Posts regarding ‘Mechanical Systems’

Building Fundamentals: Engineering Fundamentals

April 22nd, 2010 by Clarke

This interview by Clarke Snell was originally published in the New Life Journal.

I moved to this region about 15 years ago because I thought it would be a better place to set up a homestead. I was looking for mountain spring water and milder temperatures than my Texas home. I found both, but the longer I’ve been here, the more I’m amazed by the people who live here, especially the ones I meet in my work in the world of “green building”. For my next few columns, I’m going to interview one of these local founts of wisdom on some aspect of all things green. This month, I talked with local mechanical engineer Jeff Buscher:

You and I are old enough to remember that ancient time before “green building” was a household word. How did you first get involved in the field?

I was studying architecture and engineering at Kansas State University when I read the book “Ecotopia” in an elective philosophy class. I remember it as a turning point for me. I started focusing on energy efficient technologies and sustainable practices in whatever way I could. After graduation, I worked for a large commercial engineering firm in Dallas for a number of years. It was frustrating because I kept pushing for sensible energy efficiency measures, putting them into designs only invariably to have them taken out at some point due to shortsighted reasoning, such as short-term construction cost reductions over long-term operating cost savings, let alone considering the additional environmental benefits. I finally decided to put my money where my mouth was and move to a smaller firm identified with green principles.

You and I have been working together for a while and I’ve come to really value your perspective. You’re unique in my experience because you combine an expansive knowledge of complex technology and technical methods with an interest in simple technologies, such as those commonly referred to as “natural building”. Given that novel perspective, what do you see as the important issues for “green building” enthusiasts to focus on?

First of all, we’ve got to face reality. The conventional construction world is in the grip of two dangerous forces: ignorance and inertia. Ignorance because efficiency has only been a concern for one generation.  We’re all still learning the best way to do this, but frankly, many building professionals aren’t educated as to even the most basic, common sense issues of building science. Inertia because to make money and avoid getting sued it makes sense to keep doing the thing that worked the last time. In other words, the construction industry is wary of innovation and slow to change. Real innovations tend to come from small companies that are light on their feet and driven through passion to do interesting things. Even in the “green building” industry most people are content to build to code. Forget codes. Building to code is the bare minimum acceptable to avoid being fined for breaking the law. To get where we need to be, we should be building at least two times in excess of current code mandated insulation levels. By achieving that level of performance we can significantly downsize or eliminate heating and cooling systems and make zero net energy buildings financially feasible. [Note: Zero Energy Design (ZED) can be defined as designing buildings that produce as much or more energy than they use.] ZED has been possible and achieved for decades. It’s not technically all that difficult to do.  It’s rare because it requires more design effort, and with current solar prices it costs a little more up front.  However,  the long-term benefits are huge. The question today is whether we can afford not to do it.

ZED is just barely starting to make it onto the mainstream radar. I think to a lot of people it sounds like something out of a science fiction novel. Can you shed a little light on the steps to move from conventional construction practices to ZED?

Well, it’s true that there is some high-tech involved, but many of the steps are old school. These concepts have been around for millennia.  First, we start with the land. Maximize what you can get from the building site and the surrounding area. Work with the sun for passive solar heating and cooling. Collect water on the site. Use as many materials from as close to the site as possible. Next, we need to stop building these light, expendable, giant boxes that pass for houses, office buildings, malls, what have you. We need more insulation and more mass. Insulation is a common concept for most people, but mass not so much. Adding heavy, dense materials (mass) adds to temperature stability and longevity of a building. This is a common approach in Europe, but we’ve missed the boat here.

In our climate, by creating a highly insulated building, you can drastically reduce the heating load, and by using a lot of mass you can potentially avoid mechanical cooling to keep the building comfortable. When compared to complex mechanical systems, insulation and mass are inexpensive and, once installed, they don’t require any additional input of energy to do their job. Past a certain threshold of load reduction, current “alternatives” such as solar electricity (PV), wind generators, solar hot water, and waste heat recovery start to become the sensible default solution rather than a luxury. This is where engineering becomes pivotal. Through energy modeling and integrating systems design with passive aspects of the building’s performance (insulation, mass, solar heating and cooling), we can create buildings that require only a fraction of the energy and resources to build and run compared to present common practice in this country.

The single variable that has the most effect on a building’s energy and resource efficiency is it’s size, so another major component of this strategy is to build smaller. Finally, we have to stop looking at our buildings as islands and start seeing them in their social context. A small, energy efficient eco-cottage is still missing the point if it’s part of a lifestyle that requires a two hour daily commute. Mixed use. Co-housing. Go local.  Live where you work.  Eat where you live. We should be designing to make driving less convenient and walking, and biking more convenient. I’m a big fan of the New Urbanism movement and recommend that people read up on it.

I’m with you on all of this, but one thing that makes me a bit nervous is our increasing dependence on complex technology. I’ve always been a do-it-yourselfer, but now I find myself spending more and more time in front of a computer whose inner workings are a complete mystery to me. That makes me fundamentally uneasy. What’s your take on the possibility of taking technology too far?

Obviously, that’s a danger. However, my personal feeling is that we need to find a way to solve our environmental problems while maintaining some level of the “comfort zone” that modern humans have become accustomed to. Technology can be a very useful tool in that context.  For example, in our climate, humidity is extreme. Around here, there is no way to create stable indoor humidity levels without some level of mechanical equipment. For me, the fun is in finding ways to limit and simplify the technology required to solve problems like this. I’m working on it, and I know others are too, so stay tuned.

To find out more about what Jeff thinks about, check out his blog at www.thinkorthwim.com and check out these sources of information that he recommends:

  • Walkable towns:  www.ecotownz.co.uk
  • Andrés Duany’s talk about how to avoid suburban sprawl:  www.youtube.com/watch?v=Ysoth-DYs78
  • ZED Architects in the UK:  www.zedfactory.com
  • Passive House Institute:  www.passivehouse.us
  • The Living Building Standard (No credits, just prerequisites.  It’s about what you did good, rather than being about what you did less bad.):  http://www.cascadiagbc.org/lbc
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Humanure: Goodbye, Toilets. Hello, Extreme Composting

December 12th, 2009 by brinker
(From Time Magazine)
By Adam Fisher Friday, Dec. 04, 2009

David Bailey helped install a composting toilet in Austin. Sawdust is used to eliminate odor.

For more than a decade, 57-year-old roofer and writer Joseph Jenkins has been advocating that we flush our toilets down the drain and put a bucket in the bathroom instead. When a bucket in one of his five bathrooms is full, he empties it in the compost pile in his backyard in rural Pennsylvania. Eventually he takes the resulting soil and spreads it over his vegetable garden as fertilizer.

“It’s an alternative sanitation system,” says Jenkins, “where there is no waste.” His 255-page Humanure Handbook: A Guide to Composting Human Manure is in its third edition and has been translated into five languages, but it has only recently begun to catch on. His message? Human manure, when properly managed, is odorless. His audience? Ecologically committed city dwellers who are looking to do more for the earth than just sort their trash or ride a bike to work. (See reusable toilet wipes as one of the top 10 odd environmental ideas.)

“It’s one of those life-changing books,” says Erik Knutzen, 44, an eco-blogger in Los Angeles. “You read it, and the lightbulb just goes on.” Now he eschews his porcelain potty for a big bucket with a toilet seat. He “flushes” by tossing in a scoop of sawdust, which not only neutralizes smells but also helps speed the breakdown of material for compost. Like many back-to-basics sophisticates, he believes Jenkins’ humanure system is more sanitary and more rational than the conventional alternative. “Human waste is a perfectly good source of an important resource, nitrogen,” Knutzen observes. “Water is a valuable resource too. Why mix the two and turn all of it into a problem?”

Wastewater treatment is much more energy-intensive than composting, which needs little more than time (about a year) for complete decomposition and pathogen elimination. In Austin, Texas, a sustainably minded nonprofit called the Rhizome Collective succeeded this year in getting the city to approve what may be the first legal composting toilet in the U.S. “The hypocrisy is amazing,” says Lauren Ross, 54, a civil engineer involved in Rhizome’s four-year battle to get a permit. “The city will buy you a low-flow toilet, but they’ll fight you all the way if you want to build one that uses no water at all.”

It’s an idea that you, dear reader, might be asked to take seriously. Not long ago, Nance Klehm, 44, a self-described radical ecologist in Chicago, invited her neighbors to stop using their toilets and start saving their poop. More than half of them — 22 of the 35 households — accepted her proposal. In three months she picked up 1,500 gal. (5,700 L) of excrement, which she’ll give back to participants this spring after she and Mother Nature have transformed it into a rich bag of fertilizer. “I’ve sent a sample in for a coliform test,” Klehm says. “There is zero detectable fecal bacteria.” (Read a brief history of toilets.)

At one point, Klehm invited her “nutrient loopers” to a potluck and was surprised to see who had agreed to participate. “It was the white collar people, not the ragtag anarchists. Mostly, they were delighted that they got this wacky proposal,” she says. “They didn’t know how to connect with the earth, but they could s___ in a bucket.”

Meanwhile, over in California, the Marin Composting Portable Odorless Outhouse Project, a.k.a. MCPOOP, is doing Klehm one better. The goal of MCPOOP (which is pronounced the Irish way as opposed to the rap-star way) is to get the government into the night-soil business and put humanure toilets in county parks and town squares. The group is less than a month old but already has the support of the local environmental establishment and Marin County supervisor Steve Kinsey. “The whole thing is like a good acid flashback,” says Kinsey. “We approved several experimental permits like this in the ’70s.” He estimates that a small-scale municipal demonstration project could be under way in less than a year. (Read “Is It Time to Kill Off the Flush Toilet?”)

MCPOOP was founded by a couple in their 50s. “We’re on a mission to re–potty train America!” says John Wick, a rancher in the western part of the county. “We’re going to start by replacing those nasty blue loos,” says his wife Peggy Rathmann, referring to two chemical toilets on their town’s main square. If that goes over well, they’ll replace the chemical toilets around Tomales Bay that kayakers often use. And then, who knows? Wick and Rathmann don’t see why every home in Marin County shouldn’t be humanure equipped.

To Joe (Mr. Humanure) Jenkins, nothing could be better news. “On a small scale, my system works like a dream,” he says. “But in order to do more research and development, I need to to collect humanure on a larger scale.”

MCPOOP and other projects are eager to help on the supply side. “We’re going to have plenty,” predicts Rathmann. “Tons of tourists come to West Marin, and they all leave us their poop!”

This is an expanded version of an article that originally appeared in the Dec. 14, 2009, issue of TIME

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Ground Loop

September 30th, 2009 by snugganut

Today, Tim, Billy and other volunteers installed a ground loop, which will be connected to the Energy Recovery Ventilator in the Mechanical Room.  These pipes will be filled with water, and will allow the ERV to take advantage of the constant temperature underground while supplying fresh air to the house.

Click here to view the entire Nauhaus Prototype Construction Chronology.

Ground Loop

Ground Loop

These lines will connect to the ERV.

These lines will connect to the ERV.

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Underslab Plumbing

September 29th, 2009 by snugganut

Today the underslab plumbing was completed.

Click here to view the entire Nauhaus Prototype Construction Chronology.

Ground Loop, Sewer, Greywater Lines

Ground Loop, Sewer and Greywater Lines

Plumbing in Mechanical Room

Washer, Tub Drain, Vent, Wastewater Heat Exchanger Stub-outs in Mechanical Room

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Vapor Barrier Under Footers

September 4th, 2009 by snugganut

Today a 20 mil. vapor barrier was laid in the trenches.  The concrete footers will be poured on top.   Radon pipes were installed for future venting if necessary, and greywater pipes were stubbed-out in hopes that one day a legal greywater system will be possible.

Click here to view the entire Nauhaus Prototype Construction Chronology.

View of Completed Vapor Barrier from Southwest

View of Completed Vapor Barrier from Southwest

tim vapor barrier

Tim Callahan

Stubbed-out Radon and Greywater Pipes

Stubbed-out Radon and Greywater Pipes

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EcoDrain Wastewater Heat Exchanger

June 23rd, 2009 by Seldom

We have received City approval to install vertical GFX heat exchangers like the Power-pipe. They will recover 50% of the heat in the hot water used for a shower. The only problem is that they are 5 or 6 feet tall (there are shorter ones but they aren’t very efficient), and they have to be installed vertically. That means we can’t recover heat from a shower located on grade without pumping the drain water.

Today, my horizontal wastewater heat exchanger prayers seem to have been answered. EcoDrain claims their 30″ long horizontal heat exchanger will recover up to 40% of the energy in a shower. My first thought was “well, that’s going to clog immediately,” but EcoDrain thinks I should relax:

The contact area of the horizontal EcoDrain drain is coated with a very slippery environmentally friendly non-stick coating. This prevents anything from sticking to the device and makes it self cleaning. For further assurance, it is possible to purchase a hair cover for the drain which dramatically reduces the amount of hair that ends up in the drain.

A 4″ diameter vertical GFX heat exchanger can be installed on the main gray water drain leaving a house to recover heat from all showers, the washing machine, and dishwasher, but the EcoDrain is sized for a single shower at a time:

A single EcoDrain can be used for multiple showers provided the showers are rarely used simultaneously. There is a limit to the maximum flow on the supply side and also an optimal flow on the drain side. If multiple showers drain at the same time, there will be diminishing returns in terms of savings because the heat exchanger capacity may be exceeded resulting in some water just passing through the heat exchanger without transferring any heat.

That’s fine with me. Our clients should be washing clothes with cold water anyway, and the dishwasher doesn’t use a lot of hot water. The clothes washer and dishwasher are also non-coincident loads. They fill with hot water. They do their thing, and they drain later. You wouldn’t be recovering heat unless you happened to be running some water while one of them was draining. Showers are what we need to recover every time. The other fixtures are good to pick up if it’s not any trouble.

The horizontal EcoDrain fits in a box 30” long by 6” high by 2” wide. It is designed to fit between a p-trap and a main drain line under the floor of the shower.

The vertical EcoDrain is a tube of diameter 3” and length 30”.

Pressure drop is about 5 psi.

The larger GFX heat exchangers are probably the way to go if we have a basement because they’re more efficient, but EcoDrain will come in handy when we have a shower located in the basement.

EcoDrain.ca

:: Inhabitat

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Daily Water Use

April 10th, 2009 by Seldom

Good Magazine has a good graphic showing relative water use of daily activities. This is just a corner of it. Click to view the whole thing

water-use

Avoiding meat saves a LOT more water than a low flow shower head or toilet.

Growing corn requires a lot of water too:

A gallon of ethanol, depending on irrigation practices, might require up to 2,100 gallons of water to produce. While, in areas more suited to corn production, it can take as little as 100 gallons of water to produce a gallon of ethanol. The worst news of all of this, is that from 2005 to 2008 water use for ethanol production increased 246%, whereas U.S. bioethanol production has increased only 133%. This means that corn ethanol production has pushed into land that is not well-suited for growing corn, thus increasing water use far more than it increased yield.

Ecogeek

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The System of Command

March 19th, 2009 by hana

The Greywater Powers That Be (or Be Not)

Red arrows indicate referral to another node of Greywater Power.

In our effort to design one of the first Passivhaus-certified residences in the country at “JJJ Ranch,” we are taking the same approach that we integrate into all of our high-performance natural building residential projects. In accordance with this holistic systems-design approach, we would like to incorporate a greywater system for landscape irrigation, in order to decrease potable water consumption for landscaping use, to improve the landscape and onsite food production quality, and to decrease the load on the sewer system.  At the outset of this research into the waste water policy of our State, we were already aware that the North Carolina 2006 Plumbing Code was the current code enacted at the state and county levels, and that this code defined greywater to be “waste water discharged from lavatories, bathtubs, showers, clothes washers and laundry sinks,” and that gray water was only to be used for flushing lavatories (not for irrigation). 2006 North Carolina Plumbing Code, Appendix C101

Our investigation into the existing code pertaining to a residential greywater system began by contacting the Buncombe County Permits and Inspection office. Our contact at this office sent us the 2009 Plumbing Code, in which there is detailed a greywater system for irrigation, much like an onsite septic field. When we inquired about the soil testing and approvals required within the code, this contact referred us to a Program Specialist at the Buncombe County Environmental Health Department, whose approval was necessary before a building permit could be approved. The Program Specialist informed us that a greywater irrigation system must be approved by the State Onsite Waste Water Department (under the NC Department of Environment and Natural Resources, DENR), and that OSWW would not approve such designs because waste water code does not distinguish between “black” and “grey” water—all must be hooked up to an approved septic system or field.

We then redirected our investigation to the state level and contacted the Plumbing Code Consultant under the NC Department of Insurance. This contact informed us that the design must be approved by DENR, and that they would most likely not approve it (again because Environmental codes do not distinguish between “black” and “grey” water). So, we contacted an Onsite Waste Water official under DENR. (Our email was intermediately redirected to a general Public Information Specialist at DENR, who referred us back to the Plumbing Code Consultant with whom we had spoken at the NC Department of Insurance.) The OSWW official that we had contacted informed us that we could either get approval through the OSWW Innovative & Experimental Systems Committee (under DENR) or through the Environmental Health Department, starting at the county level. The contact at I&E predicted that the design would not be approved, since the OSWW code does not recognize “grey” and “black” water separately, so we went back to the county level.

As we had already spoken to a Program Specialist at the Buncombe County Environmental Health Department, we contacted the Environmental Health Director, who after consulting with a Buncombe County Soils Specialist, informed us that the county is already approving the system described in the 2009 Plumbing Code, since any current building project would be finished after the code is to be enacted this coming summer.

So…it’s legal…?

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How Much Does a Shower Cost?

March 18th, 2009 by Seldom

A shower’s cost varies with water use, the cost of the water, inlet water temperature, the amount of energy used to heat the water, the cost of that energy, shower temperature, and sewer costs.

Imagine two neighbors. Each has a supply water temperature of 50°F, combined water/sewer charges of 0.28¢/gallon, electric rates of 8¢/ kWh, and gas rates of 60¢/therm. However, one has a low-flow showerhead on a water heater, and one has an old showerhead on an electric water heater. They both take 105°F showers, but because of the different water heaters and showerheads, the cost per minute of their showers differs by a factor of seven.

The neighbor with a low-flow showerhead rated at 2.5 gallons per minute (gpm) and a gas water heater with an Energy Factor (EF) of 0.6 can shower for just 1.6¢ per minute–0.9¢ for gas and 0.7¢ for water. The other neighbor, with an old 8 gpm showerhead and an electric water heater with an EF of 0.92, will pay almost 11¢ per minute for the shower–8.5¢ for electricity plus 2.2¢ for water.

During the time they run water to heat it up, they will both pay more per minute, since they will probably run all-hot water at a higher flow rate, perhaps running it at full blast through the tub spigot.

:: Home Energy Magazine

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The deKieffer Bypass

March 17th, 2009 by Seldom

The deKieffer Bypass is a transfer opening thru a wall behind the door trim. The top trim is blocked out 1/2″ on both sides, and a sheet metal boot keeps air from leaking into the wall cavity.

Fans of the deKieffer Bypass may also enjoy the Hofmeister Kink.

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