home insulation and reduced heat loss | benefits of home insulation
TRANSCRIPT
Home Insulation And Reduced
Heat Loss
• An Overview of the Industry The industry of insulationmaterials have seen an evolution over a period of time.• From being used in the packaging of various productswith its application being put to use in industries as wellas households, insulation materials have now come to beused in the construction purposes and that is where theyhave found their real value.• Being able to reflect the heat and the cold that thenature has to offer, these sheets have managed tomaintain a comfortable environment for people staying invery warm and equally cold areas.
What is the Insulation?• Insulation—silently hidden in your walls, nomoving parts to fix—is a material you probablyspend precious little time thinking about.• Then along comes subzero (or sweltering!)weather, a three-digit utility bill or chilly drafts,and you start thinking about it a lot!• At home, you ponder whether it’s worth thetime and expense to add it to your ceilings,walls and basement.• At the store, you ponder which type,thickness, width and density to buy. And whenyou install it, you wonder just how good is“good enough.”• We asked insulation manufacturers andinstallers which questions they field most—andwhich blunders they see most. Following are sixthings they (and we) think you should know.
Choosing Insulation• Insulation products come in two main categories — bulk and reflective — which aresometimes combined into a composite material.• For the many different products available see ‘Insulation types and their applications’below.• To compare the insulating ability of the products available, we need to look at their R-value, which measures resistance to heat flow.• The higher the R-value, the higher the level of insulation. Products with the same R-valuehave the same insulating performance if installed as specified.• Check the information supplied on the product, including the R-value, the price persquare meter and whether it must be installed professionally or can be DIY — some typesof insulation require the use of masks and protective clothing.• Ensure that it suits your particular application and fits within the space available. Ask ifperformance guarantees or test certificates are available.• All insulation materials that are sold in Australia must meet Australian Standard AS/NZS4859, materials for the thermal insulation of buildings, even if they are imported.• Compare the environmental benefits of different products.
Insulation Types And Their Applications• Bulk insulation mainly resists the transferof conducted and convicted heat, relyingon pockets of trapped air within itsstructure.• Its thermal resistance is essentially thesame regardless of the direction of heatflow through it.• Bulk insulation includes materials such asglass wool, wool, cellulose fiber, polyesterand polystyrene.• All bulk insulation products come withone material R-value for a given thickness.
• Reflective insulation mainly resists radiant heat flowdue to its high reflectivity and low emissivity (ability tore-radiate heat).• It relies on the presence of an air layer of at least25mm next to the shiny surface.• The thermal resistance of reflective insulation varieswith the direction of heat flow through it.• Reflective insulation is usually shiny aluminum foillaminated onto paper or plastic and is available assheets (sarking), concertina-type batts and multi-cellbatts.• Together these products are known as reflective foillaminates, or RFL.• Dust settling on the reflective surface greatly reducesperformance.• Face reflective surfaces downwards or keep themvertical.• The anti-glare surface of single sided foil sarkingshould always face upwards or outwards.
Where to install insulationRoofs and ceilings work in conjunction when it comes to insulation.• Install insulation under the roofing material to reduce radiantheat gain.• Install insulation in the ceiling to reduce heat gain and loss. Inmost cases ceiling insulation is installed between the joists (seeInsulation installation).External walls should be insulated to reduce radiant, conductedand convicted heat transfer. Wall insulation can be installed:• within cavities• within stud frames• on the outside of stud frames• on the inside or outside of solid walls.
Installation Increases The insulation’s R-value By Over 20 Percent
The most important steps you can take:• Fill the stud cavity from top to bottom and side to side. To avoidguesswork when insulating walls built from standard 92-5/8 in.long studs, purchase and install precut fiberglass batts that are 93in. long and 15 in. wide. When you have to custom-cut batts at wallcorners and other places, cut the batts 1 in. higher and wider thanthe cavity you’re filling.• Split your insulation so half goes in front of and half goes behindelectrical wires. Compressing insulation reduces its R-value.• Around electrical boxes, notch, rather than compress, the batt —then tuck the cutout behind the box. To help prevent frozen pipes,insulate only on the cold side.
How much insulation is enough?
• The high-density insulation on the right, with more fibers and airspaces, can deliver up to 35 percent more insulating value thanstandard insulation.• The payback period for retrofitting insulation varies greatly, butstudies show that added insulation usually pays for itself in savedenergy costs within 5 to 10 years.• In Minnesota, a typical payback period might be five or six years.Payback in more temperate areas takes longer, but remember thatinsulation reduces air conditioning costs too.
