Attended an open house/ green building discussion at 419 Norwich Road in Salem CT yesterday. Jim Pepitone, green builder, showed off the distinctive features of the home, his second in this area, for sale at 359,000 on 4 acres of land. The link below is his first green project in the area, a few miles away in Montville…. The takeaway for this short post is: green features raise the price of a building by a smaller fraction than anyone would think, in this case about 10% overall. We’ll revisit this topic and point out things builders can do to inch toward energy-efficient building in a very conservative industry.
We’ve posted on tankless water heaters before, but an inquiry from a client prompts us to revisit some of our reservations about tankless units. Wonderful idea, of course, good for energy, wish i’d thought of it myself, and all; but do your homework and keep your eyes open. Claims made for tankless heaters are larger than they seem in real life.
First, flow rate. You need at least three gallons per minute of hot water at 125 degrees fahrenheit to operate a laundry machine, dishwasher, shower, kitchen sink or any combination of two faucets or appliances in the house. if your teenager is in the shower and you go downstairs to start the dishwasher, you will be cited by Family Services in this litigious society, for cruelty to a teenager. Sharing the output of a tankless electric unit is dicey. And families living in multi-bathroom houses will, sooner or later, need to share that output.
Second, power needs. The only electric tankless that begins to fill the bill for a family is something like the Bosch AE 125 . The power requirement of this water heater is app. 125 amps at full load. Do you have a 100 amp service feeding your entire house, as I do? Fuhgeddabouddit. You can’t install electric tankless in your house. Do you have a 200 amp service? Expect to give away 60% of that capacity while using hot water, which means that you can’t operate your electric range, air conditioning, and clothes dryer all in tandem with this water heater. You have to do what we call “load management,” in which you stop to think, ok, toaster is 110 watts, dryer 4500, range is 8000 unless I only use one burner, turn up the air conditioning thermostat, and,,,, ok, now we can do hot water. And if you have electric heat, you’ll have to shut some of it off to avoid an overload, even with a 200 amp service. No, you can’t have a 300 amp service on a house, not without paying lots of money. Perhaps in the “home of the future.”
If it’s just two of you in the house, or if the kids only come home for Christmas, this all may work out well. You can save up to 25% over electric tank hot water by virtue of lowering your standby costs (the expense of keeping the tank hot and losing heat to the surrounding air). If your house is large, full of kids, or if you have a big kitchen and you’re always in it, beware.
Electric tankless water heaters are growing in popularity, and they should. But i’m always concerned when a past or potential client buys one off the internet and asks for a quote to install it. My bill for installation will commonly exceed the cost of the water heater, if indeed I can even shoehorn it into the house’s electrical system. Then I’m delivering the bad news, the phone goes “click,” and the unhappy client is off down the road to a plumbing company which knows not-so-much about electrical loading and is willing to take the client’s money for installing an inadequately sized unit. Happens several times a year.
Other technologies are more practical. Oil, natural gas, LP gas, almost any fuel other than electric power makes for a better performance in water heating, due to the ability of those fuels to deliver larger amounts of energy instantaneously to the water, exceeding electricity by far in the critical category of “recovery rate.” Watch your loading, watch your pricing, beware of claims made by salesmen bearing gifts, and consider all your options. Sometimes a heavy insulation blanket and a simple timer can turn an old electric tank into a lean, mean green machine, for a lot less money.
The infrared photo at left shows radiant heat loss (yellow and red shading) in a typical residential window and door. It also reveals that the most grievous heat loss (purple, violet, almost black shading) takes place around the trim and edges of the opening. This is air infiltration, and it is your deadly enemy in keeping your house warm and dry and free of mold.
We’ve posted before on the hazards of air infiltration and moisture, and we’ve urged you all to arm yourselves with caulk, foam in cans, and sticky weatherstripping to fight the crannies that permit heat to escape and air to come in while you’re trying to heat or cool your house. Only in temperate spring and fall weather here in New England do we blithely throw open our windows and share the environment indoors and outdoors. In either high summer or deepest winter the potential for unpleasant temperatures and moisture accumulations indoors and makes climate control increasingly not just a luxury.
Enter the capitalist economy. Don’t fuss about with all that caulk and foam, say the strident voices on the radio and television; we can change your house’s energy performance in a jiffy with 1. new energy-efficient vinyl replacement windows, 2. new energy-efficient vinyl storm doors front and rear, 3. safe, energy-efficient blown-in insulation in attic and walls, no damage to your interior, 4. new, safe, “permanent” energy-efficient vinyl siding with optional foam insulation backing to save you lots of energy and money. And they take credit cards, and they have financial experts standing by to mortgage your house for the full amount.
No sudden moves, now. Will replacement windows perform startingly better than the wooden sash windows or vinyl double-hung you have now? Not if you reduce or eliminate air leakage ( infiltration) through and around your old windows. Then your old windows will perform nearly as well as any window on the market, give or take 15%. Surprised? Same story with the blown-in insulation and the vinyl siding. The best deal of the lot is the vinyl storm windows and doors. They reduce infiltration almost completely through your entry doors. The rest of the “home improvements” won’t pay for themselves any time soon.
The article linked here is from Journal of Light Construction on the subject of replacement windows and their rate of payback based on improved energy performance. The math doesn’t work. It takes a LONG time to payback the investment on new windows, doors, siding, and blown-in insulation. What takes a SHORT time to pay back? Anything that tightens your house, closes cracks, tightens doors and windows, and reduces air infiltration in and out. That’s the magic of home energy. Air. Stop it going in and out, you stop energy from being stolen from your house and your budget.
The boring conclusion is: nothing makes as big a difference in your house as caulk, foam and weatherstripping. Big ticket stuff like windows and viny siding works, eventually. But caulk and foam and gummy weatherstrip work today. If you hire a remodeler, handyman or do it yourself, it still works if you do it right. And it’s not too hard. Don’t hock the ranch before you’ve done the chores, ok?
But at your house, with four walls and your heating system between you and the howling wind, the math of heat loss makes a compelling argument for warm clothes and lower thermostat settings. If your walls are sealed and insulated to an average of R10 including windows and doors, and if your outside wall exposure totals about 3000 square feet including ceiling, the formula in the wiki link yields a heat loss of 18,000 btu per hour at ten degrees outdoor temperature and 70 degrees inside. Decrease that to 60 degrees inside temperature and the heat loss goes to 15,000 btu per hour. And, at 50 degrees inside, it drops to 12,000, a 33% decrease in energy loss. And Snuggies only cost 20 dollars US or so. And they make them for your dog.
You don’t have to work a miracle on your roof with PV panels, or smuggle some neutrons out of the Millstone power plant on your way home, or buy a miracle Shaker heater. You can work the basic math of heat loss with your thermostat settings. But you’re going to need some warm, comfortable clothes to stay happy and well. It doesn’t have to be a Snuggie, it can be a robe, vest, jacket or sweater. Or just a warm companion. That’s the best I know for empowering us little folks against the financial bind of winter in New England.
The diagram at left teaches you more than most folks want to know about boiler internals, specifically horizontal three-pass cast iron. There are many clever variations on the theme of torturing hot fumes before releasing them to the chimney and the heavens, and this one has been used for two generations in big commercial boilers powering factories and hospitals. Only lately do we rise above the heavy, hollow cast units many of you still have in the basement.
Don’t think me smug, I service boilers performing at 75% efficiency all over the county, and the Biasi in my attic gets around 87%. There’s not a huge harvest of energy to be reaped yet from changing boiler designs until we find a way to deal with the acids and sludge condensed in boilers at lower temperatures. In Europe they’ve refined the sulfur almost entirely out of their fuel, yielding something almost as clear as kerosene. The link is to a British site listing oil boilers boasting 97& efficiency. Shame on us Yanks. I won’t delve into the technology of boilers with condensing exhaust, but just imagine something vented through a light metal tube at less than 200 degrees, with sulfuric acid and dissolved ash dripping from a draincock on the flue.
My Biasi is among the high society of boilers sold in the US, but it hails from Italy. Its nearest competitors are made in Germany, Germany and Italy, respectively. There are American multipass designs being sold, but they lag behind in the critical qualities of low mass, low volume and low stack temperatures. Makes you think, don’t it? At app. 2.10 US dollars per gallon on Labor Day weekend, heating oil is as cheap as it’s been in years, and we Americans see no reason to respond, apparently, to anything but brute market forces. Price, in other words.
The little B4 model weighs in at 300 lb. dry weight. We hauled it up through the scuttle hatch with a light comealong rigged to a single unbraced rafter. Piece of cake. Why am I in such a lather to get it up there? It doesn’t require a conventional chimney (my house doesn’t have a conventional chimney), and the vent is through a single length of capped stainless steel chimney pipe extending through the roof on the leeward side of the house. It’s also within 6 feet of the blower unit that heats my house. The water heated by the boiler travels no distance at all, losing almost no heat to the surrounding air. It sits in a metal pan piped to a nearby sewer vent pipe.
For domestic hot water, imagine a stainless steel block heat exchanger the size of a shoebox hanging off the back of the boiler. When someone hits a switch either in the kitchen or bath, the control starts the boiler water circulating through the exchanger, heating domestic water in one pass hot enough to do dishes, shower or operate the laundry. But you have to hit the switch, otherwise the little Biasi sits there cold. Time to hot water, from a standing start? Three minutes by the stopwatch. I know, America can’t wait for its hot water, and can’t be bothered to hit a switch. But this is how it goes at my house. You get up to an hour of glorious hot water from a twist of the timer. Otherwise you wash your hands in cool or tepid water warmed a little by its passage through the house pipes.
Antifreeze protects the boiler, blower coil and heat exchanger from freeze damage, and the attic is insulated against bitter outdoor temperatures. I have to use a little pump, fashioned from an old oil burner, to lift fuel to the attic for the boiler. That adapted unit sits in the basement next to the oil tanks, pushing a dribble of oil up to a heavy steel reservoir which feeds the burner by gravity. My house, insulated through various remodeling projects over thirty years to respectable R values and tightness, will be comfortable this winter without any renewable energy resources other than some carefully planned passive solar (click to see an older post on our sunroom).
Will I put a system like this one in your house? Not until we talk. Talk a lot. Show me your old copies of the Whole Earth Catalog, or the original pulp-format Mother Earth News. Tell me you were at Woodstock, and why I didn’t see you there (I missed Woodstock, that’s why). Show me your green-friendly stock portfolio, your Energy Star appliances, your first pair of Birkenstocks. And assure me you’re willing to wait three minutes for hot water at any tap in the house, think before you hit the switch whether you really want to spend that energy, and let Dirty Phil into your house at least once a year for a boiler cleaning and efficiency check. And then, maybe. How can I be sure you’re ready to take this step? Soon I’ll be blogging about the solar hot water system that will be incorporated into my attic this fall. Stay tuned.
I put good filters into the HVAC equipment I install. Sometimes, on request, I install special electronic or ultraviolet purifiers that remove living thingies from the air inside your house. But that’s only inside. We can battle the pet dander, dust mites, pollen and even germs floating in your indoor air. But we can’t fight what ‘s going on outside.
The air quality where you live depends upon many things: surrounding plant life, animals living nearby, cities and manufacturing plants upwind of you, and nuclear testing in China, believe it or not. If you live just outside, say, Gary, Indiana, or on the east side of the Bronx, or in LA during smog season, you have to live with what man does to the environment in the course of American living: automobile exhaust, industrial emissions and the smoke from too many chimneys affect us when we breathe.
But I live in the country! Miles and miles of luxurious forest, hayfields, amber waves of grain, native casinos (non-emitters, they swear, very harmonious wit’ nature), placid cattle grazing in fields fenced by rubble-stone walls. I love New England. But the air quality where I live is not free of challenge. Ragweed, milkweed, conifer pollen, asters, wild grasses, oak and the cows’ behinds all emit stuff that I’m allergic to. On sultry August days I have to come inside sometimes to catch a breath of clean air. My house is not a clean-room, but it has a filtered air conditioning system that stands between me and the bad stuff outdoors sometimes when things build up and the Air Quality Index shows a high level of pollutants in the air.
If you’re not susceptible to these changes in air quality, good for you. But most people are, to varying degrees. Even stalwart smokers notice when the air gets heavy with dust, pollen and smoke particles, and breathing can be actually risky for more sensitive types like asthma sufferers.
What to do? I’m afraid the solution, like so much of life, involves work. To start with, clean your house. Really clean. Use a good vacuum, preferably a hypo-allergenic model, or even a HEPA quality vac, move the piles in the corners, move the couch, move the dog, and vacuum everywhere. Do the walls, too. I’ll wait while you finish.
And vacuum your bare mattress to reduce the number of dust mites living there. What are they living on, you ask? Read the Wiki thing in the link. Or don’t. Dust mites are icky. Just vacuum your mattress, under your bed, run your bedding through the dryer at high temp once in a while, or, better yet, hang it out on a hot sunny day. Dust mites are like vampires. Sort of.
And once y0ur house is clean, keep it clean. Fry your favorite greasy foods out on the grille rather than indoors. Use a non-ozone air purifier to filter one safe space in your house for you to lurk in on bad air days. Watch the weather thingie for air reports; they’re there, but barely. Don’t look for them in the shots of the weather lady’s legs.
And consider, charming as they may be, that your pets may be part of the problem. Especially if they share your furniture or your beds when you’re not looking. And they do, don’t they? Don’t lie. Of course you love your pets; but they might be as big a factor in your allergies as the ragweed pollen that’s out and bothering everyone now.
Respiratory health is not something you can take in pill form. What goes into your lungs can cause you trouble. Sometimes it comes from upwind, from the factory or the city. Sometimes it comes from the scenic fields and woods around your house. Sometimes it comes from the mattress under your sheets. Or from your dog. And if it’s coming from inside your house, there’s something you can do about it. Those fields may be best viewed through your windows until pollen season is over. Health is an energy issue, as we will see in future posts.
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.
The opening passage of Tolkien’s The Hobbit reads, “In a hole in the ground there lived a hobbit. Not a nasty, dirty, wet hole, filled with the ends of worms and an oozy smell, nor yet a dry, bare, sandy hole with nothing in it to sit down on or to eat; it was a hobbit hole, and that means comfort.”
I first read those words in the heady 60s, and at the time the building industry and the American worldview was far from ideas like passive solar, earth sheltering, or zero energy architecture. Bilbo’s hole was odd and faerie-like, and I had no inkling of how current, even futuristic Tolkien’s homey burrow would become.
To function as a cozy house, Bag End required an effective roof, partly of dry thatch(the porch roof), partly of green thatch, or sod. Rainfall was absorbed by the living sod roof and drained gently downhill toward the garden plants over a membrane of stone or cement, probably limed plaster (concrete featured nowhere in Tolkien’s Middle Earth, not even in Saruman’s dystopic industrial nightmare). Inside temperatures tended to settle at around 55 degrees, making active fireplaces a comfortable feature even in summer, at least in the kitchen where they were needed for cooking. Energy requirements were calculated, even in winter, against a tremendously reduced heat loss compared to a four-square above ground house of wood and stone.
The floor plan of Bilbo’s place took into account that three sides of earth sheltering left only one for windows and doors. The foyer, den, parlor and dining rooms were situated up front so that visitors, sitting next to the windows, could feel comfortable and not cooped up. Bedrooms, baths, storage and private spaces were off a hall extending “fairly but not quite straight into the side of the hill.” The refinement of light wells and skylights is not required for the hobbit lifestyle. Chimneys shot straight up through the thatch, capped to discourage rainfall, cleared of thatch in fall and winter to prevent fires caused by sparks.
Generous eaves over “deep set” windows kept out rain and snow, and provided shade for the summer sun directly overhead. In winter, the sun’s low, slanting rays entered the windows to light those front rooms, the hole doubtless being oriented to face south. The windows featured shutters which could be drawn against the weather and those pesky Black Riders if need be.
Light for late evenings was provided by candles and oil lamps, creating the need for ventilation without chilling drafts. The several chimneys, whether in use or not, provided a constant flow of fresh air pulled from the surrounding space, removing combustion by-products and biological smells of various types, including cooking odors. No use suffocating Mr. Baggins in his own house when we’ve already decided to send him off in pursuit of a dragon’s hoard and the lethal hazards of trolls, spiders, xenophobic elves and the searing breath of Smaug.
No well is mentioned in Tolkien’s tour of Bag End, but there were servants like Samwise Gamgee to draw water for cooking and baths, and it’s pretty certain that Bilbo got by on much less than the 90 or so gallons of water per day that a modern American needs to live comfortably. Vegetables and flowers shared the nurture of the green thatch roof and the surrounding plantings. No livestock appeared at all, though I suspect that Heidi’s goats could have grazed up there on the roof for most of the year without causing any trouble. Green thatch requires some tending, but not much, to stay vital.
Tolkien was only invoking the long history of European rustic architecture, nearly a thousand years in the making by the time he was crafting Bilbo’s burrow in the early 20th century. The basics of earth sheltered living are not at all new. The technology of earth sheltered living is a rapidly progressing project designed to furnish a below-ground house with the much desired features of the American lifestyle. More on that next time. Fancy a pipe on the porch? Smoking in Middle Earth is, I read, not bad for you at all.