3 Ways to Save Energy That are a Bit "Out There"

Here are three areas where significant energy might be saved in a home with fairly simple systems.  One has to do with using some of the heat in the hot air up in your attic, and the other two have to do with recovering some of the heat we waste in showering.

Regular showers are a major waste of energy.  Typically we spend about 3 KWH heating water for a shower, and then send about 85% of that energy right down the drain.  It amounts to about 300 KWH for a family of 4 per month.

Using The Heat In Your Attic
This page looks at some of the ways that all that heat up in the attic might be used productively.  This includes recovering heat for domestic water heating, space heating, pool heating, and cloths dryer air preheat. 
Some of these look fairly practical (to me).

I've been logging the temperatures up in my attic for about 6 months and the plot of these temps is included.  We live in a very cold climate, and it still looks like there is some potential.

Details here...

Recovering Heat From Shower Water Drain Pipes
This page looks at all the energy we send down the drain when taking a shower, and in some of the ways that are currently out there to recover some of that energy. 
It considers one (as far as I know) new method, which is basically to rearrange the drain plumbing to retain the shower water in the homes heated envelope long enough to recover the heat in the water for space heating. 
Some ways of doing this, the resulting energy saving, and a small test to examine the potential of this method are discussed.

It may seem like there is not really much potential here, but for heating climates, the potential energy saving for a family might be of the order of 1200 KWH a year.

Details ...


A Very Energy (and Water) Efficient Shower Design
This is a look at a shower design that was looked at for potential use on very long range commercial jet airplanes.  It is a very efficient design both from a water use and energy point of view.  It may not be for everyone, but have a look.

Details...

So, I'm particularly interested in whether you think any of these ideas have some merit and are worth pursuing (or not). 
Or, maybe you have some of your own "Out There" ideas you would like to share?

UPDATE: Turns out Kenneth has built and uses a recirculating shower... 
Kenneth's interest were more in getting long showers with very high flow (6 shower heads) without breaking the bank on energy use.  Its a nice simple design.

Note that Kenneth has also done a very nice Solar Shed project that does both solar space and water heating -- hope to have the details on this up soon.
Thanks Kenneth!

Gary

Some New Stuff

This is just a collection of some interesting (at least to me) items added tot he site over the last week or so....

Harvesting Fresh Water From Fog
Areas with regular daily fogs (e.g. some coastal areas) can harvest impressive amounts of fresh water from the fog.  Nets catch the fog and then channel droplets from the fog into a catch basin. 



Details...

Booklet on "Hot Water From Your Woodstove"
This is a good 45 page booklet from Lehman's describing a couple systems for adding a heat exchanger coil to the firebox in your woodstove to heat water.  Good detail on both thermosyphon and pumped systems, and lots of information on troubleshooting and doing the installation safetly.




Details...




Skysails -- Kites for Towing Ships
These are large kites that can be deployed under favorable wind conditions to reduce fuel consumption.  With favorable winds, fuel consumption can be reduced as much as 50%.
Operation of the Skysails is largely automatic.




Details...



Homes From Cylindrical Grain Storage Bins
A collection of links to homes made from cylindrical steel grain bins.  These homes offer a thermally efficient shape, and some options for good insulation thickness -- plus and interesting look.

Details...









Gary

Zero Energy Homes for the Rest of Us

While visiting St George Utah recently, we found that we were in
town during the parade of homes, so we looked at a few of them.  One of the
display homes was a very efficient home built by Sun-Savvy Inc.  I was very
impressed by this home and the other homes they offer.

Their design combines a very good and very tight thermal envelope, heat
recovery ventilation, passive solar, solar thermal and PV arrays, and efficient
mini-split heat pumps to make a home that should be able to achieve net zero
energy use in the southern Utah climate.  The display home has a LEED
Platinum rating. 

Even more impressive to me is that these are very nice and very "normal"
looking homes.  These homes appear to be very easy for the homeowner to live with. 
While the energy efficiency does add some cost, the homes appear to be cost
competitive with ordinary construction homes.  In other words, these are
net zero or near net zero energy homes which should have a very wide appeal to
ordinary home buyers -- you don't have to be an eco-freak (like me) to like
these homes. 

We took the full tour, got a lot of pictures -- all the details here...

Much more on solar homes here...

Clerestory windows -- great daylighting.  These open automatically when a set temperature is exceeded.


The energy recovery ventilation unit -- an earthtube is used to precondition the intake air to the ventilator.

It seems like a lot of the "net zero" energy homes you see are a long ways
out of the mainstream -- they tend to be architecturally unique (some would say
strange) and come with an acre of PV panels that would add $100K+ to the cost of
the house were it not for some very very generous (and perhaps questionable)
rebate programs.  I don't see this type of near zero energy home ever
catching on and becoming widespread.  On the other hand, a design like the
Sun-Savvy homes seems like it could have very wide appeal.  I hope it turns into a trend.

Gary

Two Good Rainwater Harvesting Tank Ideas

Here are a couple nice ideas for tanks for rain water harvesting -- they are kind of at opposite extremes, but both well designed, interesting, and different than the usual rain water harvesting tanks you see.

The WooTank Two
This is a very nice tank design from Nathan.  The tank has an natural looking external frame made from 2 by lumber -- it looks great and would fit in very well with most landscaping schemes.  While Nathan painted his, you could stain it.  Nathan actually uses the tank as a large fish tank, but I think it would also work well for rain water catchment.  A tank like this can also be used as thermal mass to regulate and store heat from a greenhouse/sunspace, as Nathan shows in this earlier article... (pdf)



The tank walls are plywood.  The bottom is formed by concrete backer board that sits right on a thin layer of gravel over undisturbed dirt.  The tank liner is a single piece, EPDM rubber.  I think that this design is durable, efficient, inexpensive to build, and looks really good in the landscape.  All the details on the WooTank . 

Thanks very much to Nathan for writing this up and sending it in!




The FatBoy Water Wall Tank
This is another interesting rain harvesting tank.  If you are looking for something different than the usual cylindrical poly tanks, this might be for you.  They have a interesting , sculpted look.  Its a commercially available tank, and there are said to be several thousand installed.

Each tank holds 650 gallons and several can be stacked together.  I suppose they could even be used inside the house for thermal mass -- as in a thermal mass water wall...




Much more information on water conservation, rain water harvesting, grey water reuse,...


Gary

Energy Fairs

This is the season for a lot of the annual energy fairs, so check around and see if there is a good one to go to in your area.

The fairs are a great way to learn about renewable energy projects, go to workshops, meet some renewable energy people in your area, and find some deals.

I keep a list of all the Energy Fairs I know about here...

If you know of others that are not on the list, please let me know...

Gary