Green Building with SIPs

The construction and operation of buildings has a significant impact on the environment. Buildings account for 39% of total U.S. energy consumption and 38% of carbon dioxide emissions. Green buildings use less energy, reducing carbon dioxide emissions and playing an important role in combating global climate change. Buildings also use a tremendous amount of natural resources to construct and operate. Constructing green buildings that use these resources more efficiently, while minimizing pollution that can harm renewable natural resources, is crucial to a sustainable future.

Structural insulated panels (SIPs) are one of the most airtight and well insulated building systems available, making them an inherently green product. An airtight SIP building will use less energy to heat and cool, allow for better control over indoor environmental conditions, and reduce construction waste.

Green Building With SIPs White Paper(pdf)

SIPs Save Energy

SIPs Save Resources

Indoor Air Quality

Life Cycle Analysis

Case Studies

SIPs Save Energy

Building with SIPs creates a superior building envelope with high thermalresistance and minimal air infiltration.• Oak Ridge National Laboratory(ORNL) Whole-wall R-valuestudies show that a 4-inch SIP wall (nominal) rated at R-14 outperforms a 2×6 stick framed wallwith R-19 fiberglass insulation.

• ORNL blower door tests reveal that a SIP test room is 15 times more airtight than its stick framed counterpart with fiberglass insulation.
• Up to 40% of a home’s heat loss isdue to air leakage.
• SIPs have demonstrated amazingly low blower door test results when properly sealed. Based on the reliable performance of SIPs, ENERGY STAR chose to eliminate the required blower door test for SIP homes to meet ENERGY STAR standards.

SIPs Save Resources

The major components of SIPs, foam and oriented strand board (OSB), take less energy and raw materials to produce than other structural building systems. SIPs are also fabricated in a controlled environment, allowing for greater efficiency than site-built framing. The NAHB estimates that the construction of a 2000 sq. ft. home produces 7,000 lbs. of waste. SIPs have the ability to drastically reduce the waste generated during construction by using advanced optimization software and automated fabrication technology to ensure the most efficient use of material.

• OSB is manufactured from fast growing, underutilized, and often less expensive wood species grown in carefully managed forests. The OSB production process uses small wood chips and highly automated machinery, making OSB a very efficient use of raw materials.
  • About 85-90 percent of a log can be used to make high quality structural panels, and the remainder – bark, saw trim, and sawdust – can be converted into energy, pulp chips or bark dust.
• EPS is a lightweight insulation composed mostly of air. Only 2% of EPS is plastic. Over the lifetime of a house, the EPS insulation usedin SIPs will save many times the energy embodied in the petroleum used to make EPS (see Life Cycle Analysis for more info).
  • It takes 24% less energy to produce EPS than fiberglass insulation of equivalent R-value.
  • Scrap EPS generated during the manufacturing process can be recycled into new EPS products.

Indoor Air Quality

A SIP home or commercial building allows for better control over indoor air quality because the airtight building envelope limits incoming air to controlled ventilation. Controlled ventilation filters out contaminants and allergens, and also allows for incoming air to be dehumidified, reducing the possibility for mold growth.

There are a variety of ventilation strategies that can employed to provide fresh air to airtight homes. These vary by climate, but most are relatively inexpensive and operate on automatic control systems without the need for homeowner action.

SIPs do not contain any VOCs or other harmful chemicals that can affect occupant health. The components used to make SIPs (foam, oriented strand board, and adhesive) meet some of the most stringent standards for indoor air quality.

• EPS uses pentane, a non-CFC blowing agent that dissipates shortly after production. EPS has no offgassing and many EPS manufacturers are GREENGUARD certified
• SIP homes have qualified under the American Lung Association’s Health House® indoor air quality standard
• The adhesives used in SIP production do not contain any measurable amounts of volatile organic compounds (VOCs) that can be harmful to occupants
• Oriented strand board (OSB) does not contain urea formaldehyde adhesives and meets the world’s leading formaldehyde emissions standards, including the U.S. HUD Manufactured Housing Standard, the California Air Resources Board (CARB) Air Toxic Control Measure for Composite Wood Products  and the European EN-300 Standard

Build a Recycling Center

The most simple way to make your home “green” is to start at the most basic level and recycle. We all need to do our part to recycle what ever we can. Recycling is a big part of the future; many items are made from recycled products already, such as fabrics, bottles, outdoor furniture, even some clothes! Imagine what the inventors and designers will think of next! Honestly, I believe that the only way to make sure that we have a future with more “stuff” is to recycle. I know this involves time and storage space, but I promise we can make it as mindless and as attractive as possible. First of all, find out if your waste management company allows single stream recycling. If so, this is great news because you don’t have to sort any of your recycled products! But sometimes we aren’t lucky enough to live in these areas. So, maybe you live in a nice big house in the suburbs with a three car garage. This is perfect – you have all the room in the world (just kidding)! But at least you may be able to find room for attractive plastic bins to separate recycling into. I suggest getting containers that are similar to garbage cans and have lids; you may even be able to get color coded lids that have slots made for each item. Imagine how much this helps take the thinking part away from the process! Now, maybe you aren’t fortunate enough to have this as your living situation, which may require a little bit more space inside your home. But don’t worry, we can make this work. Several suggestions would be to head up to your local home store and purchase a “recycling” can that has two separate plastic containers that can easily be removed. If you buy two of these cans, you will be able to separate the main recycling groups; plastic, paper, glass and cardboard. But maybe this isn’t quite what you are looking for; did you know you can buy units to mount onto your wall? The doors can be pulled forward and reveal separate plastic color coded containers to sort recycling into. Wow! I guarantee that with this one, you will have everyone asking you what this item is on your wall. Imagine all the people you can get to join the recycling movement with a container like this! Do you recycle? Do you have a system that works for you?

Cost of Solar

Overview

The cost of a standard home solar electric system can be anywhere from $20,000 to $60,000 depending on these factors:

• System size
  A larger system will be more expensive and system size depends on how much energy you need. System size is the biggest factor that determines how much solar costs.
• Brand of equipment
  As with everything, some brands are more expensive than others.
• Equipment quality
  Less efficient solar panels are less expensive but you also will need to buy more to produce the same amount of power.
• Cost of labor
• Federal and local solar rebates

Larger state rebates make for a less expensive system. Most solar installation companies will let you pay the after-rebate price and then they'll take the rebate when it comes. In other cases you may have to pay the full price of the system and wait for the rebate yourself

The costs of solar energy can be high. Overall, the cost of a solar system is usually between $8 and $10 per AC watt and this adds up to a high total price tag. But, when you buy a solar system, you're paying in advance for 25-30 years of power.

When you think of it that way, the cost of solar energy is not much compared to what this power will cost from the utility company over the next 25-30 years. This is especially true when you think about solar as an investment in your home.

Plus, with new and innovative options for home solar financing, solar power can be surprisingly affordable.

Cost Breakdown

When you buy a solar electric system, here's where your money goes:

• Solar panels are 60% of the cost - they're mostly made up of pure silicon, which is expensive and takes a long time to make.
• The inverter makes up about 10% of the cost
• All the other parts, like wires and racking, is about 15% of the cost
• Labor is also about 15% of the cost

More Information

• Read about the federal solar tax credit and how it factors into the cost of solar.
• Learn how to save money on the upfront cost to go solar withSunRun Power Plan.
• Contact SunRun to find a solar solution for your home.

http://www.sunrunhome.com/

Alan Watts and 'Conversation with Myself' (part 3 of 4)1971

LED's Good Housekeeping Seal

By Eric A. Taub

Professional conferences always have refrains, leitmotifs that begin to define the thrust of many of the discussions. One of the popular ones at last week's Solid State Lighting Conference in San Francisco was, "We don't want to screw up like we did with compact fluorescents."

The point was that when compact fluorescent bulbs first hit the market, they were poorly engineered, overpriced and oversized alternatives to traditional light bulbs. They buzzed, created harsh light, took 30 seconds to warm up, and didn't last as long as promised.

The trick is how to avoid that problem with LED lighting, the technology that many believe will eventually replace most other lighting technologies in office buildings and homes.

As I've noted before, there is already plenty of LED junk for sale in the nation's home improvement stores. Many products use significantly more power than they claim and last a fraction of the time they advertise. At the conference, lighting designers chimed in to say that they rarely found LED products that performed properly.

"Some LED products are only delivering 30 percent of the illumination that they claim," said James Brodrick, the Department of Energy's solid state lighting head.

To stem the disaster of a potential consumer backlash against a technology that, done right, could have major positive environmental impacts, the D.O.E. is bringing LED lighting products into its Energy Star program.

Those products that get Energy Star certification will have to perform according to a set of Energy Department guidelines, as to the amount of light they produce and their effective life.

A handful (but just a handful) of products have received the Energy Star imprimatur. But Mr. Brodrick thinks he'll have up to 300 LED certified products by the end of the year.

If his agency pulls it off, it could help provide a comfort level for consumers concerned about new technologies. It's just too bad there's no Energy Star certification for price. With early LED replacement lamps priced at $60 a pop, the industry could use one.

Tips from SIPs architect

About 14 years ago, Bill Chaleff (Chaleff & Rogers Architects) designed his first structure with structural insulated panels. The system made immediate sense, so he got hooked. Today, he won't design a structure to use any other building system. Isn't that a little risky in the design sector, limiting your market like that? Apparently not, since Chaleff says, "We can't keep up with the demand." Right now, he's half way through the working drawings on a 48-unit affordable housing project for seniors. And an increasing number of clients are coming to him with commercial and institutional projects to be built with SIPs.

Over the years, Chaleff has learned how to optimize a design for the SIP building system. "When you fully understand how to use the product, it really sings. Unfortunately, we're not yet at the stage where most builders, designers and engineers are fully exploiting the capability of the panels in their SIP structures. Despite that, I eventually see SIPs as completely replacing stick framing." When asked to share design and building tips for working with SIPs, Chaleff offered the following:

1. "Use SIPs for your cathedral ceilings; they really shine here. People who just use SIPs in walls are missing out." Here's the dollar savings trick: bring your second-story walls up just five or six feet instead of a full eight feet or more. Then with a moderate roof pitch, you optimize the mix between square footage of panels installed to useful space created on your upper level.
2. While Chaleff says headers are regularly overbuilt in typical framed construction, he urges engineers and designers to use panels to their full potential; often that will either minimize or eliminate the use of headers and lintels. He also sometimes sees posts embedded in panels that are also oversized. "Insulspan has a wonderful bit of engineering, covering load-span tables and charts, that was written up by Thomas Bible. It includes a 40-page tutorial that is excellent. If people carefully put that in practice, we would have less over-building and less 2x lumber in SIP structures."
3. Where you have large cantilevers that need to hold up walls and roof systems and which would normally require added structural beef, Chaleff says you can save money by using panels instead.
4. Rooms with conventionally framed floors that are either above garages or are completely exposed to the outdoors often are the source of comfort callbacks. Chaleff uses SIPs for exposed floors and never has related comfort complaints.
5. Chaleff likes using the Endura roofing product over panels "because it gets rid of telegraphing at roof panel joints." Made of recycled materials impregnated with asphalt, the Endura product comes with a lifetime warranty.

Apart from these and other design tips, Chaleff believes the energy-saving advantages of SIPs will become more appreciated by prospective buyers as energy costs rise and general environmental awareness increases.

Instant Hot Water vs. Recirculating System

Many folks confuse the very popular, on-demand water heater with what a recirculating system can only provide. An instant hot water system does what it says - heating water right when there is a request for hot water ie. when the hot water is turned on at a plumbing fixture. In other words, the water is not heated and stored, but instead heated as needed. However, if the sink or shower at which you want hot water is some distance from the instant hot water heater, then the hot water line still has to be drained of the remaining temperate water that has been sitting in the line cooling after it left the hot water heater. With an on-demand recirculating system that temperate water is recirculated back to the hot water heater instead of being pour down the drain. Then once the temperature of the water in the supply line reaches the desired pre-set temperature, it allows that faucet to open up and supply the hot water to the end user. Imagine the water savings when you no longer have to let all that cold water pass down the drain while you’re waiting for the hot water!!!

COMPACT FLUORESCENT LIGHTS

There are a few important things
you should know about compact
fluorescent light bulbs (CFLs).
Very small quantities of mercury* are found in all
fluorescent light bulbs, including CFLs as well as the
types of fluorescent lights that have been in use in
offices, schools, commercial and retail establishments,
and residential basements for decades.

CFLs contain a tiny amount of mercury, typically
1/100th the amount found in old-fashioned
mercury fever thermometers.

CFLs provide important benefits in reduced energy
use (and lower energy costs), reduced greenhouse
gas emissions, and reduced local air pollution from
electric power generation.

Unbroken CFLs pose no threat of
mercury exposure.

Reasons To Build "Modular"

Speed:

• Construction is completed in 1/3 the time of site-built homes
• Construction of the home can occur while the foundation is being built
• House arrives in one piece, no waiting for certain materials or work crews to be free from other jobs

Affordability

• Controlled factory environment ensures guaranteed fixed pricing and no costly overruns
• Reduced on-site manpower
• Lower labor rates
• Minimal waste
• Minimal debris clean-up cost
• Less interest on construction loan
• Minimum of 15-30% cost savings

Exceptional Quality Control

• Modular Home passes numerous internal and third-party building inspections at all phases of production
• Home meets or exceed all federal, state or local regulations
• Tight quality control by manufacturer ensures safe and secure structures

Superior Materials and Manufacturing

• High-quality name brand materials used for construction (Moen, Anderson, Shaw, CertainTeed, American Standard, Merillat, Therma-Tru)
• Modular units are safely housed and assembled in climate-controlled factory
• Materials never subject to inclement weather, natural elements, vandalism or pilferage
• Homes delivered 85% complete, and erected onsite in hours

Durability

• Modular homes are built to last
• Withstands tramsportation to building site at speeds of up to 65mph (gale force winds) and crane lift onto foundation (earthquake conditions)
• Constructed with 30% more lumber, more glue and more nails than site-built home
• Unquestionably stronger than conventional stick-built homes

Outstanding Long-Term Value

• Endurance
• Reliability
• Minimal upkeep
• Longer life cycles
• Great return on buyer’s investment

Flexibility and Choice

• We offer vast range of choices for exterior treatments, customized interior features and accessories
• Large variety of house styles
• Custom designs or modified architectural plans
• Homes for all budgets and lifestyles

Drain-Water Heat Recovery (DWHR)

Any hot water that goes down the drain carries away energy with it. That's typically 80–90% of the energy used to heat water in a home. Drain-water (or greywater) heat recovery systems capture this energy to preheat cold water entering the water heater or going to other water fixtures.

How It Works

Drain-water heat recovery technology works well with all types of water heaters, especially with demand and solar water heaters. Also, drain-water heat exchangers can recover heat from the hot water used in showers, bathtubs, sinks, dishwashers, and clothes washers. They generally have the ability to store recovered heat for later use. You'll need a unit with storage capacity for use with a dishwasher or clothes washer. Without storage capacity, you'll only have useful energy during the simultaneous flow of cold water and heated drain water, like while showering.

Some storage-type systems have tanks containing a reservoir of clean water. Drain water flows through a spiral tube at the bottom of the heat storage tank. This warms the tank water, which rises to the top. Water heater intake water is preheated by circulation through a coil at the top of the tank.

Non-storage systems usually have a copper heat exchanger that replaces a vertical section of a main waste drain. As warm water flows down the waste drain, incoming cold water flows through a spiral copper tube wrapped tightly around the copper section of the waste drain. This preheats the incoming cold water that goes to the water heater or a fixture, such as a shower.

By preheating cold water, drain-water heat recovery systems help increase water heating capacity. This increased capacity really helps if you have an undersized water heater. You can also lower your water heating temperature without affecting the capacity.

Cost and Installation

Prices for drain-water heat recovery systems range from $300 to $500. You'll need a qualified plumbing and heating contractor to install the system. Installation will usually be less expensive in new home construction. Paybacks range from 2.5 to 7 years, depending on how often the system is used.

Automatically Preheat Water to Save Energy

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Usually when we are talking about plumbing fixtures for green building we are dealing with something that conserves water. But some plumbing devices can contribute to energy savings, as well.

When you are in the shower, the hot water from the shower strikes your body and transfers some heat before it falls away. But most of the heat in that water simply goes down the drain. Reportedly, 80 to 90 percent of the energy used to heat water for the shower is lost down the drain.

A drain water heat recovery unit (DWHR) transfers heat from water running down the drain to cold water going to the water heater. This preheats the water so that the heater is starting with warmer water, and thus needs less energy. A DWHR unit can save as much as 25-30% of the energy used for water heating, and payback periods range from 3 to 7 years, depending on use patterns.

Written by Philip Proefrock

The Costs of Not Building Green

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Despite the narrowing gap in cost between green building and traditional “to-code” building, most builders and home buyers still perceive the green option to be significantly more expensive. The reality is that due to increased builder education and an influx of affordable green building products, a building can be built green within the same budget as a non-green building. According to Clark Wilson, CEO of Austin based Green Builders, Inc., “It’s our job as builders to find those green products that don’t drive up the price of the home.” Rick Hunter of the St. Louis green building firm Sage Homebuilders agrees: “With proper planning and a little experience, building green, even certified green, can be done for about the same cost. We are building certified green homes at the highest levels of certification for less than 1% cost increase.“ For an informative breakdown on how green buildings cost from 0 to 2% more than non-green buildings, check out “The True Costs of Building Green” from the folks at Buildings.com.

Now that green building is an affordable option, it’s time to change the way we frame the affordability debate. Too long have supporters of green building been on the defensive, forced to justify the costs of building more energy efficient, healthier, more sustainable homes. Instead of focusing on the costs of making your building green, let’s talk about the costs of not building green.

Energy

For those strictly interested in a financial reason to go green, the energy savings of a green building speak for themselves. With the help of the EPA’s ENERGY STAR program, advances in energy efficiency have resulted in savings of 40 to 60% over non-green buildings. Greater focus on appropriately sized HVAC systems, tight construction and ducts, effective insulation, and energy efficient windows can save a significant amount of energy and money. Add in the water savings from low-flow fixtures, tankless water heaters, very efficient appliances, greywater systems, water-friendly landscaping, and rainwater collection systems and it’s clear how wasteful a non-green building can be. Save a little bit of money now by ignoring these green options and you could be throwing away money for years.

Health

You wouldn’t buy baby bottles with potentially harmful chemicals or toys with toxic paint, so why would you buy a whole house with both? Paints, adhesives, and caulks can all contain volatile organic compounds (VOCs,) the greatest causes of indoor air pollution in the home, which have been tied to increased asthma rates. Wood products in the home can contain urea-formaldehyde, a known carcinogen that is banned in Canada and Europe and soon will be on its way out in California. The Lawrence Berkeley National Laboratory studied indoor air pollution in homes and “found moderate to strong increases in respiratory and allergic health effects among children in homes with higher concentrations of selected VOCs.”

Companies that still manufacture products with urea-formaldehyde or other VOCs continue to do so because it costs them less to produce and consumers continue to choose the less expensive, but less healthy, choice. I’d like to think this is because of a lack of awareness of the health risks of such chemicals, rather than a conscious choice to expose their families to toxic chemicals. A green building not only reduces, if not eliminates, such toxic chemicals, it constantly cleans the air through efficient HVAC and ventilation systems.

The potential health risks of non-green buildings are reason enough for many to choose to build green.

Sustainability

Third in the green trinity is sustainability, the environmental cost of your building project. Green builders start by significantly reducing waste on building sites. While building materials that are not recycled or made from renewable materials might seem less expensive, the cost to the environment must be considered. And it’s not just the sustainability of the product that should be considered, but the company’s manufacturing process as well. Naysayers point out that individuals can do little to nothing to affect the environment, but if consumers begin to favor environmentally friendly products made from companies that have cleaned up their manufacturing process, including reducing waste and using renewable energy, then other companies will be forced to follow suit. Companies that have earned the Cradle to Cradle certification represent the height of sustainability.

If products were forced to label their environmental impact and embodied energy, consumers would think twice about many products. Green builders seek out durable materials that leave a lighter impact on the environment.

Parting Thoughts

The energy, health, and environmental costs make traditional, “to-code” building much too expensive. It will also be expensive for the builders themselves. As Rick Hunter points out, “Most builders have still not fully realized that we are entering a whole new era of building; the builders that make the changes now will be the ones that prosper, those that take the wait and see approach, will ultimately be hurt.”

The builders I know don’t like to be associated with anything shoddy or cheap, much less unhealthy, so it’s only a matter of time before green building practices are adopted as the norm. The term “builder quality” is used to describe the cheapest and lowest quality material available while still within code. Isn’t it time for builders to take back the term “builder quality” and make it something positive? Here’s your new slogan: Green: The New Builder Quality.

Written by Joel Bittle

Recessed Lights and Greenwash

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Recessed can lighting is a familiar method of lighting rooms. Rather than having fixtures protruding into the space, the light source is hidden in a recess in the ceiling, reducing glare. But, when the ceiling above is insulated, the can light fixture is a potential source of air leaks and thermal bridging.

I recently got a press release from a company advertising a product to quickly and easily “convert” recessed can lights to a pendant light look. But, after a brief look, it turns out to be a particularly bad case of greenwash.

Like sticking a ‘Hybrid’ label on an SUV to make it more efficient

The company advertises its product “reduces air leaks” around the recessed light, but there is no gasket or other means of sealing the cover plate, so it is unlikely to do much of anything in terms of reducing air leaks out of the box. More to the point, there is nothing that this kit does that addresses the original problem of an inefficient light fixture creating an insulation gap in the ceiling. In that way, this is like sticking a ‘Hybrid’ label on an SUV, or like putting a hybrid shell on top of a non-hybrid chassis and thinking that would make it a more efficient vehicle. It makes it look like the other, but underneath, none of the key issues have been addressed.

Their greenwash also notes “energy efficient lighting,” though there is no mention of how this increases efficiency. In fact, a recessed can fixture can be more efficient than a standard incandescent. Halogen lights are commonly available for recessed can lights, and are more efficient than standard incandescent bulbs. Rather than using the recommended 100 watt incandescent bulb the manufacturer suggests with the conversion kit pendant, a 60 watt halogen bulb would produce nearly the same light level and would last slightly longer than the conventional bulb. But halogen lights are generaly less attractive for direct view. The one pendant light fixture in my own house is one of the few places where I have not replaced an incandescent bulb with a compact fluorescent, and that is because it is directly visible.

Proper selection of recessed can lights

Greenwash aside, there are two kinds of recessed can lights: IC fixtures and Non-IC fixtures. Non-IC fixtures must have insulation kept from directly coming in contact to prevent overheating and the risk of fire. The IC fixture (the IC stands for “insulation contact”) is completely sealed and can have insulation placed right against it and on top of it. IC fixtures are also generally built tighter, with seals to reduce or prevent air leaks. In an insulated ceiling, an IC fixture should always be used, to allow the insulation against the fixture without any gaps that will contribute to heat loss. Non-IC recessed light fixtures are cheaper to produce, so naturally they are often found in homes where builders have cut corners to save money.

If you are building new, or are renovating, be sure to use IC fixtures where appropriate. But if the ceiling above a recessed fixture is another floor, the non-IC fixtures are adequate, and IC fixtures are not necessary. Removing and replacing a non-IC fixture in a ceiling is a good step to take as part of an overall home improvement to tighten the house against air and energy leaks.

If you like the look of pendants, this does offer an inexpensive (and reversible) method for getting the look without getting involved in a more extensive renovation. But don’t fool yourself into thinking that this is going to be a big energy savings step for you.

Written by Philip Proefrock

Life Cycle Costs

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One of the biggest concerns about changing to a green lifestyle is, of course, financial. How much does it cost to switch to a green lifestyle?

There is a perception that all of this must be very expensive, and that only altruists and tree-huggers can afford to live this kind of lifestyle. But a green lifestyle needs to be sustainable in all ways.

Something that is more expensive than its alternative will usually cost less in the long run. This is what makes evaluation of green products and green building materials so difficult. But looking at the life-cycle cost (the cost not just of purchasing the item, but also its operation and maintenance over its useful life) can show that the overall cost of the green option is usually lower.

Going green doesn't have to be an all-or-nothing proposition, and it doesn't have to be expensive. A recent article notes "Eco-Friendly Home Projects Can Be Cheap, and Also Stylish." While it is possible to spend hundreds of thousands of dollars on a green remodeling project, some influential steps, can be undertaken for only a few dollars. We've mentioned a couple of different checklists that can be used to start a green lifestyle and evaluate what steps you can take.

There's been a lot of talk about compact fluorescent light bulbs recently. It isn't just you should use these because they will reduce carbon emissions (though that is one of the reasons to use them). It's unlikely to expect that people will switch over for this reason alone. Altruism is a good thing, but most people switch over because the compact fluorescents also use less electricity. So a bulb that uses 14 watts rather than 60 watts is using only one-quarter the energy, and that translates into financial savings, as well as being better environmentally. And, because the compact fluorescent bulb lasts longer than an incandescent, there is less waste going into landfills, as well.

A lot of these steps can pay back their cost in a short period of time. Adding insulation to the house, installing and using a programmable thermostat, using EnergyStar appliances, are all good steps. If there is an energy benefit to choosing a green product, look at how quickly it will pay for itself. If $1000 of attic insulation will save $150/month in heating (and you have 4 heating months a year), then it will pay for itself in less than two years. Unless you expect to be out of that home in less time than that, it just makes financial sense to do the improvement, and gain the savings through lowered energy cost and lower energy use.

Written by Philip Proefrock

Drainage, Holes and Moderation

An edited version of this Insight first appeared in the ASHRAE Journal. Ever wonder how we can build a 50 story glass tower that doesn’t leak, but we can’t seem to build a two-story house that doesn’t leak? The answer is a little bit of counter intuitive thinking.

Ever wonder how we can build a 50 story glass tower that doesn’t leak, but we can’t seem to build a two-story house that doesn’t leak? The answer is a little bit of counter intuitive thinking.

We have learned to add holes and drainage in tall buildings in order for them to work. The lesson learned in tall buildings is that we can’t keep the rain out so we drain it out after it has entered. We can reduce the amount that enters but we can never completely keep it all out. Drainage and holes are key. These are regularly installed in tall buildings but not in short buildings. Until we add holes and drainage to small buildings they will continue to leak. This is so counter-intuitive that it borders on magic.

This story all begins with a cup in the rain (Figure 1). It is a plain ordinary cup, nothing magical about it yet. It is oriented parallel to the ground. Rain falls out of the sky due to something called gravity. The raindrops have momentum (“kinetic energy”) associated with them. There is no wind in this simple story of a cup in the rain so far. Sometimes the raindrops don’t fall completely straight down* and so they will occasionally fall into the cup. But lo and behold, even though some raindrops enter the cup the rainwater can drain out of the cup due to the slope of the cup with a little help from gravity. Drainage at work.

Figure 1: Cup in the Rain—Occasionally raindrops enter cup due to momentum and drain back to exterior via gravity and slope of cup. Did I mention drainage?

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