By: Cynthia Hegg Krueger, Past-President (included in 4th quarter newsletter)
In my June column, I began an exploration of ways to “green” our homes and businesses. We covered the low hanging fruit, i.e. ways to tighten structures to minimize energy loss, followed by a brief discussion of ventilation (energy recovery ventilators). Most of the information in the June column had come from reading about and touring some of the six homes featured in this past summer’s Mission Zero Fest (MZF) in Ann Arbor (centered on Fountain St.). Most recently, the Remodelers Home Tour in Ann Arbor, Sept 28-30, 2012, revealed five of a total of 15 homes featured on the tour to incorporate some features of green building and sustainability. I find it really exciting to see the green trends catching on in the marketplace. One of the five homes referred to above is in my neighborhood, just down the street from my home. I’ve watched this project as it has evolved over the last year or two. When I toured the house in late September, I was able to see how the owner couple combined their ideal of the best living space with currently available green building technology to come up with their “dream home.” There are likely as many possibilities as there are, well, homeowners!
Many newer construction green homes are designed to take advantage of the most plentiful and readily available energy source - solar. More and/or bigger windows are designed on the south and west sides of the home, to take advantage of the sun’s heat and light during cooler months of the year. Longer roof overhangs and soffits provide more shade and protection from heat during the warmer months. Floors in areas where the sun shines in can be merely a concrete slab with a nice lacquer coating – concrete absorbs and distributes heat extremely well, helpful during the cooler months.
Geothermal heating, cooling, and hot water systems operate on the principle That water at a certain underground level maintains a constant temperature (45-58 degrees F) despite whatever surface weather conditions exist. This is due to heat produced by the earth itself. A pump is used to move fluid (usually water plus some alcohols) which has been heated (due to transfer from the underground heat) to an area to be heated. For cooling, the process works in reverse – fluid carries heat it obtained from a warmer room back down into the earth where the heat can be dispersed. Geothermal systems have some significant up front costs, but their efficiency leads to more rapid return on investment than most other types of heating/cooling systems. Four of the six homes available for touring at the Mission Zero Fest (MZF) had geothermal heating, cooling, and hot water systems.
Solar panel technology continues to steadily improve, and several of the tour’s homes had solar arrays as part of their green package. The arrays are typically placed on roofs; however the First Unitarian Universalist Congregation in Ann Arbor has their solar array located on a sunny prairie spot on their property. It is mobile; positioning itself to obtain the optimum angle for harnessing the sun’s rays. The homes featuring this green technology on the MZF tour were the ones achieving “net zero energy,” in that they produce more energy than they consume. The tour’s net zero home has an 81 kW rooftop solar array; the other tour home, which approaches net zero status, has an 8.6 kW solar array. Depending on the directional exposure of the home and the angle of the sunlight contacting the array, a solar energy installation can be an attractive option to home and business owners.
Another cool energy efficient technology I saw in one of the MZF homes was referred to as a “recirculating hot water ultra-efficient water distribution system.” The basic design differs from water distribution systems in older homes, where water is pumped from the source where it is heated around a piped circuit, off of which each faucet is fed. When you want hot water at one faucet, it must be pumped from the source around the entire circuit before it can reach you. In the above system, each faucet had its own plastic pipe circuit coming directly off the water source. This uses much less water, as well as decreasing the amount of water needing to be heated.
The above systems are typically put in during major remodeling/construction expounding about greener technologies, space and time constraints typically intervene, and my word limit is up! No more space for discussions of “glazed, low E argon filled glass” windows, motion sensor lights, smart thermostats (including remotely programmable units), low flow plumbing fixtures, and so many other green technologies continually developing for our use. May the force of green technology be with us always!!