This week we’re retrofitting a very green heating system in a former summer cottage. Unico high-velocity low volume air duct system, low-mass Biasi boiler with Riello burner, flat plate high-efficiency heat exchanger for domestic hot water. The overall efficiency of the system should be in the very high 80s, and the best part? Our bid came in lower than another company’s proposal to install a conventional hot air furnace. Green doesn’t mean an arm and a leg. And it pays dividends for a long, long time.
The link accesses a New London Day article covering a Ledyard Zoning Commission meeting in which PV panels recently installed on the roofs of Town Hall and the Bill Public Library were described as “ugly” and as having no place in a historic New England Village. May the day never come, but PV naysayers in Ledyard are presumably not ready to return to candles and privies, are they? No. Thought not.
An interesting contrast appears when we examine Europe’s PV co-generating industry, actively supported by governments and utilities, in which panels are being installed on the roofs of buildings MUCH older than Ledyard Town Hall and Bill Library, with no objections from architectural purists. Britain’s Prince Charles exhorts owners of historic buildings in UK to refit them with energy features that make the buildings more liveable and energy-efficient, including roof panels.
A German study finds historic buildings apt candidates for energy retrofits and the mounting of panels, particularly flat roof PVs, and indeed, much of the architecture of Europe is older, but not likely to be torn down in favor of more modern, PV-friendly design.
Even the Vatican has installed an experimental PV array on one of their buildings, and advocates more energy equipment on Vatican rooftops, excepting possibly St. Peter’s Cathedral. I can see the point.
Few New England historic buildings retain their original cedar shingle roofs, and thatch never really caught on in the Colonies, for some reason. What we find on Town Halls and other public historic buildings is mostly asphalt shingles put there not to look good but to keep rain and wind out. We’ve gotten used to these modern roof coverings, and they’re now considered not jarring to historic sensibilities.
In time, we’ll come to view PV arrays as acceptable aesthetic on our Town Halls, and indeed, concerned citizens will learn to expect such things as signs of good stewardship from town officials and echoes of New England frugality, another historic value that could stand a revival.
The mess at left may not actually be so bad, but it could have been neater. Your electrical service, from the rooftop attachment (weatherhead) to the bottom of the breaker (or fuse) panel, is a critical and expensive part of your house infrastructure. It isn’t beautiful, but it’s important.
Keeping this system clean, dry and free of rust is worth paying some attention to. Ensuring that the service is grounded, either to a buried water pipe or to driven rods, is vital to your safety.
If you have an old fuse panel, do not despair. Fuses are in disfavor with inspectors and insurance companies, but fuses are not intrinsically inferior to breakers. They do tend to be older and more liable to fail, though.
Here’s a link to a site that gives the dope on panels, grounding, meters and upgrades. Please take a look and cast a critical eye on that grey box outside your house, along with any suspicious wiring. If you see anything you don’t like, take a photo and send me a comment.
In the last post we examined the elegances of Bilbo’s earth sheltered dwelling as described in The Hobbit. Careful construction and design can yield a home requiring little energy for comfort, snug and dry and spacious inside. Twelve dwarves, Gandalf and Bilbo could gather in the dining room to feast on Bilbo’s pantry without feeling cramped. Then they had a jam session and stayed up all night plotting Smaug’s demise and the division of an uncountable treasure. All carried out underground.
Living underground is not always so nice. Later in the story the travellers are waylaid by three trolls, and in due course the trolls’ cave is described. Not a nice place. Smelly, with stuff scattered about. Later, the group visit a goblin cave. Likewise, not a nice place. Wet, dark, confusing, windowless. That’s the dark side of earth sheltered living. So take care: while you’re being wooed by the fabulous energy profile of earth sheltered living, be warned about the several things that can go wrong.
Be aware that the concept of earth sheltered building does not rest on the insulating properties of dirt. The guiding principle, instead, is the thermal mass of the concrete membrane and the earth resting on it, enhanced often these days with layers of rigid foam board. The goal is to create a well-insulated envelope much like that of a conventional frame structure, but with a huge thermal mass on the inside of the insulation as well as on the outside.
Another unwritten but understood factor in American earth sheltered living is the electric heat added to the space by lighting and appliances. Without this incidental, or “internal” gain, the temperature of an earth sheltered dwelling would come to rest somewhere in the 50s. Call me a wuss, but I like to hunker down at home in less than a parka. And, notwithstanding the somewhat cheeky boast of earth sheltered builders that no hvac system is needed in their homes, most earth sheltered buildings feature a heat pump, furnace or stove to provide comfort as it’s needed.
Moisture, the bane of many an otherwise well built house, will kill an earth sheltered home. A perfect membrane is important for sealing the concrete against moisture, protecting the insulation and keeping the earth mass dry, . The low air change rate in a concrete, foam and earth envelope can result in a humid, moldy cave, the kind only trolls would want to live in. Forced ventilation through heat-recovery vent systems is an excellent idea. Meticulous construction featuring approved and inspected membranes and a drainage network is also fundamental to success in below-ground living.
One advantage modern earth sheltered builders have over Bilbo’s hobbit craftsmen is the technology that makes warmth, light, and air movement so much easier to design into a home. Skill with stone and wood will get you so far toward elegant American living, but without skylights, light wells, modern HVAC, kitchen equipment and tons of hot water, the idea of living in a well-designed cave would not appeal to most people. As it is, earth sheltered living is growing on us as a society, slowly. But that’s the pace of change in the American building industry. Slow. And cautious. I think I like it that way.
I wish you a lifetime pass on replacing the roof shingles on your house, but I”m a poor faerie godfather. Sooner or later it comes to all of us who own our homes. I did mine two years ago, and it wasn’t too bad.
When selecting a roofer, ask sharp pointy questions: what written warranty will accompany the shingles to be installed, what repairs to roof sheathing do you expect to do, what is the roofer’s personal guarantee if he/she wants to overlay new shingles over old, what is the wind rating of the new roof, and what color will complement the house and keep my attic cool all summer?
It is of this last question we will treat here. You know how hard it is to get a roofer to install light color shingles? You know how many major shingle manufacturers offer white or light colors? It’s part of the conservative ballast that holds the building industry down in trendy times when aluminum wire, plastic doors and paperboard siding threaten to run away with us all. It’s good to be slow about questionable trends, but it can be maddening when building science is ignored in favor of “the way we’ve done it all these years and what’s wrong with it anyway?”
Light colored asphalt shingles save energy. They aren’t perfect, but they make a difference. The temperature of your attic on a sunny day can reach 150 degrees F. or more. Wood starts to outgas and dessicate at high temperatures, and plywood is also susceptible to damage from repeated overheating. Still, perception and preference keep light colors out of fashion for roofing materials.
The discussion about roof materials as energy reflectors/absorbers is getting lively, but the shingle industry is responding to market forces that still prefer darker roofs, even in hotter southern climates. Coatings are available, but they’re not cheap and, like paint, they need to be renewed often. The truth is that shingle manufacturers haven’t really tried yet to give us highly reflective coatings on our roofing materials, mostly because we haven’t insisted. They listen, we consistently prefer darker shingle colors, they shrug and say to the nutty green guys, ” See? We give ’em what they want!”
But, as Seal in the link will sing to you, a change is gonna come. Some analysts estimate that a highly reflective roof coating saves more energy than a similar square footage of solar panels. That sounds extreme, but I can testify that the section of white (painted steel) roofing on my addition keeps the attic under that roof much cooler than the medium brown shingles over the main house. Yes, I lost that battle. The roof can be seen from the street,and the point was made rather forcefully to me by someone with overwhelming influence in my affairs that the house needs to look “right” from the street. Sigh…… ok. But perceptions do change, and we’ll be using highly reflective coatings on our roofs someday, as soon as they become fashionable. Until then, sad to say, white roofs just aren’t cool.