Residential HVAC Solutions

 

Solar Hot Water - Viessman Systems

Rooftop solar panel to power Solar Hot WaterExecutive Summary:
Evergreen State Heat & AC got into the Solar Hot Water Tank installation & service business beginning May 2009.  Viessman is our brand of choice, which will be distributed via Gensco Supply.  Viessman makes the premium brand of matching solar panel and water tank equipment, which is our target market.  We've installed a pilot system in our shop at 2120 Pacific Ave., and shortly will be a Snohomish PUD certified contractor.

Benefits of Solar Hot Water to the Environmentally Conscious:

  • Reduced climate emissions & lower carbon footprint
  • Cleaner air & better quality of life
  • Independence from foreign oil
  • Local generation of power instead of through a centralized utility
  • Supports the local construction industry
  • Systems are small, modular (for growth), quiet, few moving parts

Economics:

  • Installation Cost – $10,000 to $12,000
  • Utility Savings (family of 4) – $250/year in gas, $350/year in electric
  • 30% federal tax rebate for domestic hot water on primary residence
  • $500 Snohomish County PUD rebate
  • Home value up 10-20X energy savings (up to $6,000)
  • Assuming electricity goes up 8%/year; 15-20 year payback
  • If swimming pool and/or Jacuzzi payback is reduced to 3 years
  • Commercially they work great for Laundromats, gym showers & kitchens

Solar Hot Water Tanks From Viessman SystemsViessman:

  • General – Cadillac system, highest efficiency, made in Germany.  It is the only manufacturing company that manufactures matching solar panels and hot water tanks.  Is an 8,000 person company that is 3rd generation privately held.
  • Viessman sells OG100/300 certified systems, which are critical for getting tax & utility incentives (OG100 plus 50+% of hot water requirements).  Customers and contractor have 1 point of contact with all equipment to simplify warranty issues, along with the piece of mind that system is fully integrated.
  • Viessman BTU/s.f. of collector are best in industry.  The collectors are closed loop not “drain back”.
  • Viessman sells both vacuum tube and flat place so customer does not get only 1 type bid (and some BS excuse that the other collector won’t work).
  • Germany – The nation gets 15% less sun than the Puget Sound on average, yet is the leading manufacturer and consumer of solar hot water equipment.

Sales Process:

  • Sales Interview – We go out to qualify suspect into a prospect.  Go over benefits and price range.  Notified prospect that an Installation Review will cost $150 plus tax.
  • Installation Review – We do the TSRF (Total Solar Resource Fraction) analysis with a Solar Pathfinder, reviews roofing stability, locates system, and routes the piping lines.  Give the prospect the final report.  Cost of Pathfinder is $300.
  • Sales Close – From our review we put together a proposal, and meet with the prospect.


Solemetric Sun-Eye for solar analysis for solar panel locationSolar & Site Audit:
  • Before giving a proposal our Solar Technician must come to your home or business to review your: TSRF (Total Solar Resource Fraction); roof condition; solar panel location; solar piping layout; and area for solar tank and controls with connection to your existing hot water system. The cost for this audit is $150 plus tax, which will be credited toward any solar purchase. For that audit you will get a full report from the technician.
  • TSRF (Total Solar Resource Fraction) In order to ensure that you are able to get the most heat from the sun, we will need to identify where the solar panels need to be placed. Our Solmetric Sun-Eye Solar Analysis Calculator delivers an innovative, accurate and site-specific solar and shading analysis. This innovative tool will be used to pinpoint the optimal location and orientation for your solar panel.

General Installation:

  • Internet is a very bad source of customer data as it is poorly policed and there are many claims which are unrealistic.  Performance of any system needs to be based on accurate TSRF along with equipment capabilities; so it is very location dependant.
  • Seattle sun varies greatly but averages 3.5 hours per day.
  • Solar hot water is much less dependant on sun than photovoltaic (PV) therefore much better application in the Puget Sound region.
  • Solar hot water function is to preheat and hold water before it goes through the tank or tankless systems.
  • Typical cost of install is:  40% labor, 25% collector, 10% storage; 10% piping & insulation; 15% other.  Price range is $8,000 to $12,000.
  • Typical home energy consumption is:  40% HVAC, 25% HWT, 18% refrigerator, 7% lighting, 5% cooking, 5% other.
  • To save money you can do piping first (including new construction), then system later
  • Best to undersize system, reduces possibility of overheating during summer vacation, etc. and lowers the initial cost (systems are modular for growth).  Typical person uses 20 gallons of hot water per day; one 40-tube collector serves 2 people.

Evaluating a Contractor:

  • References & company reputation (also certification, member ASES)
  • Warranty offered
  • Value added (free maintenances)
  • System Design
  • Performance Estimates
  • Appearance of panels & installation

Collector:

  • General: Two Types – Flat Plate (since 1980) which is cheaper but less efficient and heavier; and Vacuum Tube which is ‘state of art’ and performs better in cloudy or cold weather (10% more efficient).  Indirect heat with ethylene glycol as heat transfer fluid.  Glycol needs to be replaced every 8 years ($200 service call cost).  Best TSRF is on south facing roof at 32° tilt from the ground and no building or tree shadows. 
  • Viessman:  1 Vacuum Tube panel or 2 flat plates generate 60 gallons/day for 2 people (saves 40 KBTU/day).  Replacing a tube is $300 plus tax.

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Other:

  • A second tank is needed, the electric or gas tank cannot be used for solar, but rather is downstream in series from solar tank.
  • A pump & controls are needed for the glycol system.
  • Flow sensors & thermostats are needed on potable water side of system.
  • Roof mounting hardware is needed for collectors.  Need a roofer to install these.
  • Most systems need a “heat dump” in the plumbing system for hot days to avoid glycol overheat.
  • A mixing valve is needed to make sure that water going to house does not exceed 125°
  • Property covenants may be an issue for collector panels, much be checked by homeowner.
  • Systems needs annual FSM to check pH of glycol, pump, controls, clean collectors, etc.
  • These are heavy and may need a crane to lift collector panels to roof.

 

 



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