Energy Analysis / Indoor Air Testing

Saving Energy: Weatherizing Your Home
Don’t let those hard-earned energy dollars disappear into thin air – a small investment in weatherizing supplies can make a big difference in your utility bills.

Infrared Thermal Imaging
Home inspectors rely on their trained eye to detect many of the problems that typically exist in buildings. But even the most highly trained inspector can benefit from the power of a thermal imaging camera, because it can detect what no eye can see — minor variations in temperature that can signal or moisture problems. For example, infrared cameras can detect moisture accumulating out of sight in a roofing system, electrical components that are overheating, and other problems.
An infrared camera can provide valuable information about the structual intergrity and construction of nearly any building. A trained thermographer can detect temperature anomalies in the building envelope which can indicate moisture intrusion, construction errors and mold growth. With an infrared scan, the fault can be pin pointed, preventing unnecessary repair work and saving valuable time.
Thermography is a useful tool for inspectors evaluating building structure, assessing energy performance, locating moisture intrusion points or examining structure degradation. Building owners will appreciate the visual evidence infrared cameras provide, and insurance companies and contractors will be given clear, indisputable examples of damage or faulty work.
Photos taken using an Infrared Camera


Blower door tests
If you’re not sure where to start weatherizing, a blower door test can be a great investment in tightening up your home.
How it works: Blower door tests are performed by certified energy auditors using special variable-speed fans. All windows and doors are closed, and the fan is installed in the front door with a special air-tight seal. As the fan is turned on, the energy auditor will monitor the flow of air through the fan, as well as the air pressure inside your home.
The benefits: Because your home is sealed and evenly pressurized, it’s easy to find out exactly where air leaks are occurring. In most cases, you can feel air leaks with your hand or see them with the use of a tissue or smoke pencil. While you’d probably expect to find drafts around windows and doors, you might be surprised to learn how much air can leak around electrical outlets and plumbing pipes. Blower door tests can also help identify sources of indoor air quality problems, such as carbon monoxide.
The cost: A blower door test will cost around $200-$500, depending on the size of your home. If you follow the advice you receive for weatherizing, you’ll recoup the cost of the test in energy savings in as little as two years!
Finding air leaks
The first step in tightening up your home is finding the air leaks that need to be sealed. Why? A 1/16th-inch unsealed crack around a window can let in as much cold air as leaving the window open three inches! An easy way to find air leaks is to hold a tissue between two fingers and hold it over the area – drafts will cause the tissue to blow around.
The chart to the right shows the primary places outside air infiltrates your home.
Most are easy to fix with some of the inexpensive weatherizing materials listed below.

Choosing the right caulk
The hardest thing about weatherizing your home is choosing the right caulk. The staff at your local hardware store or home center can help you find the one you need. Here’s what to look for:
What it’s made of: Latex and acrylic are easier to use than silicone, but they don’t last as long. They clean up with water, and they can be painted. Use latex or acrylic in cracks that won’t expand and contract beyond 1/8th of an inch. Silicone lasts longer and adheres better than latex or acrylic, but it sets up quickly, making it harder to clean up mistakes. This is the best type of caulk for gaps that may expand and contract. In addition, silicone cannot be painted – the paint won’t stick.
Where it can be used: Most silicone caulks work both indoors and outdoors, while some latex caulks should only be used indoors. Other caulks are formulated specifically for high-moisture areas like kitchens and bathrooms to fight mildew growth.
Durability: It’s worth the small extra price to get a caulk with a 50-year warranty.
Color: Choices usually include white, clear, gray or almond. Color choice is especially important with silicone caulk, because it can’t be painted.
The container: If you’re a home-improvement novice, spend a little more for the squeezable tubes – they’re much easier to handle than caulking guns, especially in small areas.
How much to buy: One canister of caulk is usually enough to weatherize two windows or doors.

Other weatherizing materials
A typical home will need about $50 in weatherizing materials – and the cost can be paid back in energy savings in just a few weeks.
Caulk is a homeowner’s best friend. The staff at your home center or hardware store can help you find the type of caulk you need. One canister is enough to weatherize two windows or doors.
Rope caulk is great for temporary use. It feels like modeling clay – it comes in a roll and peels off in a long strip. Use it around movable parts of windows and around doors you don’t use.
Expandable foam sealant works well in larger holes and crevices on the exterior of your home, such as air conditioner hoses. Be careful when using this product – it’s difficult to clean, and the rapid expansion can split wood if you use too much.
Window glazing seals the glass windowpane against the frame. Tap lightly on your windowpanes – if they’re loose, they’re leaking air. Glazing comes in canisters, tubes or rope.
Weatherstripping blocks drafts along the edges of doors and windows. It comes in strip of foam, or thin V-shaped metal.
Rubber or vinyl door sweeps and adjustable vinyl thresholds stop cold drafts from blowing in under your doors.
Outlet gaskets are thin rectangles of foam that fit behind the covers of electrical outlets and light switches. You’ll find these in the electrical section of the home center or hardware store.
Outlet safety caps, designed for childproofing, are also great for block air drafts. Look for these in the electrical section, or in the baby products aisle.

Caulking tips
If you’ve never used caulk before, practice on a scrap piece of wood a few times until you feel comfortable.
Caulking in three easy steps:
Make sure the area is clean and dry, so the caulk adheres properly. Use a utility knife or scraper to remove flaking paint and old caulk, then wipe away dirt and dust.
Apply the caulk carefully. Try not to leave gaps; if you drip or apply too much, wipe it away with a wet rag. If you’re sealing a wider crevice, force the caulk all the way in with a wide blade scraper.
Gently smooth out the bead of caulk. Use a plastic spoon, a popsicle stick or an ice cube. If you use your finger, be sure to wash your hands thoroughly when you’re done.
When you’re finished with a section, lay the caulking gun on a piece of newspaper – the caulk will continue to ooze out of the canister for several seconds. Let the caulk dry for a few hours before painting. If you have a partial tube of caulk left when you’re done, plug the end of the nozzle with a galvanized nail or a piece of wire hanger.

Exterior weatherizing
Start by weatherizing the exterior of your home in the back yard – by the time you get to the front and the inside, you’ll be a pro!
The primary areas to seal with caulk are:
The top and bottom edges of the rim joist – this is the thick wooden board that site on top of the concrete foundation and connects to the floor joists.
The outside edges of windows and doors. Don’t forget the basement windows!
Any opening on the wall of your house, including water spigots, electrical outlets, air conditioner hoses, dryer vents, and gas and water pipes.
If you find a large hole or crack, use expanding foam. A small squirt is usually enough to seal the opening – too much can damage the surrounding materials. Don’t use expanding foam around any electrical equipment.
If you have storm windows, use them. If you don’t, install plastic window film, especially on north-facing windows. Don’t forget to cover basement windows too.

Interior weatherizing
The best place to start interior weatherizing is the windows, because this is where heat loss often occurs. Double-hung windows are the draftiest because of all the moving parts, but older casement windows may also need to be sealed.
Weatherizing your windows:
Apply caulk around the outside edges of the window casing.
Apply glazing around the edges of the windowpanes. Scrape off old glazing and clean the glass; when it’s dry, apply the glazing where the glass meets the window frame. Press it tightly and smooth with a putty knife.
If you have double-hung windows, open the bottom sash and install adhesive-backed foam weatherstripping to the tracks and to the bottom of the sash.
Close the window tightly and use rope caulk to seal all the moving parts.
If you don’t have storm windows, install window film, either interior or exterior. Apply the tape around the outside edge of the window, apply the film and shrink it tight with a hair dryer.
Heavy drapes or curtains can also help hold back cold air, but remember to open them on sunny days to take advantage of the sun’s rays.
Don’t forget to caulk around the outer edges of basement windows and cover them with plastic film. Don’t use permanent caulk to seal basement windows shut – you may need quick ventilation in the event of a gas leak or carbon monoxide problem. Use removable rope caulk instead.


Weatherizing your doors
Apply caulk to the outside edges of the door casing.
Open the door and install weatherstripping to the inside of the doorjamb.
If the door has a window, apply glazing or clear caulk to the edges of the windowpane.
Stop under-door drafts with a rubber or vinyl door sweep along the bottom. In a pinch, a rolled-up towel can work too.
Replace the threshold under the door with a flexible vinyl gasket. Look for an adjustable model that’s easy to fit to the proper height.
If you have a side or basement door you rarely use, seal the edges with removable rope caulk.


Other areas to weatherize
Electrical outlets, especially along exterior walls, are a prime spot for cold air drafts. Carefully unscrew the cover and press a foam gasket around the sockets. Put the cover back on and insert childproof safety caps into all unused outlets.
The attic opening is another drafty spot. Install insulation over the back of the attic door; if you have hatch-type access, add foam weatherstripping around the top edges of the openings.
Wood fireplaces are notorious sources of air leaks. Tight-fitting glass doors are the best way to prevent air from escaping or entering. When you’re not using the fireplace, keep the damper closed and close the glass doors tightly. If you never use the fireplace, plug the chimney with insulation and seal the doors shut with silicone caulk.

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