Home Heating & Energy Blog

Evergreen Home Heating and Energy's mission is to make Puget Sound area homes the most energy efficient, comfortable homes in the country. Through our decades of knowledge and expertise, along with innovative and cutting-edge technologies, we believe we are the HVAC company that will make this goal a reality.

Innovation and Cutting Edge Tech Helps Homeowner With Water Heating Problem

July 12, 2011
We met a customer at the 2010 Seattle Home Show who had an unusual HVAC issue. They live in a condominium in West Seattle that was built 18 years ago and had a low efficiency gas furnace and a conventional storage type gas water heater. Conventional water heaters carry the risk of failure and leakage. This is a big problem in condominiums because leakage can damage the owner’s condo, and any condos below, which had previously occurred in their building.

Our customer is on the Advisory Committee that was created to come up with a solution to prevent this from reoccurring. While attending the Seattle Home Show, they talked with several of the HVAC contractors who had booths there (including our friends at PSE) and heard that tankless water heaters are the obvious solution to their potential problem.

The complication with that solution was that all of the lower and mid level condos had an existing furnace and water heater exhaust system installed that passed through the condo directly above it. The lucky owners on the top floor could install a new venting system for the tankless water heaters that allowed the continued use of the furnace exhaust venting system. However, the lower and midlevel owners did not have that easy solution.

That’s where we came in. We visited the site and found that each lower and midlevel unit had a combustion air duct that travels horizontally in the ceiling/floor system above to the outside. This duct conveys air into to mechanical closet that supplies the furnace and water heater. We determined that it would be possible to use that duct as a horizontal chase for the intake/exhaust pipes needed to install a Navien or Noritz tankless water heater. The problem with that installation is that the duct still had to convey air into the room to supply combustion air to the furnace and the exhaust pipe for the water heater would have to extend up the outside of the building to provide the necessary separation between an fuel burning exhaust and a gravity inlet into the building. This would not pass the Homeowners Association guidelines for the appearance of the buildings.

At this point our competitors where out of solutions. We at Evergreen, however, came up with a solution that not only allowed us to install a 95% efficient tankless water heater, but we were able to use the horizontal combustion air duct as a chase without any unsightly pipes visible on the outside of the building.

Rinnai makes a high efficiency tankless water with a single pipe exhaust/intake system. It has an inner and outer pipe and is a sealed combustion system. They also have a hydronic air handler that replaces a furnace and draws it’s energy from the tankless water heater. This system is so advanced that there is a priority switch that prevents the unit from heating while a bath or shower is being used so you never have to suffer through a lukewarm shower. So instead of heating the home at 70% efficiency and heating water at 60% efficiency, we are now heating both at 95% efficiency and we have a tankless water heater installed that qualifies for utility and state rebates and Federal Tax credits. Pretty cool, huh? It gets better. The air handler has an Electronically Commutated Motor (ECM) that uses 1/10th the power of the old furnace and is about 50% quieter in operation. Oh yeah, and no more leaking water heaters and no more water damage!

We are very proud of this installation and we have a very pleased customer. You can read their review of our company  here.

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