Nest Thermostats Facing Challenges

08 Jan

Nest, the company that makes what they claim to be the “next generation thermostat” is facing a few challenges. Out-dated HVAC systems, Wifi connectivity, and vocal, unhappy customers during a national cold spell  are in the forefront in today’s news. TechCrunch discusses the situation on a recent blog post here. You can learn more about the product and read reviews on Amazon – Nest Thermostat product info and reviews.

I seriously considered purchasing a “smart” Nest thermostat when we built a large addition on our home last year. We upgraded our HVAC system throughout the home. We installed a Carrier Infinity HVAC system and Mitsubishi Mini-splits. The Carrier is a 3-zone system and 3-thermostats; the mini-splits have their own thermostats. In our case, the cost of the Nest for the potential savings appeared questionable when compared to other energy saving investments and the respective ROI (6″ walls, insulation, smart building techniques, etc.). Today’s programmable thermostats are pretty good w/o being “smart” – the stupid things have worked (always) as advertised.

On Nest’s website they claim, “Programming thermostats is complicated and irritating – but an un-programmed thermostat can waste 20% of your heating and cooling bill. So the Nest Thermostat programs itself.”

Programming our standard thermostats wasn’t complicated or irritating – it was simple. One control panel programs all three; it took about 20 minutes. I focused on energy savings when I programmed them; tweaked them during the first few months. I likely have them set for less demand then the Nest would allow based on living habits; I only turn them up/down when I feel uncomfortable in the home. They appear to be saving us money without the need for software upgrades, wifi connectivity, etc.

WRT energy conservation and saving money, the smart thing to do is focus on containing the energy you generate; over insulate the attic, stop air infiltration, etc.

Simple is a solution.

Is Geothermal Always Worth It?

26 Oct

Earlier this year, I wrote a post on the Pros and Cons of Geothermal Heat Pumps (GHP). As it turns out, there is more to the story. I am in the process of evaluating HVAC systems for an existing home that is getting an addition. The addition is almost the size of the existing home; a new HVAC system is required as you can imagine.

After looking into several HVAC options with a focus on GHP, the consensus is to first focus on “tightening” the envelope of the existing home while considering the most effective methods of building an energy efficient addition. And, do this before worrying about your HVAC considerations. For my wife and I, it comes down to “first things first.” And, first on our agenda is “air infiltration” and insulation.

We are currently building an addition to an existing 1930s home. Understanding the energy use in the existing home and the addition we are building (or the home/addition you plan to build) is, IMHO, by far the most important aspect of HVAC considerations that come later. A “tight” home requires less energy to heat and cool, which in turn requires a significantly smaller HVAC system. And, what that means is a much lower overall energy bill.

It is important to note that lower overall energy use “increases” the “pay back time” required to recover the additional capital costs of a geothermal system.

Paying to “save energy” by investing in better windows, doors, and stopping air infiltration (conditioning your attic and crawl-space, for example), gives you the highest ROI (return on your investment). But, investing in “energy efficiency” leaves you with less money in the overall project budget. So, you need to consider this, is it better to invest in a GHP system or first invest in energy efficiency?

Cutting a big energy bill in half saves you a lot more money than cutting a relative small energy bill in half (basic math). For example, a poorly insulated home may have a $400/month energy bill on average, cut that in half and it saves you $200/month ($2,400/year). But, a “tight” home of the same size (sq. ft.) may only have a $150/month energy bill; cutting that in half only saves $75/month ($900/year).

Over the course of 1-year, the difference is $1,500/year and $15,000 over 10-years. My point here is if you have a well insulated home (SIPs, conditioned attic and crawl-space, great windows and doors, etc.), the initial capital cost of geothermal systems (GHP) requires a lot more time to “pay you back” because your overall energy use is low and so is your savings, in the short-run.

Say you have or plan to build a tight, energy efficient home and your monthly utility bill with a traditional HVAC system is projected to be the $150/month  example above. Say installing a GHP cuts that in half to $75/month. If the GHP system costs you $15,000 more to install than it takes over 10-years to “break-even” (I’m assuming the $15,000 in the bank would be worth more 10-years from now; maybe $20,000).

What I have concluded after a significant amount of research is this; a home that uses significantly less energy because it was built or remodeled to be very energy efficient may not benefit “financially” all that much from a GHP system due to the initial capital cost involved.

Unless you have a huge McMansion or you are using the GHP to also heat a pool, etc., may I suggest you run the numbers for your project? And, definitely consider the best solution of all, invest in cutting your total energy use by “tightening” up the home and stopping all possible avenues of air infiltration.

In short, first take a hard look at the energy efficiency of your home or project before considering any of the possible HVAC systems. There are several new HVAC technologies (mini-splits, high efficiency heat-pumps using air – traditional type systems) that are making GHP a hard sell for energy efficient homes of say 4,000 t0 5,000 sq. ft. or less.

Green Remodeling For Baby Boomer Homes

27 Jul

Remodeling a home is possibly one of the highest levels of “green.” It is one of the best sustainable housing initiatives around. While researching the remodeling industry I came across the website dubbed, Home for Life. The site includes a wealth of resources that explain opportunities to upgrade an existing home’s energy and resource efficiency to reduce environmental impact. The website is a product of Remodeling Magazine, a Hanley Wood publication. Read more

Best Available Research on Attic Fans and Power Ventilators

09 Jul

Do attic fans lower the cost of cooling your home?

Solar attic vents are not good for energy efficiencyAre solar attic fans worth installing? Common sense suggests they would be but are powered attic fans really a good idea for energy efficiency based on research and science? I have a master’s of science degree and my initial belief was it made sense. It just seems logical that a cooler attic would lower the cost of cooling the house in summer. While researching radiant barriers for the attic and reflective paint (Kool Seal Premium White) for our metal roof, I came across a few articles strongly suggesting powered attic fans were a dumb, and possibly dangerous, idea based on science. Here’s what I found so far and why I removed my attic fan:

  • The Scientific Spin on PAVs (powered attic ventilators – fans): Cooling off hot attics with powered attic ventilators (PAVs) seems like a good idea. After all, doesn’t cooler attic air mean less work for the HVAC system, longer shingle life, and reduced energy costs? Unfortunately that’s more myth than fact.
  • Drawbacks Of Powered Attic Ventilators:Powered attic ventilators, already suspected of using more energy than they save, can also create excess moisture, structural problems, discomfort, and combustion safety problems for home occupants, according to a recent study. John Tooley of Natural Florida Retrofit, and Bruce Davis of Alternative Energy Corporation’s Applied Building Science Center in North Carolina, presented “The Unplanned Impacts on Houses by Powered Attic Ventilators” at the 1995 meeting of the Energy Efficient Building Association.The paper describes research conducted on eight homes over a period of three months. As a result of this research, Davis said that he wouldn’t recommend the use of powered attic ventilators. He emphasized, “If someone chooses to use a powered attic ventilation strategy, they need to do additional performance tests and take responsibility to be sure that it won’t cause other problems.” The potential for hazardous conditions is particularly high in homes with combustion gas appliances, because the ventilators can create negative pressures that cause backdrafting.
  • Energy Star: Attic Fan Ventilation – Attic fans are intended to cool hot attics by drawing in cooler outside air from attic vents (soffit and gable) and pushing hot air to the outside. However, if your attic has blocked soffit vents and is not well-sealed from the rest of the house, attic fans will suck cool conditioned air up out of the house and into the attic. This will use more energy and make your air conditioner work harder, which will increase your summer utility bill.
  • Ask the Builder: Powered Attic Fans – Attic Insulation Facts: “I used to recommend PAVs [powered attic ventilators – fans] for houses, but I don’t anymore.”
  • Building Science, Unvented Roof Summary Article

The best solution appears to be making sure your attic is well insulated and well-ventilated using passive vents and natural air flow. Inspect your attic insulation and ventilation, or have a contractor do so for you. Just add more insulation or natural (passive) ventilation, if needed. Both measures will reduce the cost of cooling and heating your home; no electricity required and they are perfectly quiet.

ADDITIONAL ENERGY EFFICIENCY RESOURCES

  • Contact the local power company website and local energy associations for more information on constructing an energy efficient home in your area.
  • Building Science Corporation, Unvented Roof Summary Article: Excellent resource with in-depth research and hard-core science. Building Science is dedicated to teaching and providing factual information concerning building science and energy efficiency. This resource is used extensively by builders “in the know” when it comes to energy efficiency.
  • Building Science Guides and Manuals: Good place to start if you want reference documents for some of the most important building science topics.
  • Building Science Information Sheets: Fact sheets and overviews; another great place to start for those relatively new to the field.
  • Energy Star : The Energy Star website has extensive information on energy efficiency.
  • Geothermal Heat Pump Consortium: Geothermal is the most energy efficient method known today for heating and cooling. However, you will benefit by first making sure your home or building is insulated properly and as air tight as possible (within the limits of the appropriate building codes and safety concerns) before considering an expensive geothermal system.

ENERGY EFFICIENCY PRODUCTS

Whether or not you are using an attic fan and you own a fireplace, a great product to consider is a fireplace plug. Battic Door sells several energy conservation products including a simple fireplace plug; stops drafts and saves energy by sealing the chimney when not in use:

Fireplace Plugs Save Energy Stops Fireplace DraftsThe Fireplace Draft Stopper is an inflatable urethane chimney plug balloon pillow measuring 38″ x 16″. A round Fireplace Plug is also available. It is quickly and easily installed in the fireplace just below the damper level. The Fireplace Plug can be adapted to work in almost all fireplaces. Even if you have an unusual construction, the Fireplace Plug can be successfully installed in less than 2 minutes.

The Fireplace Plug is provided with 5 “slittable” areas that can be cut to provide an opening for a damper handle. As the Draftstopper is inflated it seals around the damper handle sealing the opening (helps reduce energy costs). Easy, quick and clean installation.

 

Will You Reduce Energy Costs by Painting Your Roof White

08 Jul

My metal roof was red, hot, and desperately needed painting. After spending some time inspecting the roof, I quickly realized how incredibly hot the red paint became even on a modestly hot spring afternoon. Why repaint the roof red since it gets so hot? I thought there must be a better solution so I started investigating roof paints. Fortunately, I wasn’t the only one wondering if a lighter-color roof would reduce heat gain inside the attic and save energy. Also, I quickly learned a lot about “reflective” paints, radiant heat, and the best ways to insulate the attic to reduce cooling and heating costs.

One research article I found informative and one I recommend reading is, Cool Roofs For Hot Climates by Dan Parker, a senior research scientist with the Florida Solar Energy Center (2003). The following is from the article:

Reflective roofs work because they stop the rooftop heat before it ever gets going. The sun’s rays hit the roof at the speed of light, and at the speed of light they bounce back into space. White or light-colored materials work best, but some new dark pigments reflect enough invisible infrared radiation to reject a lot of solar energy. And whether you’re applying tile, metal, membranes, or even asphalt shingles, choosing a more reflective version seldom adds cost.

The figure below graphically depicts the best solution for energy efficiency is a reflective white metal roof:

energy savings research white roof

After reading this article and numerous others, I painted my metal roof with Kool Seal® Premium White Elastomeric Roof Coating which I purchased at the local hardware store (ACE Hardward has it here in Richmond, VA).

Additional Metal Roof Information

Roof Costs and Energy Savings: According to the Metal Roofing Alliance, white-painted metal roofing has the highest solar reflectance value of any roofing product available and can save you up to 40% of your annual energy bills.

According to statistics from McGraw-Hill Construction Research and Analytics®, the number of homes with metal roofs has more than tripled over the past decade, moving metal from 3% of the overall U.S. market to 10%.

Some homeowners’ insurance programs allow discounts for homeowners with specific weather-resistant metal roofing products. Contact your insurance agent to determine if your home qualifies.

metal roof benefits fire resistant

Photo taken after the 1991 Oakland, California firestorm. Burning embers destroyed all of the homes in the neighborhood, except the masonry home that was roofed with Stone-Coated Steel Roofing.  While all of the neighbors fought (without success) to save their homes by watering down their asphalt roofs, burning embers did not ignite the steel roof. The house with the steel roof survived while all others around it were destroyed. (SOURCE: Metal Roofing Alliance: Lower Your Insurance with Weather-Resistant Metal Roofing)

Kool Seal® Premium White Elastomeric Roof Coating

FEATURES AND BENEFITS
(SOURCE: Provided by the manufacturer, see product description, surface prep, etc. here – PDF)

  • Energy saving up to 35%
  • Reflects 90%+ of the sun’s rays
  • Designed to be durable in any climate
  • Higher solids for better coverage
  • Forms a thick rubber-like blanket of protection
  • Expands and contracts – clings to your roof in all temperatures
  • Protects against moisture
  • Cured elastomeric film is mildew and algae resistant
  • Helps to absorb sound
  • Environmentally compliant
  • Soap and water cleanup – while wet

Energy Efficient Roofing Video by Tod Miller

Other Useful Articles Pertaining to White Roofs:

Geothermal Heat Pumps Helpful Videos

05 Jul

There are several helpful videos that explain Geothermal energy and the operation of geothermal heat pumps (GHP). Geothermal is considered the most efficient way to cool and heat your home or business with respect energy efficiency. As we come across geothermal videos we’ll publish them for you. Here’s what we have so far on geothermal:

 

 

Geothermal Ground Source Explained

 

People as well as Cars are getting Smart

30 Sep
More than four years after the market launch of the current generation the smart fortwo remains on the road to success. Until today over half a million models of the innovative two-seater have been sold. And sales continue to rise: since the beginning of the year 69,073 smart fortwo have been delivered to customers around the world, 6.6 percent more than in the same period last year.
“Our smart has long since evolved into an icon, which is indispensable in the cities of the world,” says Dr. Annette Winkler, Head of smart.
With the third generation of the smart fortwo electric drive smart is once again setting standards. It will be available for ordering from spring 2012. Those who would like to be among the first owners will have the opportunity to make a reservation online as of the fourth quarter 2011. For the further development of the car the company was able to integrate extensive experience of about 15,000 test runs and customer feedback from various electric mobility projects. For example, this is reflected in clearly improved range and engine performance. Read more

The Heat is On Energy Saving Tips by Family Circle

28 Sep

Hat’s off to Family Circle for publishing an energy saving article as fall approaches; good timing. Simple energy saving solutions can result in significant savings as we all know. The article, The Heat is On: and a Plan to Lower Energy Costs, offers a simple break-down of “Light Green, Medium Green and Dark Green” energy saving tips.

car2go First All-Electric Carsharing Fleet

19 Jul

OilObit.com News/Source: Daimler AG: SAN DIEGO – car2go N. A. LLC, a subsidiary of Daimler North America Corporation, announced that San Diego will be the first North American city to have a 100-percent electric vehicle (EV) carsharing program. San Diego Mayor Jerry Sanders, Nicholas Cole, President and CEO of car2go N. A. LLC, and Jonathan Read, CEO of ECOtality, made the official announcement at a news conference at the El Cortez this morning.

“We’re proud that car2go has chosen to launch the first North American all-electric carsharing service in San Diego,” said San Diego Mayor Jerry Sanders. “car2go’s launch here further supports our efforts to make San Diego the nation’s electric vehicle capital.”

The all-electric car2go program in San Diego is going to start operations before the end of 2011 with 300 smart fortwo electric drive vehicles. Read more

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