Tankless water heaters

Tankless water heaters are compact units capable of providing “endless” quantities of hot water. Because they can be hung on a wall, they don’t require any floor space. These heaters can be fueled by natural gas, propane, or electricity.
June 02, 2009 BY Alex Wilson IN Tankless water heaters

Last week I suggested some ways to reduce your hot water use. This is almost always the easiest way to save energy with water heating—it’s the “low-hanging fruit” to be sure. Over the next few weeks, I’ll get into water heating options. To start, let’s look at the differences between “storage” and “tankless” water heaters.

September 06, 2012 BY Alex Wilson IN Tankless water heaters

There are two primary types of water heaters: storage and tankless. In this column I’ll try to explain the differences between these two approaches and offer some guidance on choosing between them. (There are also “hybrid” water heaters with features of both that I’ll cover in a future blog.)

Storage water heaters

Most water heaters are storage models. These are insulated tanks holding 20 to 120 gallons with either electric heating elements or gas burners. The storage tank stratifies with hot water at the top and cold incoming water at the bottom, so that as you draw off hot water (from the top), you get consistently hot water until the hot water is nearly depleted. The “first-hour rating” tells you how many gallons of hot water can be delivered in an hour. 

February 10, 2012 BY Martin Holladay IN Tankless water heaters

If you want to save energy, there are lots of exciting appliances and building materials that you might want to specify for your home: triple-glazed windows, an efficient refrigerator, and compact fluorescent or LEDLight-emitting diode. Illumination technology that produces light by running electrical current through a semiconductor diode. LED lamps are much longer lasting and much more energy efficient than incandescent lamps; unlike fluorescent lamps, LED lamps do not contain mercury and can be readily dimmed. lighting, for example.

When it comes to choosing a water heater, though, clarity evaporates. Simple, affordable water heaters aren’t very efficient, and efficient equipment is complicated and costly. So how do you go about choosing a water heater?

July 19, 2010 BY Scott Gibson IN Tankless water heaters

Tankless water heaters have one advantage over conventional storage units: no standby losses. Instead of keeping water hot around the clock, regardless of whether it's actually needed, tankless units heat water only when a tap or an appliance is turned on. By rights, this should mean lower energy consumption, a decidedly green advantage.

November 26, 2013 BY Rick DuRapau IN Tankless water heaters

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.

February 27, 2014 BY Alex Wilson IN Tankless water heaters

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?

December 02, 2009 BY Ed Welch IN Tankless water heaters

Five years ago, I completed a green remodel of my family’s home. We included green features like solar electric panels, a solar hot water system, recycled lumber, Trex decking, and many other green products. But since the remodeling work was completed, we’ve had years of consistently high propane bills, and I began to question whether my house is actually any greener or more sustainable that the average home.

July 01, 2013 BY Scott Gibson IN Tankless water heaters

John Metcalfe's San Francisco renovation included the installation of two tankless water heaters and a small circulation pump in his four-story, 3,200-sq. ft. home. The water heaters, connected in series, are located on the second floor, which is a more or less central location.

His hot-water problems should be over, right? Except they're not.

February 04, 2014 BY Carl Seville IN Tankless water heaters

As part of my renovation project, I needed to move the water heater out of its location in a below-grade recess in my crawl space that I was filling in to eliminate the need for a sump pump to get rid of water that collected. When considering the best type of new water heater, I considered both heat-pump water heaters and tankless heaters.

March 21, 2012 BY Carl Seville IN Spray foam insulation

I still remember using spray foam insulation in my early green renovation projects – it was almost magic! It sealed and insulated in one shot. It made it easy to finish attics and avoid most of the problems with fiberglass batts that were the common insulation on our jobs.

August 11, 2009 BY Rob Moody IN Tankless water heaters

In the last two blog posts, I shared highlights from a talk given by building scientist Michael Blasnik at the Department of Energy's National Weatherization Training Conference, particularly the problems with inaccurate computer models in determining weatherization strategies and effective home energy improvement measures.

December 22, 2008 BY Christina Glennon IN Tankless water heaters

Instant water heaters save energy and offer endless hot water, but not without some problems. A small tank and a big pump can fix the flaws

Ever been hit by a sudden blast of cold water in the middle of your hot shower, or even just lost hot-water pressure altogether, because someone has decided to do the dishes at the same time you're cleaning up?

December 18, 2008 BY Christina Glennon IN Tank-style water heaters

Learn how tank and tankless water heaters work, how to choose and size one to suit your needs, and how to save money and energy in the process

If you've ever been in the shower and shrieked in dismay when your spouse started up the dishwasher, author Dave Yates has some vital information for you.

January 12, 2009 BY Daniel Morrison IN Tank-style water heaters

UPDATED 04/05/2012

Tank or Tankless: Reduce the Load to Lower Water Heating Costs

April 06, 2012 BY Martin Holladay IN Tankless water heaters

Although tankless water heaters are, on average, more efficient than traditional tank-style water heaters, they’re also more expensive — so expensive, in fact, that many potential customers wonder whether their high cost can ever be justified by likely energy savings.

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