water heater

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Vermont Utility Makes (Another) Efficiency Offer

Green Mountain Power adds a water heater controller to previous energy-saving pitches to customers

Posted on Jun 22 2017 by Scott Gibson

On the heels of offering customers a deal on Tesla Powerwall 2 batteries and deep discounts on Leaf electric vehicles, Green Mountain Power is rolling out a new plan aimed at saving customers money and reducing loads on the grid.


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Image Credits:

  1. Aquanta

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GE Will Drop Heat-Pump Water Heaters

After a 2012 launch, sales prove disappointing despite efficiencies much higher than conventional electric-resistance water heaters

Posted on Sep 14 2016 by Scott Gibson

Improved energy efficiency, utility incentives, and a federal tax credit aren't going to be enough to save GE's GeoSpring heat-pump water heaterAn appliance that uses an air-source heat pump to heat domestic hot water. Most heat-pump water heaters include an insulated tank equipped with an electric resistance element to provide backup heat whenever hot water demand exceeds the capacity of the heat pump. Since heat-pump water heaters extract heat from the air, they lower the temperature and humidity of the room in which they are installed. .

According to published reports, GE Appliances will stop manufacturing the water heaters at the end of the year because of low sales, just four years after the energy-efficient appliances were introduced.

Editor's note: Since this story was originally published, there has been an important development, reported here: Bradford White Buys GeoSpring Rights and Equipment.


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Image Credits:

  1. Oak Ridge National Laboratory / CC BY-NC-ND 2.0 / Flickr

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How to Vent a Dryer

Can the exhaust from a clothes dryer be vented into the basement without creating major problems?

Posted on Aug 1 2016 by Scott Gibson

The exhaust from a conventional clothes dryer is full of moisture and lint, and the best place to vent it is directly outside. Matt Culik knows this, but his particular situation makes him wonder whether there are circumstances when this rule might be broken.

Culik will soon be moving into a new house, and the intended laundry room does not have a vent connection for a clothes dryer. Coincidentally, he is planning to replace an old electric hot water heater with a heat-pump water heaterAn appliance that uses an air-source heat pump to heat domestic hot water. Most heat-pump water heaters include an insulated tank equipped with an electric resistance element to provide backup heat whenever hot water demand exceeds the capacity of the heat pump. Since heat-pump water heaters extract heat from the air, they lower the temperature and humidity of the room in which they are installed. , and this has given him an idea.


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Image Credits:

  1. Tim Dorr / CC BY-SA 2.0 / Flickr

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Solar Ownership, New York Renewables, Wind Turbine, Water Heater Control

A roundup of recent developments in green building

Posted on May 31 2016 by Scott Gibson


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  1. 10 10 / CC BY 2.0 / Flickr

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Domestic Hot Water: No Perfect Solution

Gas or electric? Tank-style or tankless? It’s complicated.

Posted on May 13 2016 by Martin Holladay
prime

Some questions are easier to answer than others. For example, there is a fairly straightforward answer to, “How should I insulate the floor of my unconditioned attic?” — namely, “With a deep layer of cellulose.” (There’s more to say on the topic, of course — but even a full answer isn’t very complicated.)

There is no easy answer, however, to, “How should I heat my domestic hot water?” Every type of water heating technology is flawed; every solution involves compromise.

Many factors affect the decision about what type of water heater to choose, including:


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Water Heaters Get an Efficiency Makeover

New standards from the Department of Energy will kick in on April 16, with big changes in store for those over 55 gallons in capacity

Posted on Mar 26 2015 by Marianne DiMascio

From the rustic 1850s pump shower to the 1920s Humphrey automatic to today’s modern units, water heaters have made great strides in performance and efficiency. On April 16, water heaters will take the next great stride when manufacturers must comply with new Department of Energy (DOEUnited States Department of Energy.) efficiency standards.

The most common water heaters manufactured on and after this date will get a modest boost in efficiency, while units over 55 gallons will shift to next-generation technology, cutting utility bills by one-fourth to one-half depending on the technology.


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Image Credits:

  1. Tomwsulcer / Wikimedia Commons

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Heat-Pump Water Heaters in Cold Climates

Heat-pump water heaters save energy on a year-round basis — but during the winter, the energy savings will drop

Posted on Mar 6 2014 by Alex Wilson

In last week's blog I wrote about the GE GeoSpring heat-pump water heaterAn appliance that uses an air-source heat pump to heat domestic hot water. Most heat-pump water heaters include an insulated tank equipped with an electric resistance element to provide backup heat whenever hot water demand exceeds the capacity of the heat pump. Since heat-pump water heaters extract heat from the air, they lower the temperature and humidity of the room in which they are installed. in our new house — first, why we decided to go with electric water heating over solar thermal (since we use solar to generate as much electricity as we will consume), and then how we decided on a heat-pump water heater instead of one of the other electric water heating options. This week, I’ll get into a little more about heat-pump water heaters and some of the issues that come into play when installing them in cold climates.


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Image Credits:

  1. eMonitor data, Alex Wilson

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Deciding on a Water Heater

Why we chose an electric water heater instead of a solar water heater

Posted on Feb 27 2014 by Alex Wilson

As we build more energy-efficient houses, particularly when we go to extremes with insulation and air tightness, as with PassivhausA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. projects, water heating becomes a larger and larger share of overall energy consumption. In fact, with some of these ultra-efficient homes, annual energy use for water heating now exceeds that for space heating — even in cold climates.

So, it makes increasing sense to focus a lot of attention on water heating. What are the options, and what makes the most sense when we’re trying to create a highly energy-efficient house?


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Image Credits:

  1. Alex Wilson

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Do Combustion Safety Testing Protocols Need Fixing?

Dr. Vi Rapp of Lawrence Berkeley National Lab says one test in particular doesn't help as much as we think it does

Posted on Feb 26 2014 by Allison A. Bailes III, PhD

Burning fuels inside a house can lead to serious health and safety problems. That's why energy auditors perform a variety of combustion safety tests to find potential hazards and recommend fixes.

A couple of weeks ago at the Dry Climate Forum, I heard Vi Rapp, PhD, from Lawrence Berkeley National Lab (LBNL) make an argument for changing the way we do combustion safety testing. It turns out that one of the tests we do may not be as helpful as many people think it is.


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Image Credits:

  1. Energy Vanguard
  2. Dr. Vi Rapp

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Point-of-Use Electric Tankless Water Heaters

Now that I have installed several of these small, efficient water heaters in my house, I am an evangelical convert to the technology

Posted on Nov 26 2013 by Rick DuRapau

A couple of years ago, I was standing at my kitchen sink, idly waiting the minute or so for hot water, noticing my poor parched backyard. Central Texas was (and still is) in the death grip of a prolonged, severe drought. Our lakes are in really bad shape, and we are under very tight water restrictions.

Then suddenly, I had a mini epiphany: I’m wasting a lot of valuable water while I wait for hot water.


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Image Credits:

  1. Rick DuRapau

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