Craigslist to promote causes or ideas

It looks like Craigslist can be used as a free way to promote causes or ideas.

I found this link: http://reno.craigslist.org/grd/3258942054.html in my traffic report the last few days -- it is basically a person in Reno who built the solar heated stock tank, and is using Craigslist to tell people it works fine and that he recommends.

This seems like a pretty good way to get the word out on good projects or good ideas?

Don't know what the Craigslist folks think of using this approach?

Gary

Increasing AC Efficiency Using Evaporative Cooling of Condenser Coil

This project from Chad adds an evaporative cooler around the outside of a conventional outside AC condenser coil.  The evaporation of the water in the cooler pads cools the air going into the condenser coil and substantially increases both the capacity and efficiency of the AC unit.

Evaporative cooler on condenser coil.

Chad provides a lot of detail on how to build the unit.  All of the parts are readily obtained locally or online.

The picture above shows the screen enclosure for the evaporator pads.  The pads fit between the two screens and are the same type of material as used in regular evaporative coolers.

The pump and all the valves fit in a 5 gallon bucket that sits next to the condenser coil unit.

An advantage of this method compared to just spraying water directly on the condenser coil is that mineral deposits do not build up on the coil.

All the details on building this system here...

Gary

New Home Page with "Web Walk"

Build-It-Solar has a new home page as of this morning....

About the only significant change is that the "New Content" area has been expanded to include a "Web Walk" section that gives some news items that might be of interest to people who are into renewable energy and building projects. The new page layout also gives a more complete overview of all the subject areas that Build-It-Solar covers.

I added the "News" section because I spend some time on most days looking at quite a few sites for new projects or project ideas, and I thought I might as well pass along other things of interest that I run across.
I plan to add a batch of "News" links every few days -- these sections are labeled "Web Walk" in the "New Projects" column on the home page.

If the new home page gives you any problems, or you have any suggestions, please let me know.

Gary

Prince Edward Island Passive Solar Bermed ICF Home on a Budget

This is Tracey's very nice home on Prince Edward Island, CA.   Its a passive solar home that uses earth berming on the winter wind sides, and uses ICF (Insulated Concrete Forms) for the walls.

The home has large south facing passive solar gain triple glazed windows for winter heat gain, along with roof overhangs that shade the house from unwanted summer heat gain.

South windows provide lots of solar gain to the heat storing floor.

The long east-west layout of the house and use of Solatubes to provide lighting in some areas makes for a very pleasant and bright interior.

The 1285 sqft floor plan.

Probably the most amazing thing is that the home was built on a very manageable budget.

Tracey provides lots of detail on the house including a book on the whole process of designing and building a  very efficient solar home within a budget.

All the details here...

Gary

Home Heat Loss Calculator -- Updates

Our Home Heat Loss Calculator gets used several hundred times a day, so I thought it would be good to make a few small updates.

The calculator lets you estimate the heat loss, yearly energy use, fuel cost, and greenhouse gas emissions that result from heating your house.  It estimates losses for ceilings, walls, windows, and floors and losses due to  air infiltration.  Its easy to use, and some examples are provided to get you started.

Probably its biggest value is giving you some idea where the major heat losses are in your home, which is the first step in identifying which areas will give the most bang-for-the-buck for improvements.  It also lets you try various improvements and see the resulting saving in dollars and CO2.

So, I cleaned up the forms, added a plot that shows at a glance how the heat loss from ceilings, walls, ... compare to each other, added some printing pagination, ...

The new plot

If you use the calculator now, be reassured that no algorithms have been harmed in this update -- it gives the same answers it always has.  The one small number change is that CO2 emissions for electric fuel were lowered from 2.2 lbs/KWH (typical of coal generators) to 1.5 lbs (average US generation).

Some parts of the calculator:
The inputs look like this -- basically define your climate, pick a heating fuel, and enter Rvalue and area for ceilings, walls, ...    Mercifully, there is only one page of inputs to fill in.

You just enter your numbers in the blue boxes.

The summary output looks like this -- yearly energy, cost, and CO2 for your house as well as coldest temperature hourly loss rate.

This is a simple calculator -- it uses the usual Loss = (Area)*(deltaT)/Rvalue for each component.  It uses Heating Degree Days for your climate to estimate yearly losses.  There are fancier calculators available that give more details and probably more accuracy, but this one is fast and easy to use and appears to do pretty well -- and its FREE :)

Give the Home Heat Loss Calculator a try ...

If you have any thoughts on improvements, let me know.

Gary

Using Your Lawn Sprinkling Water to Cool the House

This is a unique way of providing some free space cooling for your house.

Rick runs the water that he is using for lawn watering through a heat exchanger first and extracts some "coolth" from it before it goes out to the yard.

Rick's current test setup.

His current test setup uses a 20 by 20 inch water to air heat exchanger with a fan that blows air through the heat exchanger to cool it.  In this current test setup, it cools the airstream about 10F and provides about 5000 BTU/hr of cooling -- about a half ton of cooling.

The energy use is very low -- the COP appears to be about 29 (SEER 125!).

Side of HX with water connections.

All the details on lawn water for cooling here...

Thanks very much to Rick for sending this in.

Gary

Calling all Sunspace Owners

I think that home attached sunspaces may be the most cost effective and sensible approach to adding solar to your house -- attached sunspaces offer:

• Space heating for the house 
• Additional living space that can be very pleasant
• A place to grow plants
• A place to hang the laundry for solar drying
• A good place to locate a solar water heater

While direct gain to the house through south facing windows can be an effective solar heating scheme, the direct gain approach has the not so good feature of quite a bit of heat loss on cloudy days and at night through the large windows.  Sunspaces allow you to harvest the same heat through their large, south facing glazing, but the susnpace can be closed off from the house at night or on cloudy days to avoid the big glazing heat losss.

A nice sunspace

Compared to traditional active solar space heating (with collectors, tanks, pumps, ...) sunspaces can be better looking and more cost effective (when you consider all of the benefits).

Doug's sunspace

For space heating, low thermal mass sunspaces collect heat quite efficiently, and it is relatively easy to transfer this heat to the house.  A good writeup on the low thermal mass sunspace design...

While having a sunspace to hang laundry in bad winter weather may seem like a small thing, clothes dryers are are the largest single electricity use in many homes -- on average about 900 KWH a year!  Even more when you consider that the dryer is pulling in cold outside air as it vents its hot air outside.  The sunspace gives you a good, sheltered, efficient place to dry clothes.

Sunspaces make a good, protected enviroment to add a solar water heater to -- the water heater will be more efficient because it does not see outside temperatures, and may need less or no freeze protection.

I've got a section on Sunspaces, but it has few examples of good, attached sunspaces used as described above.

Sooooooooooooooo, I would REALLY like to hear from folks with sunspaces -- how well do they work for you?  What's good?  What's bad?  What do you consider good design features?  

A writeup on your sunspace with lots of pictures would make my whole week!

Nick's multi-story solar space heating sun space

Or, if you have some thoughts, experiences, or questions on sunspaces, how about passing them on in a Comment below.

Gary

Comparing the Performance of Two DIY Solar Water Heating Collectors -- CPVC vs Copper

Scott Davis has come up with an innovative and simple design for a solar water heating collector that uses CPVC pipes for the risers -- its easy to build and performs well.

Scott and his prototype CPVC collector.

The collector uses closely spaced CPVC riser pipes which are silicone bonded to a flat aluminum absorber sheet.    This makes for and easy and fast build.

I did a side by side performance test of Scott's design compared to the established DIY collector design that uses copper riser tubes spaced about 6 inches apart with thicker grooved aluminum fins to transfer heat into the riser tubes.  In this test, the CPVC design performed within 5% of the copper/alum collector, which I think is very good.

The side by side test of the two collectors.

There are a number of pluses and minus associated with the CPVC design compared to the copper/alum design -- things like cost, ease of build, performance, durability, and tolerance for stagnation temperatures are all important.  Which design works out best will depend on your situation -- I've tried to provide a little data on how the collectors compare in all these areas.  

I would be most interested in hearing your thoughts on the comparison and which collector you think would work out for your situation.

Full details on the performance and stagnation tests, construction, IR pictures, etc. for the two collectors...

Closer view of the test CPVC Collector.

IR image of the CPVC collector in operation

If you go ahead and build a CPVC collector, please let me know how it works out for you.

Gary

A New Heliostat for an Innovative New Application

There is an interesting new heliostat being offered for a low enough price to be of interest for building home systems.  The heliostat is made by Light Manufacturing Heliostats.

The heliostat has an area of 2.3 sm (25 sqft) .  The mirror is a stretched, reflectorized film to keep the cost and weight down.  Prices from about $1300.

Details on the Light Manufacturing Heliostat here....

The same company offers a unique application that uses their heliostats to provide heat for rotational molding of plastic parts (like large water tanks).  This solar thermal rotational molding system appears to be simple and cost effective, and (to me) represents some truly innovative thinking in bringing solar to a large industrial processes in a very energy efficient and cost effective way.

Diagram of solar thermal rotational molding system.

In the system, multiple heliostats focus their beams on the mold to provide the large amount of heat needed for the process.  The heliostats can support multiple molds by simply refocusing the heliostat beams on mold as needed.

The first video on this page provides a rundown on how the heliostat heated rotational molding setup works...



Heliostats can be put to many innovative uses -- I've assembled a few of them here...

Be sure to look at this one at the link above:
"ROME (Reuters) - A village in the Italian Alps is finally basking in winter sunlight thanks to a giant mirror installed on a mountain top to reflect the sun's rays into the main square."


Gary

Making Good Use of Mountain Pine Beetle Killed Trees

This is a good and interesting video from Peter Brown about a local Bozeman, MT company that is salvaging trees killed by the Mountain Pine Beetle.

Distinctive blue coloring of beetle killed pine.

It turns out that the fungus that the beetle infects the pines with leaves a blue stain in the wood  that makes for very attractive color patterns on the boards when sawed by an experienced sawyer.

The beetle killed wood's structural properties are unaffected by the beetle infection, and the wood can be used for a wide variety of purposes.  The blue staining gives it a distinctive look that has made it popular for furniture and doors.

A great example of making good use of local materials that would otherwise go to waste.

Neil Wilbert of Beetle Kill Boards with his portable saw mill.

Makes very nice furniture.

See the story  on Peter's Video Blog...



Gary