Saturday, March 27, 2010

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.


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!


Saturday, March 20, 2010

New Content on Build-It-Solar

Pop Can Collector From Sweden

A very nicely done aluminum pop/beer can collector.  Lots of attention to detail, and lots of good assembly pictures.  In Swedish, but the pictures plus Google translator make it quite readable.
Pop can solar air heating collectors force room air through connected columns of black painted aluminum soda cans.  The sun heats the pop cans and the heat is transferred to the air.  The even distribution of airflow and large heat transfer area should make them efficient collectors.
Details here...

Update on Chad's Solar Heating System
ChadUpdate.jpgChad has made a number of changes to his solar water and space heating system.  He has also logged and measured the performance of the system.

All the details and performance graphs...

Efficient Inflation System for Double Skin Poly Greenhouses
poly skinned greenhouses use two layers of poly with a small blower
inflating the space PolyBlower.jpgbetween the layers.  This gives you cheap double
glazing, and reduces heat loss.
Most of blowers are set up to run 24/7,
but this article shows a way to cut down the run time dramatically using a
small pressure switch and a very simple check valve.  With the check
valve, the blower runs only when enough air leaks out to the point of
needing reinflation.

Details here...

Facebook Page
I've put up a page for Build-It-Solar on Facebook. 
Basically I have no clue how this all works, so if you have any ideas for the Facebook page, please let me know.

We just broke 500 fans today, so have to be doing something right :)

Sunday, March 14, 2010

Massachusetts Zero Energy Challenge Winning Home

This is a very impressive less than zero energy home.  It uses a
combination of reasonable size, excellent thermal envelope, very
efficient appliances, some passive and some active solar heating, and a
PV driven mini-split heat pump for additional heat and cooling.

The end result is a true zero energy house that can be built within a reasonable budget.

I cover a few of the highlights below, but all the details on the house are in the article here...

The monthly performance chart below speaks for itself.  For the year 2009, the house produced significantly more energy than it used.

Double stud, R42 walls insulated with cellulose insulation.
R100 cellulose attic insulation.
Triple glazed R5 windows with R7 interior thermal shutters.
Very good infiltration sealing.
Emphasis on south windows for solar passive gain.
Concrete slab floors for heat storage thermal mass.
Solar water heating
Solar air heating collector to for additional space heating.
Exceptionally efficient appliances and lighting.
Heat recovery ventilation system.
Efficient mini-split heat pump for heating and AC.
4.9 KW grid-tied PV array supplies all electrical power and then some.

Double stud R42 cellulose insulated walls
Total cost of the house without land is $180,000.

Altogether, and exceptional house.

Thanks very much to Doug and Tina for providing this material.


Sunday, March 7, 2010

Spring Solar Projects

Solar Hot Water
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Now is a good time to study up on, and start building a solar water heating
system, so you can get it in this summer.
There are several high quality DIY designs that cab be built for inside of $1000. 

 Many solar water heating


Solar Greenhouse or Sunspace
 A place to grow some plants, produce some free heat for the house next winter,
or just a nice place to sit and have a cup of coffee with the newspaper. 

 Many Solar Greenhouses and
  -- ranging from $20 to $200,000.

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Passive and Low Power Cooling

 Here are many ways to keep your house cool, and at the same time save money
and reduce Greenhouse Gas Emissions.  Shading, whole house fans, landscaping, earthtubes, insulation and sealing, reflective and garden roofs, ...
Lots of ideas here.
 Passive (and
efficient active)

Solar Pool and Hot Tub Heating
PoolHeating.jpgHTML clipboard

 Solar pool heating is arguably the shortest payback solar technology.  
Take the chill off the pool, and be easy on the planet at the same time. 

 Solar pool heating

My favorite quote on solar pool heating from Tom Lane in the Home Power Article Pool Heating Article:
 "Three gallons of oil refined and burned provides 400,000BTU ... Once.
Three gallons of oil, made into a 4 by 12 foot solar collector, can provide
over 10 million BTUs per year ... year after year"

How about a Summer Outdoor Solar Shower?
This is a very simple solar project to get started with.  It can save energy and reuse shower water for plant watering while providing a nice outdoor shower experience!

How to build info for several outdoor solar showers...

Build Your Own Solar Electric System
Solar electric systems have become much easier to self install over the years.  If you are careful about the safety issues, and have done some home wiring, you may want to give this a try.  Plan it this spring, and build it this summer.

Details on my self installed system...

More on DIY PV...

Do a Water Conservation Project
Spring is a great time to get started on an outside water conservation project.
Dozens of projects described in detail here -- rainwater harvesting, greywater reuse,
rain water gardens, ...

All the details on water conservation projects...

Any other ideas --- make a suggestion.


Friday, March 5, 2010

Collector Absorber Fins from Tom

Tom Sullivan built a couple large water heating solar collectors.  To reduce the work involved in making the heat absorbing fins that go on the collector tubes, Tom built a very nice press to stamp out fins.

Tom has decided to make these fins available as a product from his UP Truck Center business.  He is offering fins to fit 1/2 inch and 5/8 inch tubing in lengths from 24 inches to 34 inches.  He also offers a sort of super fin option that achieves more wrap of the fin around the tube.  The prices are very reasonable, and I think this is a good option for anyone wanting to save some time on building the fins.

Here is the web page describing all the options and some notes on how best to install the fins...

Tom is a long time friend of Build-It-Solar, and has sent in detailed descriptions of some of his very well done solar projects...    Thanks Tom!



Tuesday, March 2, 2010

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 FogHarvesting.jpgfresh water from the fog.  Nets catch the fog and then channel droplets from the fog into a catch basin. 


Booklet on "Hot Water From Your Woodstove"
This is a good 45 page booklet from Lehman's describing a couple systems for adding a heatWoodStoveHotWater.jpg 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.


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


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


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