Let’s start at the bottom;
In your crawl space or basement you should find the duct work for your HVAC. Sealing and insulating your ducts increases the efficiency of your HVAC, which means lowering your utility bills as well as providing a more energy efficient and comfortable environment. Ducts with holes and rips waste an incredible amount of energy. Use foil tape or mastic to repair any holes that you find, or call a professional HVAC company to do it for you. Your ducts should also be insulated, use insulation with at least a R-6 rating. Duct sealant, also known as duct mastic, is a paste, which is more durable than foil duct tape. It is available at home improvement centers. Your HVAC may be in the attic as well. If so, see below.
While you are under the house it is a great time to check for cracks and leaks in the basements as well to avoid stacking – which is when air is drawn into the house through cracks in the basement and then is drawn all the up through the attic. Look at the top of the basement wall where the floor system meets the top of the foundation wall. If you find any; a sealant or caulk are good for cracks less than 1/4 inch. Use spray foam to fill gaps from 1/4 inch to 3 inches. It is recommended that you seal penetrations that go through the basement ceiling to the floor above. These holes are for wires, water supply pipes, water drainpipes, the plumbing vent stack, and the furnace flue.
Now’s let’s look in the attic;
Do you have any can lights (also known as recessed lights) anywhere in your home? If so, make sure that the light is insulated and sealed properly to avoid energy efficiency issues as well as safety issues, like fire hazards. It may be best to consult a professional before sealing can lights or coming into contact with electrical components. Never put insulation back over recessed light fixtures or soffit vents and keep it at least 3 inches from can lights unless they are IC-rated.
Look for large holes as sealing them is the greatest bang for your buck. Look for areas where walls meet the attic floor and areas of dirty insulation, (black/brown stains on the underside of insulation indicate air is moving through it). Next look for smaller holes and seal them as well. In cold weather you can also look for frost/ which will appear stained in the same places in warm summer months. Use expanding foam or caulk to seal the openings around plumbing vent pipes. When it is dry put the insulation back over it and cover it well.
Depending on how you get access to your attic you may want to put some weather stripping around the space you enter through and insulate the back of the door.
Stay tuned for many more energy saving tips to help your home be comfortable as it uses energy and saves your money.
Feel free to let us know how this info helped you, as well as any questions.