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SAVING ENERGY IN THE OLDER HOMEALFRED E. OVIATT, JR. and THEODORE J. BREVIK

CONTENTSIT’S WORTH YOUR WHILE!, 1ENERGY SAVING BEGINS WITH STOPPING LEAKS, 1

LEAKS, 1FINDING LEAKS, 1WEATHERSTRIPPING, 2

YOUR PLACE IN THE SUN, 4LETTING THE SUN IN, 4KEEPING THE SUN OUT, 5

ROOF VENTILATORS, 6STORM WINDOWS AND DOORS, 6WRAPPING IT UP, 7

INSULATE CEILINGS, 8INSULATE WALLS, 9INSULATE FLOORS, 10INSULATE DUCTS AND PIPES, 10VAPOR BARRIERS, 11

FOR FURTHER STUDY, 12

IT’S WORTH YOUR WHILE!Our national fuel shortage is now clearly visible. We must conserve our supply, and buy time todevelop new sources.

There are many ways to reduce energy waste, often at no cost or discomfort. In fact, some simpleimprovements in older homes can yield large savings-savings in energy and money.

Whether you keep your home for years or sell it next month, you have a golden opportunity toinvest in your property at a high return and little risk. You can get your money back with interest.

ENERGY SAVING BEGINS

LEAKSChances are your older home has someleaks. Not water leaks in the roof or base-ment, but leaks of air-air laden with heatenergy (and money). You may be heating(or cooling) all the air in your house overagain every hour, or less.

Leaks are more common in the older home;it often was built less tightly, without wea-ther-stripping or complete sealing, withoutvapor-seals. Time has caused wear or warp-ing, and dried out putty and caulking.These leaks can be worse in wasting energythan having no insulation, but they cost alot less to fix. Leaks can account for up toone-third of your energy losses. So this isthe place to begin saving energy in yourhome.

WITH STOPPING LEAKS

FINDING LEAKSWhere do you look for leaks? Windows anddoors are a starting point. Most windowsand doors do not fit tightly in their frames;they need some tolerance to operate. Wea-ther-stripping can seal these cracks withoutbinding. Do you feel a draft near your win-dows and doors? On a cold or windy day,place your hand over cracks to check fordrafts (or carefully use a candle flame.)Look for existing weather-stripping; is itmissing or worn and ineffective? Check theputty or caulking around glass, and aroundthe outside of frames. Is it old and dry,cracked or falling out? If so, the frameneeds resealing.

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Poke around at the bottom of the siding,where it laps over the foundation. Is therea big opening there? Stuff it with foam-rubber or insulation, or even old newspa-pers. Look at intersections of exterior wallsor where a wall butts against a chimney. Dothese points need recaulking? How aboutpipes, conduits or vents through outsidewalls? Any leaks around them? If bath ven-tilators go on with lights, they waste heat.Install separate switches.

Don’t overlook hatches or doorways intoyour attic or crawl space. Use weather-stripping around all edges, the same as withwindows and doors. Check around thechimney in the attic. Is there a big spacethat lets heat escape into a cold attic?Stuff it with a fireproof material, like min-eral wool. Don’t use newspapers here: thechimney gets hot. The same goes for radia-tor pipes, passing through floors or walls,and electric fixtures in the ceiling. Be surethat recessed ceiling fixtures are properlyventilated. Patching plaster makes a goodsealer where there is heat.

WEATHER-STRIPPINGCaulking cracks and stuffing holes requireslittle skill. Caulking can be neatly donewith a tube or gun applicator.

Weather-stripping merits a second look.There are many varieties; they vary slightlyin use and some are more durable thanothers.Spring metal strips are a common type andare the most durable, though a little diffi-cult to install. They are tacked inside adoor jamb, at sides and top, in the channelof sliding windows, at the closing rails,and on one side of the meeting rails. Pivot-ing windows are treated like doors.

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Tubular gasket types, whether flexible witha nailing flange, or rigid with a wood ormetal backing, are quite durable and easyto install. Those filled with sponge-rubberor plastic and with reinforced flanges, arelikely to last longest. They are tacked todoor stops at sides and tops, so the tubingis compressed when the door is closed. Onsliding windows, they are nailed at the sidesto window frames and at the sashes to therails. They can be placed inside or outside.They will stay resilient longer inside, butare more noticeable.

Foam or felt strips are less durable, andshould not be used at points of wear, as atsides of sliding windows. Foam comes ad-hesive-backed, but some felt strips requiretacking. Their application is simple, andthey are adequate for many uses.

Threshold seals at door bottoms are veryimportant, as cracks here may be large.Most threshold seals have replaceable vinylclosures. Some are mounted on the flooror threshold, some on the door.

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YOUR PLACE IN THE SUNWe tend to take the sun for granted, andgive it little thought. We forget that it isthe source of all our energy: of all the gasand oil and coal, of all the wood and wheatand corn, of all the water-power, on ourearth. It continues to radiate light andwarmth to us every day, and we don’t geta bill every month to remind us.

Much can be done in designing a new hometo get maximum solar benefits, but it’s nottoo late to improve your older home. Youcan’t change its orientation or location, orbuild it into a hillside, but you can do themost with what you have.

The sun warms your home by radiation toall its exposed surfaces. Some of this heat isreflected, depending on the nature and angleof the surface. Some is stored in the con-struction; some passes through to warm theinterior. We can keep heat out by paintingwalls a light color, by more reflective roof-ing, or by shades or blinds in windows. Wecan keep the sun out by shading with over-hangs or other devices. Or we can absorbmore solar heat by using dark surfaces andby taking full advantage of glass areas. Howwe want to control solar heat dependsupon outside temperatures.

In the north, in winter, we want to absorball we can get to reduce the heating load.In summer, we want to keep heat out.This is the object, much of the time, in hotclimates.

The indians of the southwest learned longago to reflect heat with light colors, and touse few, small windows, and thick walls ofadobe to store heat for the cool nights.

LETTING THE SUN INYour home is a natural “heat trap.” Solarheat accumulates through all its surfaces,but most of it streams through the trans-parent glass areas. These can be “solar col-lectors” in winter, when the low sunstrikes south-facing glass more directly, ad-mitting a large proportion of solar heat.

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Windows facing south, southeast, or south-west are best for this. They absorb moreheat in winter than do east or west win-dows, and are easier to shade against sum-mer sun. To take full advantage of wintersun, use drapes or curtains that can beopened full in south windows. Keep themclosed on cold nights or sunless days, toreduce outward radiation.

KEEPING THE SUN OUTIn the summer or in hot climates, you willwant to exclude solar heat, and to take fulladvantage of your windows as ventilators.If you have air-conditioning, keeping thesun out costs less than pumping it out.Many homes have roof overhangs, designedto exclude the high summer sun by shadingsouth windows. A covered porch can dothis too, as can tall shade trees (that losetheir leaves to admit the sun in winter).

But if you are blessed with none of these,there are some useful devices you can use.Exterior shades are most effective: allshades absorb some heat, so it is better ifthe shades are outside than inside the home.Louvered projections above the windowscan be attractive and economical; youmight do-it-yourself. These can be designedto block the high summer sun, but to admitsolar heat in winter. Awnings are an alter-native. Operable shutters are an old de-vice: if louvered, they permit air circula-tion; if solid, they reduce conducted heat.Louver-type insect screens are also obtain-able, and can stop about 80% of sunlight onthe south side. Interior Venetian blinds orlight drapes can reflect most solar heat, butheat they absorb warms the house.

East and west windows are more difficultto shade effectively since sun is lower, sothey admit far more solar heat in summermonths than a similar south window. Old-time operable shutters will work, but theyblock both light and view. Awnings andlouvered screens are less effective here.Most effective for east and west windowsis a combination of tall deciduous trees,and lower protective shrubbery. A verticalsunshade like a louvered fence can help. In-terior venetian blinds or light drapes, again,reflect some heat but also absorb heat.

Solar heat is not a problem with north-fac-ing windows, and this may make them high-ly desirable in hot climates, but in cold wea-ther they lose a lot of heat by conduction,without yielding any solar gain. In fact, ifyou have some north windows you don’tuse, as in a bath or extra bedroom, youmight consider filling the space with insula-tion and closing off with plywood.

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ROOF VENTILATORSAttics or other roof spaces are usuallyventilated to dispose of moisture from liv-ing spaces. This is particularly importantwhere no vapor barrier was used in the ceil-ing. Good ventilation can also greatly re-duce high attic temperature in the summer,keeping living spaces cooler. Screened ventsare usually provided in roof overhang sof-fits, with a higher roof ventilator near theridge, or at gable-ends. This allows naturalair circulation through the attic. Powerventilators can also be used when solarloads are high, cutting in automatically ata given attic temperature.

STORM WINDOWSAND DOORSWe have looked at problems of air leaks inwindows, and their transparency to radiantheat. They share a third problem withdoors: both are poor thermal insulators, andboth lose a lot of heat by conduction.

A single-pane window may lose twentytimes as much heat as an equal area of well-insulated wall. Double glass can cut thishigh loss in half; triple glass to one-third.

In an older house, the least costly solutionis to put on storm windows. They will cutconduction losses roughly in half, the sameas double insulated glass, and further reduceair leakage, too.

A sheet of six-mil polyethylene plastic cando the job. Tack it to the outside of thewindow frame, or tape it to the inside. Thelatter is easier and protects the plastic; itwill hinder the view, but it’s cheap and willsave a lot of heat.

For better permanence at higher cost, singlepane storm windows can be used. Thesenormally can’t be opened for ventilation,and are usually replaced by screens in thesummer. But it is possible to hinge a few ofthem at the top, and buy hardware to swingthem open for ventilation.

Combination windows, (with screens), arethe most convenient kind. You can leavethem in place year-round, and most can beremoved for washing entirely from the in-side. They are also the most expensive.

A solid wood door has about the same con-duction loss as a window with storm sash,but air leakage will be higher. In the colderregions, glass storm doors will save heat, buttake longer than windows to pay for them-selves. Combination storm doors (withscreens) are a convenience and allow ven-tilation. If you live in a mild climate, andhave screens, don’t worry about stormdoors. If climate factors are extreme, hot orcold, consider replacing your doors withspecially insulated ones, or adding solidwood storm doors.

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WRAPPING IT UPWhen you want to keep something warm orcold, you wrap it up in a blanket; this iswhat insulation is. Like a good blanket, itcosts money and comes in several qualities.

Before you buy insulation, there are twothings you need to know. First, insulationslows the passage of heat; it lets your fur-nace burn at a slower rate, or less frequent-ly, saving fuel. But the amount of fuel savedis not proportional to the thickness of in-sulation. If you apply one inch of insula-tion, say that it saves 153 units of heat perhour. If you apply a second inch, it willsave only 48 units-less than one-third asmuch as the first. The tenth inch will onlysave 2 units!

You reach a point where another inchdoesn’t pay for itself-so you can have toomuch insulation. When adding smallamounts to existing insulation is difficultand costly, forget it, and look at less costlyways. Look harder for leaks; put storm win-dows on the north side; add attic insula-tion instead of opening up the walls.

The second thing you need to know aboutinsulation is about " R" factors: "R "

stands for resistance to heat flow. All build-ing materials have some " R" value; thisvalue is high for insulating materials. It ismarked on the label by manufacturers, andis proportional to the thickness used. Youruninsulated frame walls may have an " R"value around 4, the sum of the values foreach material in it. If you add R11 insula-tion, you get a total " R" of 15.

" R" is a relative value; energy savings arenot proportional to " R" either and each in-crease results in smaller savings. The " R "value you ought to have depends uponyour climate and the local cost of yourfuel. The cost of insulation is also a factor,including interest on your investment. Inan older house, there are usually practicallimits imposed by the construction.

In much of the United States, youshould have at least R19 in ceilings, andR11 in walls and in floors over unheatedspaces. In milder parts of the south, whenair-conditioning is not used, less may beenough. In north central areas, the northernhalf of New England, and most of Alaska,you need more if costs make it practical,as much as R38 in ceilings and R19 inwalls. Much depends on how much youalready have, and how much savings youcan gain at diminishing returns.

INSULATE CEILINGSAn unfinished attic with exposed joists iseasiest to insulate. You can use fiberglassor mineral wool batts or blankets, loosefill of mineral wool, cellulose or vermicu-lite. If you do it yourself, the fiberglassbatts are probably easiest to handle, andcan be placed quickly and neatly. If younow have no insulation, buy batts with avapor barrier and place the barrier on theceiling side. If adding insulation, buy battswithout barrier, or remove the barrier.

When joist spaces are full, you can build upa second layer of batts over the joists, ifyou want to go to 10 or 12 inches. Lay thesecond layer at right angles to them. Keepthe skin covered and wear work gloves; thefibers can be irritating. Keep batts backfrom the eaves, so they don’t block eavevents.

You can also pour the loose types fromtheir bags, but this type is harder to getlevel. You can do it with a board, or theback of a rake. Wear a respirator with themineral types, as you will raise some dust.

If your attic has a floor, you will have toremove some boards, or drill holes. Havea contractor fill the joist spaces withblown-in loose fill.

If you have a finished attic with knee-walls, you need to enclose the heated space,(see illustration p. 11) including end walls.Batts are probably best, with vapor barrierson the warm side. Stud depths and rafterventilation space will limit possible " R "values.

CAUTION: Do not place any kind of insu-lation over recessed light fixtures, or with-in 3 inches of light fixtures or hot exhaustflues. Use blocking to maintain this clear-ance.

INSULATE WALLSFrame walls in an older home can be in-sulated with blown-in loose fill types, usual-ly mineral wool or cellulose fiber. Urea-formaldehyde foam is also used. All areforced in through holes drilled in the out-side or inside walls. Often the outside iseasiest to restore, after removing one orseveral rows of clapboard or shingles todrill the holes. All stud spaces must becompletely filled, often requiring severalholes in each stud space. Special equip-ment and expertise is needed, so it isnormally contractor installed.

Choose a contractor carefully: there are alot of fast-buck artists around. Check yourlocal better business bureau. Get estimatesfrom several firms. How long have theybeen in business? Ask for and check cus-tomer references. Do their products meetfederal or industry standards?

In a standard wood-framed wall, " R" val-ues added will run about: 11 for mineralwool, 13 for cellulose fiber, 13 or 14 forureaformaldehyde. Comparative costsshould run in the same order, so you canjudge the best value. Remember that youare buying " R"s, so divide the total priceby the above values to get dollars per " R "for each type you price. In colder areas, itcould pay in energy costs saved to use thebetter insulators at some premium per " R " .

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Masonry walls, as in a heated basement orcrawl-space, can be furred out and insulatedwith batts. But the new foamed plasticboards have higher " R" values and aremoisture-resistant. Polystyrene or poly-urethane boards can be easily installed withadhesives. But they should be covered withadhesive bonded panels or gypsum board toprovide fireproofing.

INSULATE FLOORSFloors over unheated spaces can be easily in-sulated with batts. Start at one wall and sta-ple chicken wire to the bottom of the joists.Slide the batts in the opening with vaporbarrier up. Use short pieces of wire and battsto make it easy. Make sure space is filled.

If the batts are about 3-1/2”, (R11), therewill be an air-space above. But if you usebatts with an aluminum foil vapor barrierhere, the reflective layer at the air-space willincrease " R" to 13. If there is a gypsumboard ceiling, as in a garage under livingspaces, remove enough of the center area toslide batts to the walls. Support the centerbatts with a few wires until you can replacethe gypsum. Gypsum is hard to salvage;plan to replace with new material. Be sureto put it back-it is your fire barrier.

INSULATE DUCTS AND PIPESHeating or air-conditioning ducts in yourattic, garage or crawl space, or any otherunconditioned space, need insulation. Heat-ing ducts in a basement partially warm itand this may be desired.

The amount of insulation to use dependsupon temperature difference, inside to out-side, of the duct. Heating ducts in a coldattic need 4" mineral wool blankets; air-conditioning ducts may do with 2", if out-side temperature is not excessive. For air-conditioning, use batts with a vapor bar-rier, placing it on the outside.

Batts are wrapped around in short sections,with the joints sealed with special tape.Don’t wrap too tightly, especially on rec-tangular ducts. Tape any leaks in the ductjoints before wrapping.

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Insulate your steam or hot water pipes toreduce heat loss, unless you want some ofit in an unheated basement. (Insulation oncold water pipes can prevent condensation;dripping in a humid basement can bestopped with “anti-sweat” pipe covering.)Some pipe coverings are made in tubularform, split in half for application, in sizesto fit standard pipes and fittings. ‘Otherscan be wrapped around, or even “painted”on.

VAPOR BARRIERSVapor barriers are materials which resist va-por passage. Aluminum foil or polyethylenesheet are good examples. Kraft papers lam-inated with asphalt are sometimes built intoinsulation blankets. Vapor barriers arerecommended in colder climates; a rule-of-thumb is use them in any area where averageJanuary temperature is below 35° F. Vaporbarriers are placed in all parts of the build-ing envelope where insulation is normallyused, between heated spaces and the out-side. They go near the inside surface, onthe warm side.

In winter, there is a large vapor pres-sure difference between heated in-side air, and cold, dry outside air.This pressure forces gaseous wa-ter vapor through most buildingmaterials. When it reaches acolder surface, it can con-dense into water within theconstruction, or cause paintto blister on the outside. Avapor barrier prevents orretards this passage ofwater vapor.

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A vapor barrier may also be needed to pre-vent ground moisture from reaching woodframing, where it can condense and causedecay, as in a crawl space in any climate.Here it is placed directly on the ground.

Older homes built 20 years or more agooften do not have vapor barriers, and usual-ly little or no insulation. When insulationis added the need for a vapor barrier in-creases. But it may not be practical to ap-ply a vapor barrier in a wall, or under a lay-er of existing insulation in a ceiling. Whenit comes to tearing out plaster or gypsumboard, you may prefer to experiment with-out a vapor barrier. The need depends on:interior humidity, the number in your fam-ily, the degree of water use, and the ven-tilation. Good attic ventilation can be anadequate substitute.

If you see signs of a problem, such as stain-ing in the ceiling or paint peeling on out-side walls, a good oil paint on the interiorwill give a fair vapor seal. There are vinylwallpapers that would work well. Youcould try these first in baths or kitchens,where humidity is often high.

FOR FURTHER STUDY1. "Tips for Energy Savers," Federal Ener-

gy Administration, Washington, D.C.20461, (free).

2. " Making the Most of Your Energy Dol-lars," 1975, U.S. Dept. Commerce, Na-tional Bureau of Standards, for sale bythe superintendent of documents, U.S.Government Printing Office, Washing-ton, D.C., 20402, price 70 cents.

3. " In the Bank. . . Or Up the Chimney?"1975, Department of Housing and UrbanDevelopment, for sale by the superin-tendent of documents, U.S. GovernmentPrinting Office, Washington, D.C. 20402price $1.70.

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The information in this publication was authored by Alfred E. Oviatt Jr. of the U.S.Department of Agriculture, Forest Products Laboratory. Theodore J. Brevik, pro-fessor of agricultural engineering, College of Agricultural and Life Sciences,University of Wisconsin-Madison and Division of Economic and EnvironmentalDevelopment, University of Wisconsin-Extension has reviewed the information inthis publication and has determined it is appropriate for use in Wisconsin. This is ajoint publication of the agency and the institution.

This publication is slightly revised.

UNIVERSITY OF WISCONSIN-EXTENSIONUnivers i ty of Wisconsin-Extension, Gale L. VandeBerg, d i rector , in cooperat ion wi th the

United States Department of Agriculture and Wisconsin counties, publishes this informationto further the purpose of the May 8 and June 30, 1914 Acts of Congress; and provides equalopportunities in employment and programming including Title IX requirements. This publica-tion is available to Wisconsin residents from county Extension agents. It’s available to out-of-state purchasers from Agricultural Bulletin Building, 1535 Observatory Drive, Madison, Wiscon-

MARCH 1980 sin 53706. Editors, before publicizing, should contact the Agricultural Bulletin Building to de-

25¢termine its availability. Order by serial number and title; payment should include price plus

postage.

G2911 SAVING ENERGY IN THE OLDER HOME