Green Energy &Great HomesSPECIAL COLLECTION• Tiny Houses• 8 Easy Projects for Instant Energy Saving• Solar Heating Plan for Any Home
Cozy, Affordableand Inspiringtiny homesStart small, and you can enjoy mortgage-free living in a hand-built home.By Lloyd KahnIn 1973, we published our firstbook, Shelter, an oversized offspringof The Whole Earth Catalogthat featured 1,000 photos of buildingsaround the world.In those days, many people werelooking for ways to escape the conventionalsuit/job, bank/mortgage orrent/landlord approach to housing. InShelter, we encouraged people to usetheir hands to build living space, to becreative, to scale back, to start small.Like a lot of other ideas from the’60s, the concept of hand-built homesis popular once again. Tiny homes havebeen discovered not just by the public,but also by the media.The mortgage crisis has devastatedhousing in North America.Huge homes along with huge mortgageswere, in the end, unsustainable.Millions of people have had the rugpulled out from under them. Wagesare down, jobs are scarce and rents areinching ever higher.We’ve gone through a long period ofoverconsumption, of people living beyondtheir means, of houses too big andincomes too small. As we witness the endof a pie-in-the-sky housing boom andenter into an era of increasing costs forthat most basic of human needs — shelter— a grass-roots movement to scalethings back is taking root.Lloyd Kahn embodies the idea that we don’tquit playing because we get old, we getold because we stop playing. Here he is,skateboarding at 73.lew lewandowski; right: shelter publications (3)An Authentic Life, Doin’ What He LovesJust a few years shy of his 80th birthday, Lloyd Kahn is among the most enthusiastic, dedicated,hardworking and athletic — yes, athletic — guys I know. If they were to put a photonext to the definition of “authentic” in the dictionary, it could be a picture of Lloyd.When Lloyd came back from his stint in the Air Force in the late ’60s, he went to workas an insurance broker. But what he really wanted to do was surf and build houses, and heseems to have quickly picked up the habit of doing what he really wanted to do.His first building project had a living roof. Then he built a home in Big Sur from railroadtimbers and used lumber. He built geodesic domes for five years, before concluding thatthey don’t work well as homes. His present home in Bolinas, Calif., sits in the midst of alarge vegetable garden, includes a striking 30-foot-tall hexagonal tower and is covered withhand-split cedar shakes.Today he is one of the world’s leading voices in creative, environmentally sensitive,human-centered building practices. His early books were about domes. Later his passiongrew to encompass anything built with creativity and a conscience.A Lifetime Achievement Award. For more than 50 years, Lloyd has been sharing his passionabout building with the world. His company, Shelter Publications, has published hisseries of unique books that have inspired thousands of us to build our own homes. In recognitionof Lloyd’s exceptional contributions to wiser living, Mother Earth News presentedhim and his Shelter Publications team with a Lifetime Achievement Award (we’ve dubbed itthe “Mommy”).— Bryan Welch, Mother Earth News Publisher and Editorial Director
Beach-combed whalebonerafters on a tinyhouse in British Columbia.Off the grid, elegant,and on wheels.Texas: Two lofts and afull kitchen and bathin 12-by-28 feet.www.MotherEarthNews.com 41
I started gathering material for anew book, Tiny Homes: Simple Shelterin 2009 and have been amazed at theactivity in the small-house field. It’s athrill to see such enthusiasm, varietyand creativity in tiny buildings thesedays. Moreover, there’s a new audience:young people who are picking up onShelter ideas, 40 years later.Tiny Homes is our new survey ofscaled-down housing circa 2012.Written mostly by the builders, it’snot consistent in anything other thanthe size of the buildings. The styles ofwriting are diverse, as are the photos.The little homes run from elegant toshelter publications (5)funky, from hand-built to bought,from super-cheap to surprisingly expensive,from thoughtfully designed toseat-of-the-pants, just-go-ahead-anddo-itdreaming.The maximum-size building here is500 square feet — pretty small. But it’san alternative if you’re young or single;if you’ve lost your job or your home;if you want to get out of rent or mortgagepayments and cut back on stuff;or if, for any one of myriad reasons,you want to start over again in life.This alternative needn’t be permanent,but it may work for you rightnow. It needn’t be this small, but theideas here are certainly antidotes tothe overblown single-family housesof recent decades. It’s moving in thedirection of small.You can hire a builder or buy a prefabkit, or, if you can find the timeand can work with your hands, youcan do the building yourself. This willsave about 50 percent of your costs (laborand materials split about 50/50).Another economic fact: With a mortgage,over the years you pay back aboutBoth photos: Basicconstruction of thisCanadian cob housetook three weeks.42 Mother Earth News XXXX/XXXX XXXX
An owner-built, mortgagefreestraw bale home onthe Oregon coast.A tiny Texas house nodsto the Victorian era.A traditional cottage designedby Tumbleweed Tiny HouseCompany .www.MotherEarthNews.com 43
A Canadian float cabinwith its floating garden.shelter publications (3)A Montana cabin designedto resemble a fire tower.44 Mother Earth News XXXX/XXXX XXXX
A Special on Lloyd Kahn’s BooksTiny Homes, Simple Shelter is the fifth in a series of books from Lloyd Kahn’s publishinghouse, Shelter Publications. Through September 2013, we are offering a 25 percentdiscount on his latest works, HomeWork: Handbuilt Shelter (2004) and Buildersof the Pacific Coast (2008), as well as his newest book, showcased here, Tiny Homes(2012). To order, go to www.MotherEarthNews.com/Shopping and enter the promotioncode MMEPAD43 on the bottom of your order review page, or call 1-800-234-3368and give the promotion code to your customer service representative. (For an iBooksoptimizede-book version of Tiny Homes, go to www.SHLTR.net/th-ibooks.)twice what you borrowed.Here we are in the midst of an electronicrevolution, and you still need yourhands to build a home. Your computerisn’t going to do it for you. It’s comfortingthat not all of the skills of the pasthave been superseded.If you embark on such an adventure,my advice now is the same as it was40 years ago: Start small. Kitchen andbathroom back-to-back for efficientplumbing. Hot water from solar panelsin summer; water-heater coil in thewoodstove for winter. This is your core.You can live in it while you add on.In Shelter, we wrote that self-sufficiencywas a direction, not an attainablegoal. The idea was to do as much foryourself as possible. Maybe not plowingfields with horses or making your ownshoes, but doing something within thecontext of your life: remodeling a house,creating a studio, building a table or bed,or fitting in things such as a productivegarden, chickens, homemade bread, orlettuce in pots on the windowsill. It’s atightrope act, finding the right balancebetween work for others and work foryourself, between creating things withyour own hands and buying things fromothers — just like finding the balancebetween sitting at a computer and physicalactivity. These are complex times.Do I live in a tiny home? Well, no. Butit started out tiny.When I began building, we slept ina bedroom that was barely big enoughfor the bed. We cooked on a Colemancamping stove in an outdoor kitchen(on a deck). Our home got bigger, but itstarted small.Lloyd Kahn has been the godfatherof hand-built shelter since 1970 andcontinues to lead the way. He liveswith his wife, Lesley, on a half-acrehomestead in northern California.A covered deck provides additionalliving space in this Washington cabin.www.MotherEarthNews.com 45
8EasyProjectsforInstantEnergySavingsWith these inexpensive ideas you can reduce yourcarbon footprint and slash your energy bills.Spend $400 once to save $900 a year!by Gary ReysaReducing your home energy use is the best of winwindeals — not only does it reduce your carbonfootprint, it also saves you big bucks on your energybills. That’s especially exciting when you considerthat many home energy improvements are fast, easy and inexpensive.Often, the savings from an individual project are small,but when you start putting them together they add up quickly.My family set a goal of cutting our total energy use, energycosts and greenhouse gas emissions in half, and we were able tomeet that goal with the help of these simple home projects. Wefound these reductions in our energy use easy to accomplishwithout making any significant lifestyle changes.Here are the details: We cut our total energy use from 93,000kilowatt hours (kWh) per year to 38,000 kWh per year. Thisis saving us $4,500 per year in energy costs, and has reducedour carbon dioxide (CO₂) emissions by 17 tons! Our rate ofreturn on the money we invested in this program is more than50 percent — tax free.Altogether, we took on 22 different projects, including twosolar heating efforts that have already appeared in MotherEarth News. You can find details about all the projectswe’ve done at our home in Montana on my website, www.BuildItS olar.com. But those I’ll explain in the following pagesare the fast, simple ones. These eight easy home improvementprojects cost us about $400 and will save us at least $9,000 overthe next 10 years!Prioritizing the ProjectsWhen you start looking at any group of energy saving projects,you’ll likely find a huge difference in the bang for thebuck. In our case, it was the simple things — such as controllingthe amount of power that our computers use or basic
The Top Eight ProjectsInitialCostSavingsper YearEnergyReductionper YearCO ² Reductionper YearPersonal Computer Power Management $20 $178 1,780 kWh 3,560 lbsInstall Compact Fluorescent Light Bulbs $50 $117 1,170 kWh 2,340 lbsSeal and Insulate Heating Ducts $20 $75 940 kWh 480 lbsReduce Infiltration Losses From House (Seal Leaks) $50 $156 1,980 kWh 1,010 lbsVent Dryer to Inside During Winter $5 $63 630 kWh 286 lbsInsulate Windows With Bubble Wrap $38 $75 960 kWh 490 lbsEliminate Phantom Electrical Loads $70 $57 570 kWh 1,140 lbsUse an Electric Mattress Pad $125 $186 2,320 kWh 1,150 lbsTotals $378 $907 10,350 kWh 10,456 lbsinsulating projects — that hadespecially good paybacks. On theother end of the spectrum, thesolar photovoltaic project we intendto do in the future will costas much as all 22 of our otherprojects put together, yet will onlyaccount for 2.5 percent of the totalenergy reduction!Why was the total payback onour projects so good? The keys toour success were:• We did quite a bit of homeworkbefore we got started. We evaluatedeach project for what itwould cost and what it wouldsave, and threw out the onesthat wouldn’t pay well.• Some projects cost almost nothing,but have big savings — youcan see on the chart above thatseveral paid for themselves manytimes over within the first year.These tend to bring up the averagereturn of the overall effort.• We are do-it-yourselfers — this can make a huge difference inthe costs involved in some projects.• Another bonus is that some of our energy improvementsqualified for rebates or tax credits that further increased themoney we saved.Electricity andGreenhouse GasThere’s another reason to dothese projects. Cutting down onelectricity use is very effective inreducing greenhouse gas emissions.Unfortunately, in the UnitedStates, most of our electricity comesfrom inefficient coal plants. Coal isa high carbon fuel, and comparedto other energy sources, coal-firedplants produce a lot of carbon dioxiderelative to the amount of energythey produce.If we’re concerned about climatechange, we should be shutting downcoal plants. Instead we are on courseto build more of them — manymore. To me, this argues for doingan especially aggressive job of trimmingyour electricity use. If youwant to reduce your contributionto greenhouse gases, most peoplewill be able to find many hundredsof kilowatt hours that can be savedeasily and cheaply with minimallifestyle change. We get our electricityfrom a coal-fired plant, so all theprojects we did significantly reduced the amount of greenhousegas we produce. Notice that the projects that save electricity reducegreenhouse gases by about 2 pounds of carbon dioxide per 1 kWhof energy saved. For example, putting our two home computers ona power diet saved nearly 1,800 kWh per year and 3,500 poundsof greenhouse gas!istockphoto/mike clarke
1Personal ComputerPower ManagementComputers and all their related equipment, such as printersand wireless routers, consume a lot of power. Together,our two computers and related equipment used 270 watts wheneverthey were switched on, but we found there was an easyway to reduce this amount. We put all the computerjunk on a power strip, so that at night we couldturn off everything with one flip of the powerstrip switch. We also started using the energysaving settings on our computers. Duringthe day, we have the computers set to hibernateif they are inactive for 15 minutesso that the computer stops consumingpower. This saves a total of 1,780 kWhper year, 3,560 pounds of greenhousegas, and $178 per year! Recently, we alsostarted using a new gadget called the MiniPower Minder that automatically powersdown all our peripherals when the computergoes into hibernate. At only $15, it’s a bargain.Energy savings/year 1,779 kWhInitial cost $20DIY labor 1 hourCO ² reduction 3,557 pounds$s saved/year $178Energy source Electricity1st year return 890 percent10 year savings $2,8342Install Compact FluorescentLight Bulbs Throughout the HouseWe decided to replace all of our existing incandescentlights with compact fluorescent light bulbs (CFLs). Thereis a much larger variety of CFLs out there now than there werejust a few years ago. You can find them for most situations, includingfor lights with dimmer switches and decorative bulbs.We spent about $50 on new light bulbs, after you factor in somerebates from our utility. Many utilities offer rebates on CFLs, socheck to see whether yours does.Energy savings/year 1,168 kWhInitial cost $50DIY labor 2 hoursCO ² reduction 2,336 pounds$s saved/year $117Energy source Electricity1st year return 234 percent10 year savings $1,861(All calculations on 10-year savings are based on an estimated10 percent increase per year in the cost of energy.)3Seal and Insulate Heating DuctsWe sealed the exposed heating duct joints with ductmastic and insulated all the ducts that were not alreadyinsulated in the attic and the crawl space. That wasn’tmany in my case, but it’s still worth doing.The cost for sealing ducts is minimal — a can ofduct mastic costs about $5. The cost for insulatingducts is also low — about 25 centsper linear foot of typical ducting. I figuredit cost about $20 total, becausemost of my ducts werealready insulated.Unless you pay to have theducts tested professionally beforeand after you insulate them, estimatingthe savings is a guess atbest. Good sources say that ductlosses are typically high — 15 percentto 30 percent on average ofyour heated air from the furnace islost through cracks and openings at theduct joints. But in general, you can’t get ata lot of the ducting that runs through walls onan existing house. I focused my efforts on the ones Icould get to in the attic, crawl space and basement.I estimated the fuel savings for my house at a conservative3 percent. However, a man I know who has sealed many ductsystems and then measured them says he can get measuredleakages down to 5 percent. In other words, this project madeIt’s easy and inexpensive to add insulation around ductwork, and doing socould lead to big energy savings.gary reysa; power button: istockphoto/phil earley; cfl: istockphoto/eric delmar
sense for my home, but it might save you much more than thefigures listed below, depending on how well sealed your homealready is. Just put it on your list of “must do” things. It may ormay not bring you huge savings, but it’s easy and cheap to do.Energy savings/year 940 kWhInitial cost $20DIY labor 4 hoursCO ² reduction 479 pounds$s saved/year $75Energy source Propane1st year return 375 percent10 year savings $1,1954Reduce Infiltration Losses(Seal Your Home’s Air Leaks)Most homes have many places where air leaks in andout, including around doors and windows, but especiallyaround plumbing, wiring and light fixtures that penetrateinto the attic or crawl space. We decided to caulk around all thewindows, and seal wiring and plumbing penetrations from theliving space to the attic. For this project, I bought a few tubesof caulking and some polyurethane foam in cans, which cost atotal of about $50.You can find the obvious air leaks yourself because you’ll feelthe drafts, but you might be surprised at some of the placesyour home is losing heat. The best way to find these spots isthrough a professional inspection, including a blower doortest. If your utility offers this service, you should definitely takeadvantage of it. Then take every opportunity during the test toidentify infiltration locations, so you can fix them later.Again, the savings for this project are hard to estimate unlessyou’re willing to pay for a professional test. I guessed thatinfiltration was cut down by 0.1 ACH (Air Change per Hour).This would amount to about 10 percent air leak reduction ona typical house having a 1.0 ACH, or 20 percent on a well builtand tight new house.I estimate this reduction would be equal to 6,100,000 Btu/year, which is equivalent to 73 gallons of propane burned in a90 percent efficient furnace, or 1,980 kWh. Again, the cost isso low and the potential savings are so high that this project isa must-do.Energy savings/year 1,980 kWhInitial cost $50DIY labor 8 hoursCO ² reduction 1,009 pounds$s saved/year $156Energy source Propane1st year return 312 percent10 year savings $2,485If you have an electric (not gas) dryer, you can make this homemade filterusing pantyhose. The filter allows you to vent the dryer indoors ratherthan outdoors, which takes advantage of the waste heat.5Vent Dryer Inside During WinterWe have started to route the clothes dryer heat vent tothe inside of the house in the winter. We live in a verydry climate, so the added moisture is a benefit, not aproblem. There are two major advantages of venting inside.First, you recover the heat that was added to dry the clothes(about 2.2 kWh per load). Second, you avoid bringing in coldoutside air to make up for the air that the dryer is pushing outside.To vent to the inside, you need to have a dry climate, anelectric (not gas) dryer, and a way to catch the lint in the dryerexit stream. The cost of this project was $20 for some tubingand a lint filter.Caution: Gas dryers should never be vented inside, because toxiccombustion products are in the vented air. Electric dryers shouldonly be vented inside if your climate is dry — be alert for anymoisture problems.Energy savings/year 630 kWhInitial cost $5 to $20DIY labor 2 hoursCO ² reduction 286 pounds$s saved/year $63Energy source Propane1st year return 315 percent10 year savings $1,002gary reysa; caulk: istockphoto/carlin photo
New energy-efficient windows are an expensive investment, but there aresimple fixes that will make your existing windows more efficient. One ofthe fastest and cheapest is to cover them with bubble wrap.6Insulate Windows WithBubble WrapThis is a neat idea that comes from the greenhouse crowd.You can insulate windows using bubble wrap packing materialby spraying a water mist on the window, and then applyingbubble wrap. The bubble wrap will usually stay in place for thefull season with one spray. The bubble wrap distorts the view, butdoes allow good daylight to come through. It’s a good option forwindows that you don’t need a view out of.This is very cost effective — payback is usually less than oneheating season. At the end of winter, you can just pull the bubblewrap off, roll it up and save it for next year. If you are going to use alot of bubble wrap, it’s worth finding a dealer in packing materialsto buy it from (or a greenhouse supply place). You can get bubblewrap from shipping companies such as UPS, but their prices aremuch higher.My cost was 27 cents per square foot for 141 square feet, for atotal of $38. This is something you can do in a couple hours, anduse until you decide on a longer term solution — if ever.Energy savings/year 955 kWhInitial cost $38DIY labor 1 hourCO ² reduction 487 pounds$s Saved/year $75Energy source Propane1st year return 197 percent10 year savings $1,195gary reysa (2); penny: istockphoto/skip odonnell7Eliminate Phantom Electrical LoadsI suggest we lobby our representatives in Congress to haveall electrical devices labeled with the amount of power theyuse when they are switched “off.” These “phantom loads”are relatively small, but they add up to considerable wasted electricity.For now, the easiest way to find out how much power yourappliances and gadgets consume even when they’re “off” is withan inexpensive meter, such as the Kill-A-Watt. You plug the Kill-A-Watt into the wall, and then plug the device into the Kill-A-Watt.The meter measures power use and keeps totals for the time it’splugged in. Other brands work similarly — WattsUp is another.In my home, all the phantom loads added up to a total of about80 watts of power. That’s 700 kWh per year! With power strips,you can completely turn off everything plugged into them by turningoff the power strip. I used power strips to eliminate 20 of the80 watts, and that is what I show below. The remaining 60 watts ismy fancy Dish HDTV receiver that always uses 60 watts. Turningit off has no effect on its power consumption whatsoever! The onlycost of this project was a couple of power strips — about $20. Ispent another $50 upgrading my satellite receiver. It still consumespower when it’s off, but only about 15 watts instead of 60.Energy savings/year 569 kWhInitial cost $70DIY labor 4 hoursCO ² reduction 1,137 pounds$s Saved/year $57Energy source Electricity1st year return 81 percent10 year savings $907Most appliances use energy even when they are turned off. But byplugging multiple cords into power strips, you can turn them completelyoff with one flip of the power strip switch.
8Use Electric Mattress PadsUnlike electric blankets, the power consumption for mattresspad heaters is very low (about 0.15 kWh per night).By using these electric mattress pads to heat the bed, we’reable to keep the temperature of the rest of the house much lowerand still be comfortable. We have two furnaces in the house, butsince putting in the electric mattress pad heaters, we have been ableto turn off the furnace that heats the bedrooms. The savings inpropane is considerable, and the comfort is outstanding.Others have reported being able to do the same thing with gooddown comforters and the like, but we’ve tried that and it doesn’twork nearly as well for me. The mattress pad heaters vary in price,but ours was $125. The dollar savings were $186 per year.Energy savings/year 2,320 kWhInitial cost $125DIY labor 0 hoursCO ² reduction 1,150 pounds$s Saved/year $186Energy source Propane1st year return 148 percent10 year savings $2,963Gary Reysa is an accomplished do-it-yourselfer who hastackled dozens of home energy projects, large and small.This article is adapted from material on his website, www.BuildItSolar.com, where you can find many more projects.If you keep your bed warm with an electric mattress pad, you can saveenergy by turning down the thermostat at night.gary reysa; money: istockphoto/skip odonnellThe Next Eight Home Energy ProjectsReady to tackle more home improvement projects? The eight projects featured in this article are those that yield big savings the fastest,but the eight projects listed below also yield large savings over time. Here are the costs and savings that Gary Reysa found when tryingthem in his home. You can read more about them on his website, www.BuildItSolar.com.ProjectInitialCostSavingsper YearEnergyReductionper YearCO ² Reductionper YearAdd More Attic Insulation $256 $126 1,593 kWh 812 lbsAdd More Crawl Space Insulation $210 $86 1,094 kWh 558 lbsBuy a New, Efficient Clothes Washer $400 $35 350 kWh 700 lbsBuy a New, Efficient Refrigerator $800 $72 720 kWh 1,440 lbsInstall Storm Windows $450 $220 2,700 kWh 1,100 lbsInstall a Storm Door $200 $17 216 kWh 100 lbsInstall Thermal Shades $1,086 $258 3,159 kWh 1,525 lbsRemember to Turn Off Everything! $0 $44 438 kWh 876 lbsTotals $3,402 $858 10,270 kWh 7,111 lbs
Plan Your Own ProjectsWhen we started our series of energy improvement projects, ourgoal was to cut our power usage and greenhouse gas emissionsin half. We’re amazed at how easy it was and how muchmoney we saved. But houses and living situations differ, soif you’d like to tackle your own half plan, you may needto choose a different list of projects. Here are some tipsfor getting started.Make a full list of projects to1 reduce your energy use.Build a big list of candidates to choose from.These are some helpful resources:EERE Consumer Tips: http://www1.eere.energy.gov/consumer/tips/m/index.htmlHome Energy Saver: hes.lbl.govEnergy Star: www.EnergyStar.govEEBA: http://eeba.org/Rocky Mountain Institute: www.rmi.orgDon’t do projects that aren’t2 feasible for your residence orsituation.Some projects will be impossible for your home orsituation — throw these out. You might want to put someprojects that look like a big stretch on a separate list to belooked at later.Evaluate each project — estimate the3 cost, energy savings and greenhousegas reduction.For each project on your list, see if you can come up with atleast a rough idea of what it would cost and what kind of energysavings it would achieve. In the project descriptions for everythingwe did, I’ve included how we estimated the cost, energy savingsand greenhouse gas reduction.Make a master list of projects that you4 intend to do over time.Using the results of your evaluations from Step 3, weed out theprojects that don’t seem worth it. This should leave you with agood list of projects that make sense for your situation, economicsand the planet.Sequence the projects. Put them in5 the order you want to do them.All things being equal, you might as well do the projects thatsave the most first. But there are other factors to consider, such asthe fact that some projects may interfere with others if done tooearly. For example, it’s hard to seal up the electrical and plumbingpenetrations from the living space into the attic if you haveto wade through the 18 inches of loose-fill insulation that youjust added. Also, your budget may require putting off some of thepricey projects until later, or you might just be more interested insome projects than others.Do them! Have fun and keep track of6 your progress. Be proud of the results.Keep your utility bills so you can see what progress you are making.The bills will also be helpful if you sell the house to show itsimproved energy efficiency.Here are a few other resources to keep in mind. If you are doingthe insulating and weatherizing projects yourself, then Insulateand Weatherize by Bruce Harley is well worth the price. There arealso some helpful how-to guides and plans mixed into these pages:www.BuildItSolar.com/Projects/Conservation/conservation.htm andwww.BuildItsSlar.com/Projects/Projects.htm.— Gary Reysaistockphoto/duncan walker
SolarHeating PlanBy Gary Reysafor Any HomeSlash your home heating bills with this exciting solar project.If you can build a deck, you can build this super system!It’s time to take advantage of solar heatto reduce your dependence on fossilfuels and lower your heating bills. Thissimple, yet effective, system can be utilizedin almost any home. Because the solar collectorsand the heat storage tank for the systemare built into a small new outbuilding,you don’t need to completely remodel yourhome to use solar heat. On sunny days (oreven partly sunny days) the collectors addheat to the storage tank. When the houseneeds heat, hot water from the storage tankis transferred to the house via an undergroundpipe into a radiant floor heatingsystem. The new building that houses ourcollectors is a storage shed, but yours couldbe a studio, playhouse or workshop.Advantages of this approach• The collectors are mounted atground level, where they are easy tobuild and maintain.• The collectors can be oriented andtilted for maximum solar collection.• The collectors and the building canshare a structure in such a way thatthe material costs and time to buildare reduced for both the collectorsand the shed.• The collectors look good integratedwith the shed (see the shed at far rightin the photo below).• You don’t have to find a space for alarge thermal storage tank in the house.• The steeply tilted or vertical collectorslocated close to the ground benefitfrom light reflected off the ground,particularly when the ground is snowcovered. And, vertical or near verticalcollectors are less prone to overheatingin the summer.ConsiderationsThere are many ways to build this system,but remember these design guidelinesto ensure that your system works well:• The collectors should face within 30degrees of true south and should notbe shaded by trees or structures duringthe three hours before and after solarnoon. Be sure to check carefully forany obstructions that would shade thecollectors.• To minimize heat loss from the pipesthat carry water to the house, the collectorsshould be as close to the houseas possible. The pipes should be wellinsulated and the trench should bedeep enough that the pipes are belowthe frost line for your area.• The thermal storage water tank mustgary reysa
e well insulated. This requires carefulinsulation and careful sealing of thetank lid.The system that distributes the heatwithin the house should be able to usewater that is as low in temperature as possible.Lower temperature water for heatingwill allow the solar collectors to operatemore efficiently and collect more heat.We added a radiant floor heating systemto distribute the solar heat throughoutour home. This radiant floor can makeuse of water as cool as 85 degrees to heatthe floors.Our system is designed to be as simpleas possible. It uses a design in which waterdrains back from the collectors intothe storage tank for freeze protection.Because it uses plain water and the systemis vented to the atmosphere, thereis no need for expansion tanks, pressurerelief valves, vacuum breakers, antifreezeor heat exchangers. The collector loopplumbing consists of a few feet of pipeand a circulation pump — that’s all. Thissimplicity reduces the cost and labor toput the system together, and the absenceof heat exchangers increases efficiency.The total amount of work does add up,so be sure to allocate sufficient time — it’snot a one weekend project. But, it’s notrocket science. If you can build a deck,you can build this system.Designing the SystemThe shed can be almost any design. Wechose a modified gambrel roof to matchthe style of our existing garage and to providea loft with good storage room. Theonly requirements are that the shed has asouth wall or steep south roof extending toground level and is large enough to providethe collector area that you want.To make it easier to integrate the collectorswith the south wall of the shed, choosethe south wall width, height and stud spacingto match the collectors. This may resultin slightly unconventional dimensions. Thebest plan is to start from the size of the collectorabsorber plates and glazing panels,and work from there.We chose the collector bay frame widthspacing of 48 1 ⁄4 inches so that standard48-inch glazing panels could be mounteddirectly on the collector frames with nocutting. The quarter inch allows for glazingpanel expansion.The absorber plates are the heart of thecollector, and much of the collector’s performancedepends on the absorber. The platesalso are fairly difficult and time consumingto make because they consist of a series ofcopper tubing soldered to copper sheeting.The copper tubes are connected by manifolds.The absorber plates can be purchasedwith a selective finish that reduces heat loss,making them more efficient. We decided tobuy pre-made StarFire collector absorberplates, then make the rest of the collectorframe and covering from standard lumberand greenhouse supply parts. We usedtwin-wall polycarbonate glazing, which isslightly more efficient than single wall glazingand is easy to work with.In order for the collectors to drain backto the tank when the pump shuts off, thecollectors must slope down toward thetank. This requires that the entire bank ofcollectors be sloped toward one end with aslope of at least one-eighth inch per foot.The plumbing also must be sloped, and nolines should be less than three-quarter inchdiameter. We used 1-inch copper pipe.Build The Shed & CollectorThe south wall of our shed is conventional2-by-6 stud construction with halfinchplywood sheathing. There is no sidingon the south side, and the sheathing alsoserves as the back wall of the collector. Thecollector framework is laid out right overthe south wall sheathing. It is best to layout the full collector frame on a flat surfaceso you can make sure everything fits andgang cut the notches in the frame for theabsorber manifolds and the horizontal glaz-Gary Reysa’s home inthe foothills of southwestMontana. Heat collected inthe shed (right) is transferredto the house (left) viaunderground water pipes.The collectors on the garage(middle) heat the garage withsolar-heated air.
enewableenergying supports. When cutting the manifoldsupport notches in the framework, be sureto allow for the fact that the absorber manifoldsmust slope and the lowest corner ofthe absorber panels must be several inchesabove the tank water level for drainage.Install the collector frame on thesouth wall sheathing. Use lag bolts withthe heads in counter bores to makethem flush with the front of theframe. Caulk all the outsideedges to prevent airleaks. The front surface ofthe frame is the surface onwhich the glazing panelswill be mounted, so makesure it’s smooth.Install polyisocyanurateinsulation in each collectorbay. Nail it to the sheathing with largehead nails. Do not use polystyrene insulationinside the collector — it will melt.Drill a half-inch drain hole in the bottomboard of each collector bay so that anywater that might get in can escape.Trim the ends of the absorber manifoldpipes so that they will fit togetherwhen installed in the frame, then placethe absorber plates into the notches in theframe. We soldered the manifolds togetherusing ordinary copper solder couplings.The supply line from the tank pumpis hooked to the bottom manifold at thelower end. The return line is hooked tothe top manifold at the higher end. Theremaining open ends of each manifold arecapped. Test the manifold for leaks.We included vents in each collectorbay to reduce the likelihood of the collectoroverheating when no water is flowingthrough it. The vents consist of high andlow openings in the back wall of each collectorbay. Air from the shed enters thelower vent, flows through the collectorand exits the upper vent. This flow of airprovides cooling for the collector. The upperopenings have doors to control airflow.Install the horizontal glazing supports inthe previously cut notches. These are locatedjust behind the glazing panels to supportthem and prevent them from buckling. Weused electrical metallic tubing (EMT) conduitfor the supports.Solar CollectorsWater TankInstall the glazing panels. We used4-by-12-foot twin-wall polycarbonateglazing panels and secured them with1-by-2-inch vertical strips screwed to thecollector frame. These cap strips are rippedfrom composite deck boards, which arelikely to last longer than ordinary woodstrips. We used stainless steel screws toprevent rust stains. No caulk or glazingtape was used between the glazing panelsand the collector frame — which hasworked fine, with no leaks — and it makesremoving glazing panels much easier.Twin Wall PolycarbonateRadiant FlooringCap Strip2x4 Frame Stud2x6 Shed Stud (24” O.C.)Collector Cross-SectionTop ViewTHE Storage TankThe tank is large enough to hold aboutone sunny day’s worth of collected sunshine.On a sunny day, thetank can hold enough energy toheat the house through the night andpart of the next day if it’s cloudy. A generalrule of thumb is to have about 1 1 ⁄2 to 2gallons of water storage per square footof collector.The waterline of the tank must be severalinches below the lower manifold ofthe collectors in order to allow the collectorsto fully drain back into the tank. Inour case, the 3-foot-high tank is sunk intothe ground about 2 feet so the collectorscould be mounted just over a foot abovethe bottom of the south wall.We chose to build a tank that usesplywood walls lined with an ethylene propylenediene monomer (EPDM) rubbermembrane (pond liner). The tank bottomand walls are three-quarter-inch exteriorplywood. The plywood is supported by a2-by-4 frame around the base of the wallsand a second 2-by-4 frame around theAbsorber Plate Risers1” Polyisocyanurate Insulation1/2” SheathingTrenchWater Line OUTWater Line INlen churchill (2)
enewableenergytop of the walls. A single 2-by-4 verticalstiffener is used in the center of thelong walls. A beveled vertical 2-by-3 isused in each corner of the tank to tiethe end walls and side walls together. Ametal tension tie extends across the topof the tank at the midpoint of the longwalls and ties the top of the long wallstogether. This tension tie is necessaryto keep the long walls of the tank fromfailing due to outward water pressure.The tank construction is important;it will be holding about 4,000 poundsof water! All joints should be carefullyglued and screwed together. The tankmust sit on a level and solid surface. Weplaced the tank on about 3 inches ofwashed gravel, which had been leveledand tamped.When the tank plywood shell is completed,cut a piece of EPDM pond liningmaterial large enough to line the entire tankwith no seams. Lay the liner over the top ofthe tank and carefully work it down intothe tank. After the liner touches the bottomof the tank, take off your shoes and workfrom inside the tank. Continue workingthe liner into the tank until it is against thewalls. Work all the extra material in eachcorner into a single, neat fold. Then securethe liner to the top frame with siliconeThe water storage tank is built from plywoodand pond liner material.caulk held in place with some staples andtrim off the excess.The tank lid is made from two layersof 2-inch-thick rigid foam board glued toa sheet of hard board. The bottom is coveredwith a layer of EPDM. The lid mustbe firmly held to the tank to prevent watervapor from escaping — we used lag screws.Be sure to mount the pump and controllerwhere they are protected from lowtemperatures. We did this by positioningboth in a compartment close to the storagetank, with most of the insulationdetouring around the outside of it sothe compartment is kept warm by heatfrom the tank.Most of the pipes coming into thetank go over the top edge then downinto the tank. This eliminates penetratingthe EPDM liner and reduces the potentialfor leaks. The exception to this isthe pump inlet connection, which doespenetrate the tank wall. This is necessarybecause the pump must be mountedbelow the tank waterline to retain itsprime. Use a high-quality bulkheadfitting for the connection through thetank lining.Heat Transfer TrenchThe trench for the transfer pipesshould extend below the frost line, andinsulation of the pipe is very important.For our 120 feet of pipe, about 3 percentof the heat energy in the water is lost onthe round trip. We used three-quarter-inchChlorinated Polyvinyl Chloride (CPVC)pipe for the supply and return lines. PEXpipe would probably also work well.We made the insulation for the pipes bycutting 8-inch-wide strips of 2-inch-thickextruded polystyrene (pink) insulationboard. Two three-quarter-inch grooves areLight reflected up off snow will increase the effectiveness of thecollectors. To avoid snow accumulation on the collectors, makethem vertical (instead of tilted) and add an overhang to the shed.gary reysa (2)
enewableenergycut down the length of each strip for thepipes to sit in. One 8-inch strip goes underthe pipes. Another strip fits on top of thepipes. The strips are glued together withpolyurethane foam insulation from a spraycan. The strips can be weighted or tied togetheruntil the foam cures.Heat DistributionWe decided to remodel our floors toinclude hydronic radiant heat. The solarheating and radiant floors make an efficientcombination, plus we didn’t like our oldfloors. We did this by removing the existingfinish floor and installing three-quarterinchplywood spacers with slots betweenthe spacers for PEX tubing. Aluminumheat spreader plates were used to improvethe efficiency and eliminate hot spots directlyover the PEX-Aluminum-PEX. Thisis a type of PEX tubing that has a layer ofaluminum sandwiched between two layersof PEX. The advantage is it expands muchless than standard PEX when heated, sofloor noises are less likely. It is also easierto install, because it retains its shape whenbent. After the PEX was installed, we coveredthe floors with laminate flooring.As a rough guide, three loops of about250 feet each (a total of 750 feet) wereenough to distribute the heat from the 240-square-feet of solar collectors.All of the floor heating loops start andend at a common point. One end of eachloop is connected to the supply manifold;the other end, to the return manifold.Water from the storage tank is pumpedinto the supply manifold, then out throughthe floor loops and back to the returnmanifold where a pipe takes it back to thestorage tank. If water from the storage tankis too hot to go directly to the floor, a mixingvalve installed in the supply line mixeswater returning from the floor loops withthe supply water to bring the temperaturedown to a level that is safe for the floor. WeHeat from the solarcollectors is distributedthrough a radiant floorheating system usingPEX tubing runningthrough aluminum heatspreader plates. Ahot water baseboardheating system isanother option.gary reysaused a commercial set of supply and returnmanifolds that included all the fittings, airvents, valves and temperature gauges.Automatic ControlsThe controls for the system are simpleand operate the system efficiently. A standardGoldline differential controller is usedto control the pump that circulates water tothe collectors. It senses when the collectoris hotter than the tank water and turns onthe pump.For the first month, we just notedwhen the tank temperature was above 90degrees and manually plugged in the pumpto circulate hot water through the floors.When the tank went below 90 degrees weunplugged the pump. This is surprisinglyeffective, and it gives you a good feel forhow the system is operating.I have since installed two electronicthermostats. The first turns on when thetank temperature is above 90 degrees, andthe second turns on when the room temperaturegoes below 70 degrees. These twoResourcesGary Reysa’s Websitewww.BuildItSolar.comSolar Site Survey (to check for shading)www.BuildItSolar.com/SiteSurvey/site_survey.htmCollector Absorber Plateswww.SolarEnergy.comDifferential Controller Goldline GL30(available from multiple sources)Electronic ThermostatsJohnson Controls A419(available from multiple sources)Twin-wall Polycarbonate Glazingwww.Greenhouses-etc.net/glazing/twinwall.htm(also available from other greenhousesupply outlets)Collector Pump and Circulation Pumpwww.IAQSource.com/ (search for“taco”); www. us.grundfos.com/
enewableenergythermostats are wired in a series, such thatthe pump is only turned on when the tankis hot and the house is cold. And, becausethe thermostats both run on 120 volt AC,there is no need for low voltage control wiringor relays.The control system is set up to use heatas soon as the storage tank is hot enoughto supply useful heat. Using the heat assoon as the tank reaches 90 degrees ratherthan waiting for the tank to get hotter increasesthe efficiency of the collectors andalso reduces losses throughout the system.For example, on a 35-degree day with fullsun, the collectors will operate at about 59percent efficiency if the tank water is at 90degrees, versus 42 percent efficiency if thetank is at 150 degrees.Performance DataHere is performance data for two sampledays from a recent January.Jan. 12, 2007: A very cold sunny day.At 10 a.m. when the collector started gatheringheat, the outside temperature was 20below zero! The collector warmed the storagetank water from a morning low temperatureof 85 degrees to 125 degrees inthe afternoon. This heat energy stored inthe water is the equivalent of 2 gallons ofpropane burned in a furnace of typical (85percent) efficiency.Jan. 27, 2007: A typical sunny winterday with a high of 30 degrees. The tankwarmed from a morning low of 85 degreesto an afternoon high of 132 degrees. Thisis the energy equivalent of 2 1 ⁄2 gallons ofpropane burned in a typical furnace.Cost and ReturnThe cost of the solar system componentswas about $4,200 total. This includesMontana tax credits and an allowance forsiding that would have been needed forthe shed if the collectors hadn’t covered thesouth wall. I estimate that the system willreduce our propane use by about 340 gallonsper year, now worth about $740 in ourarea. The simple payback period is about5 1 ⁄2 years (at the 2007 price for propane).Show off Your SolarWe’re always looking for photos ofattractive solar homes to possiblyprofile or feature on the cover ofMother Earth News. If you havephotos you’d like to share with us,post them online atFlickr.com/Photos/MotherEarthNewsOther OpportunitiesSolar heating of water for domestic usecould be included in the design. By preheatingwater when the full output of thecollector is not needed for space heating,the system would earn a greater return.You may want to use some of the collectorheat to warm your new collectorbuilding. You could use the venting schemedescribed above to provide heating. By usingsome of the collector output for heatingthe new building, somewhat less heat is collectedfor the house. But, the collector willoperate more efficiently with air flowingthrough the vent system. If you choose todo this, be sure to insulate and seal the newbuilding well.Gary Reysa is passionate about solarheating. He’s been fighting Old Man Winterwith solar heat since moving to Montana.If you have comments or questions aboutthis project, post them to this article onlineat www.MotherEarthNews.com, or e-mailthe author at firstname.lastname@example.org.Lessons Learned:You Can Build Your Solar System Even Better!While the project has been a success, and we are quite satisfied with how it works, there is always room for improvement. Here aresome things we would do differently:1. Use vertical collector panels (rather than tilted at 70 degrees). This would:• collect nearly the same amount of energy• be less likely to overheat in the summer• collect much less snow during snowstorms• be easier to build and easier to fully integrate the collector into the wall2. Include a small overhang with a gutter above the collectors. This would shade the top of the collectors in the summer, and thegutter would prevent snow melt from dripping on the collector glazing.3. Make the collector frames from 2-by-6s instead of 2-by-4s, which would allow room for more insulation behind the absorber platesand a little more space between the glazing and the absorber plates.4. Fully integrate the collector into the shed wall, so that the collector framing is the same as the wall framing. This could be donewith 2-by-6 studs at 4-foot spacing — perhaps with a heavier top and bottom sill — depending on the size of the shed. Thecombined sheathing and collector back could be applied to the inside surface of the studs. This would save some additionalmoney, material and labor.5. Include a layer of the polyisocyanurate insulation inside the storage tank plywood walls. This is the best place to put insulation,because there is no tank framing to fit the insulation around, and no thermal bridging. The tank could be made a bit taller to makeup for the lost volume.6. Reduce losses in transferring heat to the house by building the solar shed closer to the house and/or insulating the undergroundpipes even better.7. Connect the collector manifolds together using either unions or high temperature silicone hose instead of the soldered couplings.