Wheatherization Guide: Air

Benefits of Leak Sealing

Save Energy and Money

If you live in an older house that has not been fully weatherized, somewhere between 20% and 50% of your heating and cooling bills can be attributed to air leakage alone. You may be needlessly losing hundreds of dollars each year as heated or cooled air slithers through the cracks in your home.

Sealing air leaks is the first step in a program to improve the energy efficiency of your home. The energy, time, and money you spend will pay for itself quickly - often in one winter! A thorough job of leak sealing can cut your home's total air leakage by 33-46% - reducing your heating and cooling bills up to 20%.

Once air leakage is controlled, insulation can reduce your bills by another 25-75%!

Improve Comfort Levels

Reducing air leakage and proper insulation help in the winter to stop uncomfortable drafts in your home. They also make it easier to maintain adequate humidity levels for indoor air. The amount of cold dry air which enters and warm moist air that leaves your home is reduced. In summer you can get the opposite advantage, keeping dry, cool air indoors where you want it.

Maintain Air Quality

Unweatherized older homes leak 4-5 times more air than is necessary to maintain adequate air quality. Most of this air leakage occurs where you need it the least - in your basement and attic. By taking the steps described below you can greatly reduce air leakage in an older home, while also maintaining air quality.

Caution: It is advisable to test your basement for radon, especially if you are going to seal it thoroughly. If you also thoroughly seal the other living areas of your home, you should pay careful attention to managing air quality. When effective sealing reduces infiltration and exfiltration nearly to zero, toxic fumes from household items - from cleaners to carpets - can build up to serious levels.

Reduce Moisture Damage

Tremendous quantities of moisture are generated inside the home from bathing, cooking, laundry, plants, and people. Moisture also enters through basements and crawl spaces. Warm air can leak into your cold wall cavities and attic, carrying moisture which can then condense. If unchecked, moisture may contribute to the deterioration of building materials and reduce the effectiveness of your insulation.

Table Of Contents

MEO's Weatherization Guide Introduction

Air and Insulation Introduction

Air Leakage

Insulation