The most recent blogs at Green Building Advisor

Should I Insulate My Cold Water Pipes?

Posted on March 18, 2014 by Erik North in Guest Blogs

Insulating the hot waters pipes in your house is something of a no-brainer. Why let the heat escape willy-nilly? Pipe insulation is inexpensive, and the project is one that any homeowner could finish on a Saturday afternoon.

Whether to insulate the cold water pipes is less clear-cut. The project is still pretty inexpensive and easy — but does it have a point? Insulation retains heat, and these are cold water pipes. So why do it?

A Construction Trade Fair in Germany

Posted on March 17, 2014 by Andrew Dey in Guest Blogs

I recently attended BauTec, a trade fair for the construction industry that is held annually in Berlin. According to the show’s marketers, BauTec is “the year’s most important trade industry event.” I found the show to be impressive, inspiring, and overwhelming.

When the Gas Pipeline Shuts Down

Posted on March 14, 2014 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

In the wake of the recent military crisis in Crimea, energy experts have been discussing whether Vladimir Putin will be tempted to gain political advantage by shutting the valves on the Russian natural gas pipelines that supply Ukraine and Western Europe. Regardless of whether this scenario is likely, such speculation raises the question: How would urban residents in a cold climate cope if the supply of natural gas were suddenly turned off?

Going High-Tech With an Induction Cooktop

Posted on March 13, 2014 by Alex Wilson in Energy Solutions

One of our early decisions in the planning for our farmhouse renovation/re-build was to avoid any fossil fuels. If the State of Vermont can have a goal to shift 90% of our energy consumption to renewable sources by 2050, we should be able to demonstrate 100% renewables for our house today.

New Englanders Love Heat Pumps

Posted on March 12, 2014 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

Last week I went to NESEA's Building Energy conference, and I think I heard three terms more than any others: heat pumpHeating and cooling system in which specialized refrigerant fluid in a sealed system is alternately evaporated and condensed, changing its state from liquid to vapor by altering its pressure; this phase change allows heat to be transferred into or out of the house. See air-source heat pump and ground-source heat pump., net zeroProducing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines. Calculating net-zero energy can be difficult, particularly in grid-tied renewable energy systems, because of transmission losses in power lines and other considerations., and passive houseA 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.. (The second most popular trio was beer, wine, and whisky, but that may have something to do with the folks I was hanging out with.)

So let's get right to the important question here: Why do these people in the cold climate of New England love heat pumps so much?

Settling In to My Renovated Cottage

Posted on March 11, 2014 by Carl Seville, GBA Advisor in Green Building Curmudgeon

I’ve been living in my renovated house for about two months now, and, with the exception of my hot water issue and ice on my windows, everything is working pretty well.

HVAC for a ‘Pretty Good House’

Posted on March 10, 2014 by Scott Gibson in Q&A Spotlight

Matt Mesa is looking ahead to retirement in a new, one-level house in Hood River, Oregon. It's going to be a Pretty Good House, a phrase coined to describe a well-insulated house of an appropriate size.

All About Washing Machines

Posted on March 7, 2014 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

About 82% of U.S. homes have a clothes washer. Each of these appliances is used, on average, to wash about 300 loads of laundry per year. On an annual basis, residential clothes washers use more energy than dishwashers but less than refrigerators.

Heat-Pump Water Heaters in Cold Climates

Posted on March 6, 2014 by Alex Wilson in Energy Solutions

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.

How to Make Your Dumb Heat Pump Defrost Intelligent

Posted on March 5, 2014 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

Heat pumps can get frosty when they run in heating mode. It doesn't happen all that often, but it's a fact of life when you're trying to extract heat from cold, outdoor air.

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