Fundamentals of Solar Thermal Systems: Engineering Design and Component Choices for Residential and Commercial Systems

A SHW Concentrated Design Char​r​et​t​e for Professionals and Building Owners

This course will be a unique classroom experience where students and the instructors collaborate with hands-on demonstration devices to choose designs and equipment for a custom drain ​back and a pressurized solar thermal systems from the first client contact to the monitoring of the performance of the finished system. This learning exercise will focus on WHY system designs work and fail and WHAT component choices optimize performance, durability and cost effectiveness. What are some of the code and standard of practice elements of the design process.

The charrette will focus on engineering choices that must be made for:

• Load analysis – present and future DHW demand – temperature and volume, time of day, seasonal variation, client vacation & health realities
• CWS quality – long term impacts of water chemistry on performance & components
• Location of the collector array – ground or roof, tilt angles, difficulty of attachment
• System performance simulation tools – the limitations and strengths of math
• Size and type of collectors – flat plate (small or large piping) or tubes (single vs double glass, U tube vs thermal bulb, etc.), seasonal & diurnal performance, maximum hourly output
• Array frame and mounting options and hardware, lightning risk reduction and wind, waterproofing & snow issues, tricks to lift and safely attach equipment
• Lineset materials, routing, hangers, interior diameter insulation & jacketing
• Solar loop choices – drainback or pressurized pipe choices, dynamic & static head loss, flow, pressure and temperature gages, PRVs and piping, drainback tank issues and location,
• Stagnation control – pressure & steam dynamics, HTF chemistry impacts, expansion tank size & piping details, loop pressure choices, hazards during maintenance
• Heat transfer fluids – propylene glycol vs synthetics, pH & buffering, introduction equipment and methods during commissioning
• Solar and DHW pump choices – ECM vs traditional pumps, volute materials, pump curves, multiple pump operation, power consumption, corrosion risks and responses, flanging, heat considerations, drainback vs pressurized pumps
• Solar & backup tank options – atmospheric, pressurized, coil/no coil, water vs PCMs, plastic vs. steel, and how much HTF volume should the tank have
• Heat Exchangers – immersed vs side arm, flat plate vs. coils vs. shell & tube, CSST vs copper vs steel, thermal and head loss performance analysis
• Solar loop pump control – RPM modulation, 0-10 v control, amperage load limits, lightning protection and grounding, spill provisions, PRV provisions
• CWS/DHW balance of system – mixing & anti-scald valves, PEX vs copper, 3 valve bypass, pipe sizing, T&P valves & piping, DHW recirculation challenges, Legionella
• Solar thermal specific components – check valves, valves, sensors, tools
• Space heating considerations – loop design, load analysis, piping & injection options, role of water to water HPs.
• Labeling, insulation, manuals, warrantees, spill and leak provisions
• System performance and failure notification systems – on-site & WWW based
• Client involvement and education for system operation monitoring
• Technical resources and applicable code compendia for design professionals

Dr. Fred Milder is the CEO and co-founder of SolarLogic, a technology company dedicated to simplifying the design, installation, control and monitoring of solar thermal and renewable energy hydronic combisystems. Prior to SolarLogic, Fred founded two medical technology companies. Fred received a B.A. from the Massachusetts Institute of Technology and a Ph.D. in Physics from the University of Michigan. Dr. Milder holds over 30 patents as an inventor.

Primary/Secondary plumbing has many advantages when adapted to combisystem design with renewable heat sources. As examples, solar hydronic systems can benefit from: improved efficiency by bypassing storage whenever possible; combining solar and boiler resources (or not) according to real-time temperatures; prioritization of heating sources and calls for heat; and, providing heat to loads with differing temperature requirements simultaneously. Renewable heat sources other than solar are easily incorporated, as are centralized internet control, monitoring and energy measurements. This session will cover plumbing and performance examples from the field of systems designed using a simple, standardized primary/secondary loop configuration.

Henry K. Vandermark founded Solar Wave Energy Inc. in 1978 and has been involved in all aspects of the design, installation and service of solar thermal systems including site-built and many different types of factory-built collectors and systems used in the northeast. He currently oversees www.thermal-grid.com , a web-based monitoring platform designed to help installers optimize performance of their solar thermal systems. He has taught conference workshops, trade school classes, and programs for teachers.

Dr. Fred Milder is the CEO and co-founder of SolarLogic, a technology company dedicated to simplifying the design, installation, control and monitoring of solar thermal and renewable energy hydronic combisystems. Prior to SolarLogic, Fred founded two medical technology companies. Fred received a B.A. from the Massachusetts Institute of Technology and a Ph.D. in Physics from the University of Michigan. Dr. Milder holds over 30 patents as an inventor.

Ron Gehl, P.E. is president of EOS Research, Ltd., providing control and remote monitoring solutions for renewable energy and environmental protection applications. He has nearly 30 years of experience in environmental engineering, and in the automation of processes that function at the boundary between industry and the natural world. Ron holds B.S. and M.S. degrees in engineering from Rensselaer Polytechnic Institute, and is Chair of the ASES Solar Thermal Division.

Terry Moag is the CEO and Founder of Radiant Store Inc., a diversified company specializing in the areas of Renewable Power, High Efficiency HVAC, Combined Heat & Power, LED Lighting and Building Consulting. A Graduate of The Rochester Institute of Technology, and an accredited NABCEP Certified Solar Thermal Installer, Terry has over 25 years of experience in the Mechanical Contracting and Energy fields.

John Siegenthaler's full day session examines solar thermal in the context of modern hydronics, and includes applications for heat pumps and biomass boilers, within the context of hydronics. Many of the design concepts that apply to solar thermal applications also apply to air-to-water and geothermal heat pumps, as well as pellet-fired boilers and other wood-based boilers: Low temp. distribution system, thermal storage, DHW production, outdoor reset, high efficiency circulators, etc. We will demonstrate this commonality and address a range of renewable heat sources.

The Big Picture course aims to systematically describe, review and discuss the essential components of the modern high efficiency home. The synergistic collaboration between passive solar design techniques, active solar equipment, advanced HVAC technologies, building envelope options and passive & active ventilation strategies create a home that is highly comfortable, highly functional and economically attractive to run.

The course will discuss the following areas of their respective component of the modern home, offer a cost/benefit analysis and close with a complete financial review to show a 25-year ROI.

• Building Envelope
  • Insulation
    • Spray foam (closed cell, open cell)
    • Blown-in
    • Batt
    • Rigid foam (SIPs, ICFs, etc.)
    • Alternative (Straw bale, rammed earth, adobe, etc.)
  • Foundation
    • ICF
    • Frost protected
    • Foam lined
  • Wall construction
    • Thick walls: I-joists, wall trusses, Double-wall
    • Advanced Framing techniques
• Advanced HVAC Technologies
  • Heat Pumps
    • Geothermal
    • Air Source
    • Ductless
  • Combi-systems
  • All Electric
  • Biomass
• Passive and Active Ventilation
  • HRVs/ERVs
  • When is a home too tight?
  • Window placement techniques for passive ventilation
• Passive Solar Design
  • Comfort – why a passive solar home is the most comfortable home you can live in
  • Lifestyle – how passive solar strategies are designed around a family’s lifestyle
  • Traffic Pattern – efficient traffic patterns within the home
  • Daylighting
• Solar PV
• Solar Thermal

Olivia Cellini, PE is a licensed structural engineer, with over 15 years of design experience. Ms. Cellini’s firm focuses on three areas of expertise – structural engineering support for solar PV and Thermal installers, structural engineering for both residential and commercial buildings, and architectural design focusing on passive solar and “green” residential buildings.