Verifying the Effectiveness of Our Solar Design
Thursday, September 23rd, 2010Darrel Kelly, John Rider and Joel Lemons arrived at our project site promptly at 11:45 am this morning to verify that the sun was now just starting to enter the house. Bryan was there exactly at that time as he was returning from a site visit to an ultra-green residential project up the pennisula.
Bryan ordered the remaining roofing materials from Ford Wholesale, and picked up sufficient materials to get started until the bulk of the materials are delivered to the project site tomorrow (Friday) afternoon.
Visiting An ‘Ultra-Green Project’
Bryan was fortunate to visit another project up the pennisula that is being completed. This project is very ‘green’ and has many similar construction components as our project, albeit on a larger scale. We are particularly interested in the finishing materials being used in this project and the mechanical systems layout.
One of the challenges with sustainable construction is identifying and procuring materials and products that are produced locally in a sustainable manner that do not contain harmful compounds. With our project, we need to specify the finishing materials and products that we require. For example, we need to prime and finish wood surfaces throughout the house. Also, we need fixtures and other products.
The surface area of the finished surfaces will be significant, so any off-gassing of volotile organic compounds (VOCs) is not acceptable. Identifying and procuring zero VOC adhesives, primers and finishes is important for maintaining high indoor environmental air quality. Essentially, we want to prevent pollutants from entering our home by not using products that contaminate the air inside our house.
Finding such products is difficult as the manufacturers of many products and materials bury the contents of their products in the MSDS (material safety data sheets) and it is time-consuming to research and identify acceptable products. And, then one has to procure those products locally.
it is much easier and faster to visit a project where robust research has been conducted already to identify and procure acceptable materials, including adhesives, primers and finishes. Bryan was fortunate to leverage such research on another project up the pennisula.
While at that project, Bryan reviewed the layout of the mechanical rooms. The site he visited has a ground source heat pump using geothermal heat exchange and a mechanical system that uses multiple heat recovery ventilators. The clothes dryers have booster fans and there is a whole-house water filtration system. All components that we require for our home.
The mechanical rooms were well-lit with waterproof fluorescent light fixtures. The layout of the room was simple and all pipes were labelled clearly. Interestingly, the ground loop had a filter system to ensure the water flowing through the system was clean and had no particles in it.
The ceiling was constructed such that sound (vibrations) would be isolated to the mechanical room and not transmitted to the occupied areas above. We need to consider sound deadening our West Mechanical room as our daughter’s bedroom is above the West Mechanical room.
Verifying the Effectiveness of Our Solar Design
The autumnal equinox occurred yesterday and our Green Rater, Darrel Kelly, came to our site at noon today to verify how much direct sunlight was entering our house through the windows. John Rider and Joel Lemons, both from Jrider+Design, joined us to review the construction progress to date. John did the original sun studies, using ArchiCAD.
Although Darrel, John and Joel subscribe to our construction blog and receive updates via e-mail, Bryan provided a brief overview of the status and project schedule. To understand if the timeline was acceptable, Darrel simply asked, ‘Will you still be married at the move-in date?’
The group went into the lower level and noted that direct sunlight was entering the building through the sliding glass doors on the East side and the casement windows on the South side. Bryan explained that we require solar gain in these locations because the earth is colder than the indoor desired temperature and, consequently, there is a heating load. Importantly, the direct sunlight makes the lower level much more pleasant and immensely more habitable. As the sun gets lower in the sky, the amount of direct sunlight entering the house in the lower level will continue to increase until the winter solstice.
Joel noted that the group should verify the amount of direct sunlight entering the house on the winter solstice. Everyone agreed.
The next stop was the roof, to review the construction details for the top layers of the gable roof. Bryan described the components and dimensions of the remaining layers of the gable roof (e.g., Cor-A-Vent, aluminum flashing, 1×3 furring strips, SecurRock, etc.). Everyone agreed that the design and materials would result in a robust and enduring roof, that would be easy to maintain and have a long life.
Walking on the roof to the front of the house, everyone observed the crickets and how the flat roof had a slight pitch in all locations that will direct water to the drains and eliminate ponding. Also, the brightness was observed and Joel commented on how this roof reduces the ‘heat island effect’ that is a problem in most urban areas.
Standing in the overhang of the gable roof in the Kitchen (over the garage), Darrel verified that a sliver of direct sunlight is now starting to enter the Kitchen. As the sun gets lower in the sky, more direct sunlight will land on the concrete floor in the Kitchen and create some solar heat gain. This is desired as the degree days increase after the automnal equinox.
Having verified everything at the site, the meeting moved to another location to discuss the subsequent construction activities and material selections. Bryan showed the group the sample of ducting manufactured by Zehnder that we are evaluating and considering for our house. The benefit of the ducting is that it is, like a plumbing system, very ‘tight’ and will allow us to use a heat recovery ventilator while utilizing displacement air ventilation. Ken Martin, from Silicon Valley Mechanical, is working on the design of the system.
Picking Up Securock from Ford Wholesale
To ensure the team from Earth Bound Homes can start first thing tomorrow morning, Bryan picked up 22 sheets of 1/4-inch Securock and three rolls of 20-inch aluminum flashing.
We’re ready to start the gable roofs tomorrow.
The filter (green) and pump (red) for the geothermal heat exchange system. Note the unstrut materials used.
Mythic multi-purpose primer in a 5 gallon container.
Rubio Monocoat Oil Plus finish, with 0% VOCs.
Joel Lemons (left), Darrel Kelly (taking photos) and John Rider (right) reviewing construction to date.
The supply and return lines on the West side of the house split into two ground loops, containing six piers in each loop.
John Rider reviews the work to date on the roof.
Roof access will be much different when the gable windows are installed.
Everyone liked the sidewalk repair on Winchester Boulevard. The pedestrians were happy, too.
Picking up Securock from Ford Wholesale in San Jose.
