The infrared photo at left shows radiant heat loss (yellow and red shading) in a typical residential window and door. It also reveals that the most grievous heat loss (purple, violet, almost black shading) takes place around the trim and edges of the opening. This is air infiltration, and it is your deadly enemy in keeping your house warm and dry and free of mold.
We’ve posted before on the hazards of air infiltration and moisture, and we’ve urged you all to arm yourselves with caulk, foam in cans, and sticky weatherstripping to fight the crannies that permit heat to escape and air to come in while you’re trying to heat or cool your house. Only in temperate spring and fall weather here in New England do we blithely throw open our windows and share the environment indoors and outdoors. In either high summer or deepest winter the potential for unpleasant temperatures and moisture accumulations indoors and makes climate control increasingly not just a luxury.
Enter the capitalist economy. Don’t fuss about with all that caulk and foam, say the strident voices on the radio and television; we can change your house’s energy performance in a jiffy with 1. new energy-efficient vinyl replacement windows, 2. new energy-efficient vinyl storm doors front and rear, 3. safe, energy-efficient blown-in insulation in attic and walls, no damage to your interior, 4. new, safe, “permanent” energy-efficient vinyl siding with optional foam insulation backing to save you lots of energy and money. And they take credit cards, and they have financial experts standing by to mortgage your house for the full amount.
No sudden moves, now. Will replacement windows perform startingly better than the wooden sash windows or vinyl double-hung you have now? Not if you reduce or eliminate air leakage ( infiltration) through and around your old windows. Then your old windows will perform nearly as well as any window on the market, give or take 15%. Surprised? Same story with the blown-in insulation and the vinyl siding. The best deal of the lot is the vinyl storm windows and doors. They reduce infiltration almost completely through your entry doors. The rest of the “home improvements” won’t pay for themselves any time soon.
The article linked here is from Journal of Light Construction on the subject of replacement windows and their rate of payback based on improved energy performance. The math doesn’t work. It takes a LONG time to payback the investment on new windows, doors, siding, and blown-in insulation. What takes a SHORT time to pay back? Anything that tightens your house, closes cracks, tightens doors and windows, and reduces air infiltration in and out. That’s the magic of home energy. Air. Stop it going in and out, you stop energy from being stolen from your house and your budget.
The boring conclusion is: nothing makes as big a difference in your house as caulk, foam and weatherstripping. Big ticket stuff like windows and viny siding works, eventually. But caulk and foam and gummy weatherstrip work today. If you hire a remodeler, handyman or do it yourself, it still works if you do it right. And it’s not too hard. Don’t hock the ranch before you’ve done the chores, ok?