 4

1.3.1 Solar Radiation . 4

1.3.2 Collecting Solar Energy . 4

1.3.3 Solar Collector Orientation . 12

1.3.4 Advantages and Disadvantages 14

2.0 SOLAR SYSTEM COMPONENTS 15

2.1 Collectors . 15

2.1.1 Liquid and Air-Type Collectors 17

2.1.2 Selective Surfaces 17

2.1.3 Collector Covers (Glazes) . 19

2.1.4 Collector Insulation 22

2.1.5 Collector Housings 22

2.1.6 Collector Gaskets and Sealants 24

2.1.7 Collector Fluids - Corrosion and Freeze Protection 25

2.1.7.1 Silicone Fluids 30

2.1.7.2 Hydrocarbons . 33

2.1.7.3 Distilled Water 33

2.1.7.4 Water/Antifreeze . 33

2.1.8 Collector Connections . 34

2.1.9 Collector Efficiency and Heat Losses 36

2.1.10 Other Types of Solar Collectors 46

2.1.10.1 Evacuated-Tube Collectors . 46

2.1.10.2 Concentrating Collectors 47

2.2 Energy Storage and Auxiliary Heat 48

2.2.1 Storage Tanks . 51

2.3 Domestic Hot Water Systems (DHW) . 52

2.4 Thermosyphon, Batch, and Integral Storage Collector Systems 57

2.5 Space Heating and DHW Systems 58

2.5.1 Heat Distribution for Liquid-Type Solar Systems . 62

2.5.2 Heat Distribution for Air-Type Solar Systems 63

2.5.3 Heat Pumps 64

2.6 Passive Systems 68

2.7 Solar Cooling Systems 74

2.7.1 Absorption Cooling 74

2.7.2 Bankine Cycle Heat Engine Cooling . 76

2.7.3 Desiccant Cooling . 77

2.7.4 Other Cooling Methods . 79

2.7.5 Estimating System Size 79

2.8 System Controls 80

2.9 Piping, Pumps, Valves 82

2.9.1 Pipe and Header Sizing 82

2.9.2 Pumps and Collector Flowrate 83

2.9.3 Valves 83

2.10 Other Considerations 84

2.10.1 Architectural 84

2.10.2 Reduction of Heat Losses 84

2.10.3 Maintenance and Accessibility 84

2.10.4 Contract Submittals Required . 85

3.0 DESIGN METHODS . 87

3.1 Job Summary - Worksheet A 87

3.2 Solar Collector Parameters - Worksheet B . 87

3.3 Load Calculations - Worksheet C-1 90

3.4 Demand Calculations - DHW - Worksheet C-2 91

3.5 Monthly Solar Collection Parameters - Worksheet D-1 98

3.6 Fraction of Load Supplied by Solar Heat - Worksheet D-2 98

3.7 Economic Analysis 107

3.7.1 Fuel Savings - Worksheet E-1 107

3.7.2 Operating and Maintenance (O&M) Costs . 109

3.7.3 Present Worth Analysis and Savings Investment Ratio . 109

3.7.3.1 Present Worth Analysis Using a Discount Factor - Worksheet E-1 or E-2 110

3.7.3.2 Present Worth Analysis Without the Discount Factor - Worksheet E-1 111

3.8 Collector Temperatures - Worksheet E-1 . 111

3.9 Solar System Cost - Worksheet F 115

3.10 Additional Costs - Worksheet G 115

3.11 Sizing the Heat Exchanges for Space Heating . 115

3.12 Air-Heating Collector Design - Worksheet H 117

3.13 Worksheets 117

Worksheet A - Job Summary . 119

Worksheet B - Solar Collector Parameters 120

Worksheet C-1 - Load Calculations . 121

Worksheet C-2 - Demand Calculations - Domestic Water Heater . 122

Worksheet D-1 - Monthly Solar Collector Parameters 123

Worksheet D-2 - Fraction of Load Supplied by Solar Heat . 124

Worksheet E-1 - Value of Fuel Saved . 125

Worksheet E-2 - Present Worth Analysis 126

Worksheet F - Solar System Cost Analysis 127

Worksheet G - Additional Cost Items Related to Use of Solar Heating . 128

Worksheet H - Solar Air Collector System Design Summary . 129

4.0 EXAMPLE PROBLEMS . 130

4.1 Discussion of Example 1, Space Heating and DHW System . 130

4.1.1 Example 1 - Worksheets 132

5.0 DIRECTORY OF SOLAR EQUIPMENT MANUFACTURERS . 142

5.1 Manufacturers Directories 142

5.2 Manufacturers of Flat Plate Collectors and Other Solar Hot Water Equipment 142

6.0 REFERENCES (*) AND SELECT BIBLIOGRAPHY . 143

7.0 LIST OF SYMBOLS 150