|
Passive Cooling Basics |
| The Energy Source Builder
newsletter
http://www.oikos.com/esb/51/passivecooling.html
|
 A
very good article that provides a simple method to allow you to
determine which passive cooling techniques are best for your
climate.This article is based on the book "Sun, Wind and
Light" (see below). |
| Be Cool -- Natural Systems to Beat
the Heat Preethi Burkholder with Claire Anderson
How to get articles from Home Power ... |
 Home
Power magazine article in issue 108 (Aug/Sept 2005)Very good
article on simple techniques to prevent heat gain and to provide
passive cooling.
It includes a method to determine which cooling techniques
will work best for your climate. |
Design a Home That Keeps You Cool,
Naturally,
William Hoffman, Fine Homebuilding August 2004
How to get articles from Fine Homebuilding ... |
 A
home that illustrates how a number of simple cooling techniques
that were combined in this house to avoid the need for air
conditioning in this south Florida climate. |
Passive Cooling -- Part 1 and 2
Cliff Mossberg
How to get articles from Home Power ... |
 Home
Power magazine article, issue 82 and 83Article on passive
design cooling techniques for hot humid climates with examples.
Many techniques covered. |
Lakeland, Florida --
Side by Side Test,
Florida Solar Energy CenterComparison of energy of a home
designed with many energy efficiency features to a same size
conventional construction home.
http://www.fsec.ucf.edu
|
 This
is a very detailed and carefully done study of two houses of the
same size in Lakeland Florida. One house was built
conventionally, and the other was equipped with a wide array of
features to reduce energy consumption, including: reflective
roof, internal duct system, thermal mass inside insulation, high
efficiency and properly sized AC, well designed overhangs, and
optimal windows.
The measured energy consumption was 70% less on the house with
low energy use features. A solar PV system offset and
additional 22%, bringing the net energy use to near zero.
The reports provide quite a bit of detail on the saving achieved
by each energy efficient design feature. |
| Arizona Solar Center -- Passive
Cooling
www.azsolarcenter.com/technology/pas-3.html
|
 A
good overview of passive cooling strategies. |
| Passive Cooling for Your North
Carolina Home North Carolina Solar Center
NC Passive Cooling Guide (pdf)
|
 Good
guide to passive cooling houses in the SE humid and warm
climates.From the NC Solar Center
|
| Landscaping for Energy Efficiency
South Carolina Energy Office
Landscaping for Energy Efficiency (pdf) |
 Booklet
on landscaping for energy efficiency. "Carefully positioned
trees can save up to 25% of household's energy consumption".
Several other energy saving "briefs" also available here. |
| Window Overhang Sizing Tool
Sustainable By Design Solar Tools
http://www.susdesign.com/design-tools.html |
 Properly
sized overhangs on south windows keep you cool in the summer and
collect sun in the winter.
|
| Designing Shading Overhangs with
Google SketchUp
http://www.sketchup.com/
Be sure to pick a location near you, or enter your
latitude/longitude -- otherwise, sun motions and shadows will
not be correct. |
 SketchUp
is a free 3D drawing tool from Google. In addition to be
exceptionally easy to use as a general purpose drawing tool, it
offers a shadows made by a built in sun. You can easily draw a
wall with a window and overhang, and play the sun over it for
various times of day and times of year.
It could also be used to layout your whole house (with trees and
sunspaces), and see how the sun plays over it.
VERY easy to learn. |
| Shading Guidelines
from Australia
www.greenhouse.gov.au/yourhome/technical/fs19.htm
|
 A
good set of guidelines on a variety of shading techniques.
Note that this is from Australia, so if you live in the northern
hemisphere, you need to reverse north and south in the write-up. |
| Sun, Wind and Light --
Architectural Design Strategies, 2nd Edition G. Z. Brown and
Mark DeKay |
Details on a large number of specific design strategies for
making effective use of the sun and wind, and natural lighting.
It includes quantitative analysis techniques for each strategy.
Intended for architects, but quite readable. Covers commercial
buildings as well as residences.
2001 400 pages |
Radiant Barriers,
SouthFace.org -- Energy Fact Sheet
www.southface.org Radiant Barrier Fact Sheet
|
 A
short but good Fact Sheet on radiant barriers from
SouthFace.org. |
Climate Consultant,
UCLA Energy Design Tools
http://www2.aud.ucla.edu/energy-design-tools/
Note: the psychrometric charts that this tool produces have
an overlay indicating which type of cooling techniques will work
well in your climate. A really nice tool. |
 Climate
Consultant is one of the UCLA Energy Design Tools.
It provides a variety of ways to visualize weather for a
specific location. Weather data files are available for
hundreds of locations. This is a brand new version, and is very
easy to use.
"It graphically displays climate data in either metric or
imperial units in dozens of ways useful to architects including
monthly bar charts, timetable charts, and psychrometric charts,
sun shading charts, and sun dial charts."
One of the most interesting charts is the
Psychrometric chart with overlays that show the design
strategies (e.g. passive solar, evaporative cooling, ..) will
work for the location in question.
|
Radiant Barrier Pilot
Project,
Florida Solar Energy Center,
D. Parker, J. Sherwin, and M. Anello
http://www.fsec.ucf.edu
|
 An
FSEC evaluation of the energy saving for radiant barriers.
Nine houses were monitored for attic temperatures and AC energy
use before and after installing a radiant barrier.
Bottom line was an about 10% reduction in AC energy costs, and a
somewhat improved comfort level. |
| Shading
Structures |
| Window (and house)
Shading How to keep cooler, save money, and be green all at
the same time
Window Shading Techniques
Gary |
 As
much as half the heat gain to your house can come from unshaded
windows. The sunny day heat gain from a hundred square feet
of east or west facing window is the equivalent of running your
furnace for several hours.
This is my 2 cents worth on several effective and (mostly)
inexpensive ways to shade your windows and cut down on house
overheating, high AC bills, and greenhouse gas emissions. |
| Sun Screens
http://sunbloxinc.com/
An article on this product:
www.energyrefuge.com/archives/solar_screens.htm
The screen material from Phifer:
http://www.phifer.com/sunprod.htm
And another -- there are lots of them:
http://www.ezsnapdirect.com/
Exterior window shades -- search for shades:
A similar
screening from Real goods |
 This
seems like a pretty good idea for reducing summer heat gain on
windows. The shades block up to 90% of sunlight, and mount in
vinyl frames (like bug screens). It looks like they would work
on a wide variety of windows, including ones that would be
difficult to handle with other shading techniques. They do the
shading on the outside, where its most effect.
It seems like a DIY version could be worked out. The Phifer
SunTex material is said to be available at some home centers.
Frames could probably be made from the same material that home
centers sell for making insect screens. |
| Exterior Roll Up See Through Shades
Details... |
 These
are exterior shades that roll down to to provide filtered shade,
but still allow a view out.We have these, and like them.
Details... |
Reflective barrier without the
shiny look
From Melissa's Cottage Rose Blog
http://thecottagerose.blogspot.com/...
|
 This
is basically a way to place a reflective (Reflectix) barrier
behind a solar screen. The advantage being that it blocks
essentially all the solar radiation while maintaining an
aesthetically pleasing look. It even provides a little more R
value to reduce conduction losses.There are also plans for an
external shade using a decorative layer over a Reflectix layer. |
| My Neighbor's Outstanding Trellis
All the details ... |
 My
neighbor has a terrific trellis with vines shading structure.
It makes for a great shady place to sit on hot sunny summer
days. In the winter with the leaves gone, it provides filtered
sun and some solar gain to the window area behind.
And, it provides beautiful fall color.
All the details ... |
| Alnet DIY Rollup Shade Cloth Shades
www.shade-cloth-diy.com/patio-enclosures/patio-enclosures.shtml
|
 Plans
for a simple rollup shade from shade cloth. |
| Trellis Cooling Pictures of the
trellis and other passive cooling features here:
www.inhabitat.com/2005/12/23/ecohouse-brazil/
|
 ECO
house in Rio de Janero uses an aluminum trellis to support
plants that will shade the house wall from from sun. |
| Living Wall System
http://www.eltlivingwalls.com
|
 In
addition to all the "green" benefits that these living walls
provide, it seems like they could be very useful for reducing
heat gain from walls that get a lot of sun.Lots of example
photos and some "hot to" information at this website. |
| Trellis Shading
DoItYourSelf.com Trellis Projects
|
 Some
sample projects/pictures that use an external trellis for
shading. This approach works well on East and West facing
windows where overhangs are not effective. |
| Shading Structures from 2007 Solar
Decathlon
A little more on the German entry:
www.inhabitat.com/...
Quite a few Solar Decathlon pictures from Inhabitat:
www.flickr.com/photos/inhabitat/1636531291/
|
 
German entry in the 2007 Solar Decathlon had a nice
porch/shading structure. Note the roof of porch is PV
modules. Note that this would even work on east and west
exposures.
 And,
this nice overhang on the Urbana-Champaign entry.
Click pictures to enlarge.
Pictures from
Inhabitat |
|
Some Trellis or Plant Screen Ideas ... |
These are some shading trellis or
plant screen ideas excerpted from a discussion on the
HomeEnergySolutions Yahoo discussion group
Thanks to the folks at HomeEnergySolutions for the good
ideas!! |
| The Green Shutter
www.inhabitat.com/2006/03/08/green-shutter/
|
 A
pretty neat design for a operable shutter with plants for sun
control. |
| Schiavello Vertical Garden From
Inhabitat:
http://www.inhabitat.com ...
|
 This
design seems as though it might work well for blocking unwanted
solar gain on windows (particularly on difficult to shade east
and west facing windows).
For this purpose, it would best be installed outside the window
on the ground or on a balcony.
Judging from the comments, it might be good to think about some
type of watering system. |
| Alnet DIY Awning Plans
www.shade-cloth-diy.com/awnings/awnings.shtml
www.shade-cloth-diy.com/awnings/retractable-awnings.shtml
|
 Plans
for a simple wood framed, shade cloth awning to provide window
shade and reduce heat gain.
 Retractable
version
|
| Alnet DIY Pergola Plans
www.shade-cloth-diy.com/pergolas/pergolas.shtml
|
 Plans
for a simple wood framed, shade cloth pergola from Alnet. |
| Alnet DIY Trellis
www.shade-cloth-diy.com/garden-designs/garden-designs.shtml
|
 Plans
for a simple wood framed, shade cloth trellis fro Alnet |
| Elegant Shade Structure Popular
Mechanics
www.popularmechanics.com
|
 Plans
for a very elegant shade structure. This could be used as a
standalone shade structure or adapted to shade a house window.
Very detailed plans. |
| Windsor Shade shelter California
Redwood Association
www.calredwood.org/ref/pdf/shelter.pdf
|
 Detailed
plans for a free standing shading structure.Could be used for
yard/deck shade, or to shade a window. |
| Rollup shade plans
From Charlie's Green House
www.CharliesGreenhouse.com
The Plans (pdf)
|
 Plans
for a simple rollup shade from Charlie's Greenhouse in Seattle. |
|
Shade Sails ,,, |
 Shade
Sails (or Solar Sails) are fabric membranes supported by fixed
anchors, and positioned to provide shade. They are laid out
and tensioned in such a way as to be very resistant to winds.
They can be used to shade decks, porches, play areas, windows,
...
They can be very nice looking indeed, and can handle some
difficult shading problems.
Example photos, and design information here ... |
| Reflective
Roofs |
Comparative Summer Attic Thermal
Performance of Six Roof Constructions,
Danny Parker and John Sherwin,
Florida Solar Energy Center, 1998
The full paper ...
|
 This
is an excellent paper that compares the attic temperatures for 6
different roof constructions.
Following the findings of this study can have a major
impact on your cooling costs.
If you don't have time to read the full paper, here is my
quick summary of the findings... |
| Cool Metal Roofing
www.wbdg.org/resources/coolmetalroofing.php
|
 Reflective
metal roofing can keep your house cooler and save on cooling
bills.
|
Measured Cooling Energy Savings
From
Reflective Roofing Systems In Florida:
Field And Laboratory Research Results,
Parker, Barkaszi, Chandra, and Beal
Florida Solar Energy Center
www.fsec.ucf.edu/en/publications/html/fsec-cr-1220-00/
Measured and Simulated Performance of Reflective Roofing
Systems in Residential Buildings,
Parker, Huang, Konopacki, Gartland, Sherwin, and Gu.
www.fsec.ucf.edu/en/publications/html/fsec-pf-331-98/
Measured Roofing Material Reflectivity's ...
A sampling of commercial sources ... |
 Actual
measurements of reduction in cooling energy for 8 homes in
Florida before and after coating the roof with a reflective
(white) coating.
Cooling energy savings averaged 20% just by going to a more
reflective roof.
The papers cover both roofing materials that are reflective as
well as coatings that can be applied on existing roofs.
The paper on Roofing Material Reflectivity is good and
surprising.
|
| "CoolWall" Paint
http://www.texcote.com/coolwall.php
ORNL Report... (pdf)
The flip side of this is that if you live in a cold climate,
painting your home with a dark shade will result in a saving in
heating energy. |
 "CoolWall"
paint reduces cooling costs by formulating the paint to be
reflective in the IR, but any color you like in the visible
spectrum. In other words, you can get the same sort of cooling
benefit that comes from painting your house white without having
to have a white house.
While many of the "save energy with paint" schemes are scams,
this one has been tested extensively by he ORNL (see links), and
does result in a 4 to 21% reduction in cooling energy.
It should not be used in cold climates in that the same high
reflectance in the IR that reduces cooling energy use increases
heating energy use. For example, in Richmond VA, the reduction
in summer cooling energy is more than offset by the increase in
winter heating energy.
In the ORNL testing, white paint outperforms the IR reflective
cool wall colors -- so, white paint is good for hot climates. |
| Cooling Towers
& Solar Chimneys |
| Ventilation Rates for Solar
Chimneys Energy and Buildings -- 32
www.ecaa.ntu.edu
|
 Paper
provides measured ventilation rates and room temperatures
achieved by four solar chimney designs. |
Passive Air Conditioning -- Low
Energy Cooling
Tom Elliot
www.thefarm.org/charities/i4at/lib2/aircool.htm
|
 Another
writeup on evaporative cooling towers with some design
information. |
| How to Stay Cool in the Hot Desert
(with less power) Charles Van Meter
http://millennium-ark.net
|
 A
passive cooling tower that uses wind and water evaporation for
cooling. No blowers -- only electric demand is a small water
pump.
Some design rules, and several years operating experience. |
|
Reflectors |
Reflector/Shades,
Steve Baer, Zomeworks Corporation
http://zomeworks.com/files/sunbenderTM/reflector-shades.pdf
|
 A
good paper by Steve Baer reviewing the use of seasonally
moveable reflectors to increase solar heat gain in the winter,
and reduce unwanted heat gain in the summer.
A nice mix of solar physics and practical how-to that Steve has
gained in the building of many of these types of reflector
systems over the years. |
Earth Tubes
Earth tubes are tubes buried in the ground
deep enough to take advantage of the more even year round
temperature at depth. Air from outside the house is run through
the earth tubes to heat or cool it before it is introduced into
the house. In the summer, the earth is cooler that the outside
air temperature and the air will be cooled as it goes through
the tubes, and the opposite in the winter. This is a simple,
energy efficient means of pre-heating or pre-cooling air, but
there are a number of things to consider -- so do your homework
carefully. |
| EERE -- Earth Tube Cooling A fact
sheet from the EERE site:
EERE on Earth Tubes |
The EERE on earth tube cooling.
They seem to be a bit "cool" to the idea -- and, I think they
make some good points. |
Performance of Single Pass
Earth-Tube Heat Exchanger: An Experimental Study,
Girja Sharan, Ratan JadhavData from an Earth Tube experiment:
Earth Tubes2003-01-07GirjaSharan.pdf
|
 An
interesting paper with some actual data on a real earth tube --
this might be helpful in designing your earth tube.
The data includes temperatures along the tube, airflows, fan
power, and COP. |
Passive Annual Heat Storage,
John Hait, 1983
http://www.earthshelters.com/
|
 This
book by John Hait is mostly about his Passive Annual Heat
Storage home design, but it does have a section on earth tubes
and how they are used on his houses.An interesting all around
book. |
| The Natural Home Building on
Earthtubing:
http://www.thenaturalhome.com/earthtube.htm
|
 Describes
the way in which earth tubes are used in their house design.
They also describe an earth tube system using water rather than
air in the pipes:
http://mb-soft.com/solar/alternwa.htmits hard for me to
tell whether they have actually built one of these or not. |
| Earth Tube Cooling -- Leopold
Legacy Center
Aldo Leopold Earth Tubes Paper
|
 A
large commercial application using earth tube cooling.Some
design numbers provided. |
Analysis, Design, and Prelimnary Testing of Solar chimney for
Residential Air-Conditioning Applications,
Gang Wang, Bing Chen, Mingsheng Liu, Joerg Henkel,
University of Nebraska, Lincoln |
 This
paper looks at the feasibility of using a solar chimney to drive
flow through an earth tube.
Both analysis and testing are provided. |
| REHAU Air - Ground Heat Exchangers
http://export.rehau.com/ ...
|
 This
company makes components for earth tube heating and cooling
systems.The downloadable pdf provides some useful information
for designing earth tube systems.
(thanks to Charles for finding this) |
|
Earth Tube Design Notes... Gary |
These are just some thoughts on
earth tube design based on nothing more than reading the
articles above. |
Efficient
Active Cooling -- Ventilation
In some climates, fan forced ventilation and a 24 hour cooling
strategy to reduce heat gain during the day, and make use of
cool night air can be very effective. |
| Whole House Fan for Cooling
Whole House Fan pdf (240K) |
 For
relatively dry climates with cool nights, whole house fans are
very effective in reducing or eliminating the need for
refrigerated AC. I have had a whole house fan in my last two
houses, and would not be without one! |
|
Whole House Fans Tech Sheet (pdf) PG&E
|
 Another
good guide on using and installing a whole house fan. |
| Energy Star Ceiling
Fans
www.energystar.gov
Getting the Most from Your Fan,
Chris Calwell and Noah Horowitz
Home Energy
Choosing and Installing a Ceiling Fan,
Fernando Pages Ruiz,
Fine Home Building Magazine
(very good how-to on installing ceiling fans)
|
 Ceiling
fans are an efficient cooling method for some climates and
conditions, especially when the use of a ceiling fan allows less
use of AC.
Energy Star ceiling fans use half as much energy as typical non
Energy Star fans.
Note the directory of approved fans, and the attention to making
any light that might be included with the fan an efficient one.
If you have several ceiling fans in your house, using energy
efficient fans could save you as much as 1000 KWH a year, so its
worth finding good ones and sizing them for the space.
Some thoughts on choosing an efficient ceiling fan ... |
| Ceiling fans with aerodynamically
designed blades
http://www.fanworks.com/vari-cyclone.htm
|
 Ceiling
fans with "Gossamer Wind" technology blades move about 40% more
air for the same power use.
Models are available that operate at 12 or 24V, and can be
operated direct PV or battery.
FSEC paper:
Performance and Applications of Gossamer Wind™ Solar Powered
Ceiling Fans |
Choosing and
Installing a Ceiling Fan,
Fernando Pages Ruiz, Fine Homebuilding, Nov 2001 issue 142
How to get articles from Fine Homebuilding .. |
 A
Fine Homebuilding article on choosing and installing a ceiling
fan. Lots of detail on mechanical installation for both new
construction and remodel, and detail on how to wire the fan. |
| Solar Attic Vent Fan
http://www.arttec.net/Solar/5-21-06/May21-06.html
|
 Guy
Marsden describes how to install a solar powered attic vent fan.
The fan lowers his attic temperature by abut 20 to 30F, which
reduces heat transfer through the ceiling.Adding attic
insulation and sealing plumbing and wiring penetrations through
the attic ceiling are other ways to lower heat transfer from the
attic to the living space. |
| Cooling Without AC
Details... |
 This
is the way we cool our house in SW Montana without using
conventional AC.
The strategy involves avoiding daytime heat gains, using cool
night air for thermal mass cooling, and evaporative cooling on a
few occasions. No AC.
Our cooling bills are less than $3 per month!
Details ... |
| Night Breeze Cooling System
www.davisenergy.com/technologies/nightbreeze.php
Home Energy Magazine article
Kicking the Air conditioner Habit (pdf)
|
 This
is sort of a highly sophisticated version of a whole house fan.
It eliminates or reduces the need for refrigerated air
conditioning by using cool night air to pre-cool the house for
the next hot day. |
| Fran's Use of
Subterranean Air to Defeat the Evil Air Conditioner
The whole story... |
 Fran
shows how he used cool air from his basement to defeat the evil
air conditioner.
A nice simple and effective system and a well written story ... |
Efficient
Active Cooling -- Evaporative Cooling
In some climates, evaporative (Swamp) coolers can be very
effective in both reducing energy bills and avoiding that
crumby, air-conditioned space feeling. |
| Evaporative Cooling
EERE Evaporative Cooler Basics...
EERE Modern Evaporative Coolers... (pdf)
CEC - picking/sizing evaporative coolers...
|
 Evaporative
coolers can be very effective and energy efficient in hot
climates that do not have high humidity. The newer indirect
models can even be used in climates with somewhat higher
humidity.
The constant circulation of air avoids the stuffy feel of
conventionally air conditioned spaces. |
| Mike the
Las Vegas Handyman Cuts Annual Power Bill By 60% With A Swamp
Cooler
http://www.pro-handyman.com/...
|
 This
is a good article that covers: 1) the kind of savings that can
result from a "swamp" cooler, 2) how to use a swamp cooler
optimally, and 3) some good tips on installing and maintaining
one.
Mike is in Las Vegas and reports a 60% on his annual electric
bill since using a swamp cooler for most of the cooling season
over that past couple years. |
| Cooling Without AC
Details... |
This
is the way we cool our house in SW Montana without using
conventional AC.
The strategy involves avoiding daytime heat gains, using cool
night air for thermal mass cooling, and evaporative cooling
on a few occasions. No AC.
Our cooling bills are less than $3 per month!
Details ... |
| Innovative Design
Eliminates Cooling Equipment Energy Source Builder #36,
December 1994.
http://www.oikos.com/esb/36/Inno_Des.html
|
 Article
describes a house in Davis, CA (103F summer design temperature)
with no refrigerated air conditioning system. The system uses
night time ventilation and thermal mass to provide cooling. An
evaporative cooler is operated at night to cool thermal mass. |
| New Evaporative Cooling Systems --
An Emerging Solution for Homes in Hot Dry Climates with Modest
Cooling Loads Southwest Energy Efficiency Project
Evap Cooler Report (pdf)
Evaporative Cooler Assessment from ToolBase:
http://www.toolbase.org
Two stage evaporative coolers:
www.homeenergy.org ... |
 Good
and detailed report on a new generation of evaporative coolers
that are more efficient, use less water, and require less
maintenance.These cooler in a relatively dry climate can save
90% compared to compressor driven conventional air conditioning! |
| PV Powered Evaporative Coolers
http://www.southwest-solar.com/
Some notes on a DIY one:
www.voltscommissar.net/competitive_edge.htm |
 These
evaporative coolers use low HP 12V fans that can be powered by
PV arrays. |
| Night Sky Roof Water Spray Cooling
system
www.pnl.gov/TechReview/whitecap/whitecap.html
EERE report
ORNL gov report
The first link above provides the most complete design
information, and describes three different roof spray system
designs.
While these papers seem to be aimed primarily at commercial
applications, residential applications may well be workable,
simple, and energy efficient.
Most beneficial for dry climates. |
 "This
innovation spray-cools water on the roof at night and applies
the cooled water to reduce subsequent cooling loads. On clear
nights, the sky is much colder than outdoor air, contributing to
high water cooling rates through a combination of evaporation
and sky radiation. Overnight, NightSky systems can typically
cool a large storage volume (preferably two gallons per square
foot of roof surface) to a final temperature as much as 12
degrees below the minimum night air temperature."Seems like a
very promising way to reduce the energy cost of cooling. The
5600 sqft prototype described in the first link achieved an EER
of 149. |
| Some Information on Designing and
Building Evaporative Pad Cooling System Ohio State University
Fact Sheet
http://ohioline.osu.edu/aex-fact/0127.html
|
 Information
for designing and making your own evaporative pad cooling
systems.I have seen systems of this type in greenhouses for
cooling. |
| Plans for Evaporative
Coolers
www.igcusa.com/Catalogs/Coolair%20Install.pdf
|
 Detailed
plans for making evaporative coolers.
Intended for greenhouses, but may be adaptable to other
situations. |
| Turbo Kool Evaporative
Cooler
http://www.turbokool.com/
Install Manual (pdf) |
 This
is a small 12 VDC evaporative cooler that is intended for RVs,
construction equipment, ... but might work well in any small
space.
The fan draws 4 amps, and the company says it will run directly
off a 60 watt solar panel. |
Efficient
Active Cooling -- More Ways (radiation
cooling, hydronic, roof sprinklers, misters, ...)
|
Theoretical Evaluation of the NightCool Nocturnal Radiation
Cooling Concept
Danny S. Parker
Florida Solar Energy Center (FSEC)New
report on the NightCool performance in test buildings:
Experimental Evaluation of the NightCool Nocturnal Radiation
Cooling Concept: Performance Assessment in Scale Test Buildings,
Danny S. Parker, John R. Sherwin
Florida Solar Energy Center (FSEC)
Daily performance of the test buildings,
http://infomonitors.com/ntc/
Note: I would tend to NightCool in the Experimental area,
so, if you go after this, bear in mind you may suffer the "being
a pioneer" learning curve. Please let us know how it comes
out. |
 This
is a simple, building integrated, cooling scheme that uses
nighttime radiation cooling from a metal roof to cool air in
the attic space. Attic air is then circulated into the living
area to provide cooling.
A simulation model is used to predict performance in various
climates -- the scheme works very well in dry areas, and fairly
well even in very difficult moist-warm climates (e.g. Florida).
One of the attractive features of this system is that the roof
is very conventional -- no massive ponds or moving insulation.
There is the potential in some climates to use the same metal
roofing/attic system for space heating in colder weather.
The new test report shows the results for two 10' by 16'
structures that were built to compare NightCool performance to
conventional AC in Florida. Very interesting and promising
results.
Tests of a a simple dehumidification system using desiccants
are now underway. |
| Florida Zero Energy
Test House Florida Solar Energy Center
The Report (pdf)
|
 A
home constructed in a very difficult cooling climate (central
Florida) to see if a combination of passive cooling techniques
to reduce heat gain, high efficiency AC, efficient appliances,
and a fairly large PV rig could produce near zero net energy
use. The home was largely successful in meeting these goals.
Net energy use was only about 18% of a control house built to
current codes.
Pretty good detail on how much energy each feature saved.
My 2 cents would be that the passive cooling, high efficiency
AC, and efficient appliances contributed 67% the of the savings,
while adding little to the cost of the house. The 4KW PV rig
contributed the other 33% of the savings, and probably cost
about $40,000. |
| Hydronic Cooling
Energy Source Builder, Issue 53
http://www.oikos.com/esb/53/hydroniccool.html
|
 An
article from the Energy Source Builder Newsletter on using
hydronic heating systems for cooling, including radiant floor
systems. |
Roof Sprinkler Cooling System,
John
Full Details ...
|
 Roof
sprinkler system lowers roof temperature and cooling bills by
keeping the roof cooler through water evaporation.
Added a description of another similar system 3/6/07 |
| Brown Machine Works -- Cool Rain
system
http://fp1.antelecom.net/bromac/7.html
|
 This
is a small business that offers a roof sprinkling system to cool
attic areas. They also sell parts to people who want to build
their own system.
They have a
detailed installation manual that should be helpful to those
building a system. |
| Mist Cooling
www.dripworksusa.com/...
|
 DripWorks.com
sells a misting kit that provides mist cooling for about 25
lineal feet (3 misters). Said to be easy to hook up.Mist
cooling can be very effective and comfortable if done well.
I've ordered the kit and will report on how it does.
It looks like water usage is about 3/4 gallon per hour per
mister outlet. |
|
Mist Cooling For Large Outdoor Areas |
 A
very simple mist cooler for large outdoor areas. Intended for
cows, but I don't think they will mind if you use their idea. |
| Cooling Tips |
| Water bed cooling |
 Randy
suggests that in hot climates sleeping directly on the water bed
bladder will be cooler.
Remove all the coverings except for a sheet or two, and let the
water conduct heat away from your body.
The temperature of the water in the bladder will be the average
of the last few days, and cooler than body temperature.
After more experience, Randy adds that during the cooler season,
you want more insulation (e.g. a blanket) between you and the
water bladder to keep it from getting to chilly. Its a mater of
adjusting the amount of insulation between you and the thermal
mass. |
Passive
Cooling Guides and Tools 
