Summary of Contents for Holocene Technologies HotoTech
- Page 1 HoloTech Solar Hot Water System Installation Manual Ben Gravely, PhD Holocene Technologies 1241 Wicker Drive Raleigh, NC 27604 (c) 2012...
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Page 2: Table Of Contents
HoloTech Solar Installation Manual Table of Contents 1. Planning the Installation 1.1 Site Analysis 1.2 Collector Tilt 1.3 Materials 2. Tank Installation 3. Collector Installation and Controls 3.1 Frame and Collector Mounting 3.2 Collector Piping 3.3 Pipe Insulation 3.4 Solar Controls and Wiring 3.5 Collector System Startup 4. -
Page 3: Planning The Installation
This manual was written to provide straight forward procedures for the installation of HoloTech solar hot water systems manufactured by Holocene Technologies. As with any project, a few minutes of planning will save hours of fixing. The installer is responsible for knowing local regulatory codes and how they apply to the equipment. If in doubt, a visit with local code officials can prevent on-site inspection problems. -
Page 4: Materials
HoloTech Solar Installation Manual 1.3 Materials In addition to standard tools and plumbing parts, make sure to include hole saws, silicone sealant, and roof flashing boots. Collector piping should be 3/4" or greater for proper draining. Use only metal piping in the collector loop. Space heating and DHW circuits can use any code approved piping. - Page 5 HoloTech Solar Installation Manual It is very important to leak test and flush the collector lines before final connection to the tank. The tank is easily filled and maintained with the boiler drain valve at the bottom of NOTE Do not apply power to the controls until all plumbing and wiring is complete and the tank has been filled with water.
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Page 6: Frame And Collector Mounting
HoloTech Solar Installation Manual 3. Collectors 3.1 Frame and Collector Mounting Typical flat plate collector mounting hardware is shown in fig. 3.1. Different collector brands have different hardware, but the essentials are the same. There are three angles that must be considered when installing an array of solar collectors. - Page 7 HoloTech Solar Installation Manual there is insufficient drain slope, water standing in the supply header can freeze in the winter and burst the pipe. If the drain slope is too much, water can be trapped in the stub end of the return header and cause freezing problems in the winter. The drain slope should be 1 inch in 20 feet (approximately 1/4°...
- Page 8 HoloTech Solar Installation Manual After laying out the sloped chalk line, mark the position of the feet along the line. Drill a 1/4" pilot hole through the roof to locate the position of the purlin underneath. Secure the purlin underneath, then redrill through the hole for a 3/8 in. bolt. Figure 3.5 shows different options for the roof mounting structure.
- Page 9 HoloTech Solar Installation Manual Hi Sensor Location Drain Slope Line Horizontal Line Return Supply Sensor Location Figure 3.2 Collector Piping Circuit Figure 3.6. Collector to tank piping layout.
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Page 10: Collector Piping
HoloTech Solar Installation Manual 3.2 Collector Piping The recommended flow rate for each collector is 0.025+/-.005 GPM/ft2. Consult the chart below to determine the proper pipe size for different collector areas. Use only metal pipe in the collector loop. Either type L or M copper is satisfactory, since the piping is operated only at atmospheric pressure. - Page 11 HoloTech Solar Installation Manual Figure 3.8 shows piping routines for different numbers of collectors placed on a sloped roof. Because excessive expansion and contraction of the headers with temperature swings can cause failure in the piping, it is recommended that no more than five four foot wide collectors be joined together in one bank as shown in fig.
- Page 12 HoloTech Solar Installation Manual Drain Slope Figure 3.3 Collector Piping Diagrams Figure 3.8 Collector piping for arrays in the same plane.
- Page 13 HoloTech Solar Installation Manual Return Supply Flow Setter Valves Return Supply Figure 3.4 Dual Bank Piping Diagrams Figure 3.9 Collector piping for arrays on a flat roof.
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Page 14: Pipe Insulation
HoloTech Solar Installation Manual Avoid running square corners in unfinished areas, go straight across. Most traps are created by using many elbows and right angle turns. Soft copper may be used in situations requiring many turns. Be careful that soft copper doesn't sag and cause traps. -
Page 15: Solar Controls And Wiring
HoloTech Solar Installation Manual 3.4 Solar Controls and Wiring Differential controllers (called "Delta-T" controllers) are used to operate the collectors, recirculator DHW option, and pools/spas. The temperature sensors are wired with two- conductor 18-24 ga. bell wire. If the length of the wire is over 50 ft. use 18 ga. Be careful when running sensor hook-up wire through the building to avoid shorting or breaking the wires with staples, or scraping the insulation off on sharp metal edges. - Page 16 HoloTech Solar Installation Manual surrounding temperature. Errors in temperature readings can cause improper operation of the controller and poor performance of the equipment. The low/OVT sensor for the collector circuit is installed on the solar tank at the factory. Mount the high sensor on the return header of the last collector in the array as shown in fig.
- Page 17 HoloTech Solar Installation Manual 3.5 System Startup The startup of the solar system is done only after everything is completely installed and the tank filled with water. The electrical power may then be connected. Caution Do not operate a controller until all plumbing has been completed and the tank is full of water.
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Page 18: Domestic Hot Water
HoloTech Solar Installation Manual 4. Domestic Hot water 4.1 Single Pass Piping There are several options for hooking up domestic hot water circuits. The standard option, shown in fig. 4.1 is called a "single pass" system. The cold water line goes through the solar heat exchanger and then to the inlet on the standard water heater. -
Page 19: Dhw System Startup
HoloTech Solar Installation Manual The added expense of a recirc system is not usually warranted unless the solar tank and the conventional water heater are far apart. 4.3 DHW System Startup Controller Cold Water Hi Temp Heater Sensor Cut Dip Tube Lo Temp Sensor... -
Page 20: Collector System
HoloTech Solar Installation Manual Automatic operation of the controller can be determined only if the solar tank is 15°F warmer than the bottom of the standard water heater. For a cold system test, refer to the trouble shooting section in the Appendix for testing Delta-T controllers. Appendix 1. -
Page 21: Differential (Delta-T) Controllers
HoloTech Solar Installation Manual A1.2 Differential (delta-T) Controllers Differential controllers, or delta-T controllers, are used in the collector, pool/spa, DHW recirculator, and boiler options. They all have a high temperature sensor, and a low temperature sensor. The over temperature (OVT) or high limit function comes from the low sensor on the tank. - Page 22 HoloTech Solar Installation Manual Table A1.2 Sensor Temperature vs Resistance HoloTech solar controls use 10K thermistor temperature sensors. These devices change resistance with temperature. They are defined by having 10KΩ resistance at 25ºC (77ºF).
- Page 23 HoloTech Solar Installation Manual A1.3 Pumps TACO brand pumps are used extensively on HoloTech systems. On the smaller pumps, the bodies can be disassembled and the rotor cartridge replaced without removing the pump from the line. For detailed drawings of the components, check the pump literature. Replacement parts are available from Holocene.
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Page 24: About The Author
HoloTech Solar Installation Manual About the Author In 1977, Dr. Ben Gravely established Gravely Research Corporation (GRC) to pursue various optical and thermal inventions for solar energy systems, for which two patents were granted. Other inventions include a range of thermal energy products including thermal storage systems, heat exchangers, a thermal engine, and a high sensitivity, low cost, flow sensing device.
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