Reduce Your Home's Energy Use and Carbon Footprint in NH

Reducing a household's environmental impact does not require a solar array or a six-figure retrofit. For most southern New Hampshire homes, the projects that meaningfully cut both energy use and household carbon footprint are unglamorous: air sealing, duct sealing, insulation, and right-sized high-efficiency equipment. Each one pays back twice, once in lower bills and once in lower emissions.

At A.J. LeBlanc Heating, we help NH homeowners prioritize the work that delivers the most benefit per dollar. Below are the steps that consistently come out on top.

Seal air infiltration into the home

If your home is not sealed to current standards, you may be spending 15 to 30 percent more on your energy bills than necessary. Air leakage means heat escaping in winter and cooling escaping in summer, with the HVAC system working overtime to replace it.

Common leak points in NH homes:

• Gaps around windows and exterior doors
• Penetrations for pipes, wires, and ducts that pass through walls or into the attic
• The rim joist where the foundation meets the first floor
• Recessed lights in insulated ceilings (use IC-rated airtight covers)
• Around chimneys, flues, and fireplace surrounds
• Behind kneewalls in finished attics

Caulk handles small gaps. Spray foam handles larger penetrations. Weatherstripping handles operable doors and windows. A home energy assessment can quantify your home's leakage rate and identify the highest-impact spots to seal first.

Seal ducts that run outside conditioned space

If your ductwork passes through an unconditioned garage, attic, basement, or crawlspace, leaks in those ducts dump conditioned air directly outside the parts of the home you actually use. Industry studies put typical duct leakage at 25 to 40 percent of system airflow in older NH homes.

• Use foil tape rated for HVAC use (UL 181) or duct mastic. Standard cloth duct tape is the wrong product despite its name.
• Focus on joints at boots, plenums, and takeoffs.
• Insulate ducts that run through unconditioned space after sealing them.
• For a complete fix, a contractor with duct-blaster equipment can quantify and seal leaks throughout the system.

Outlet and switch plate insulators

Electrical outlets and switch boxes on exterior walls are small but cumulative leak points. The hole cut for the box and the gap around the device let air pass through the wall cavity.

• Inexpensive foam outlet and switch plate gaskets install behind the cover plate in under a minute per outlet.
• Child-safety outlet plugs in unused outlets provide additional sealing.
• The cost is a few dollars per outlet. The cumulative impact across all exterior-wall outlets is noticeable.

Insulate where it pays back fastest

For most NH homes, the priority order is:

• Attic insulation: homes built before the 1990s frequently have less than R-30 in the attic. Current recommendations for NH are R-49 to R-60.
• Basement rim joist: a common cold-air pathway. Spray foam or rigid foam board cut and sealed in place addresses it.
• Pipe insulation: wrap hot-water and heating pipes in unconditioned basements and crawlspaces.
• Wall insulation: retrofit options exist (dense-pack cellulose or foam) but are more disruptive and have longer payback periods.

Upgrade to high-efficiency equipment

Once the house envelope is in better shape, upgrading the heating, cooling, and water heating equipment delivers the next round of savings:

• Cold-climate heat pumps in dual-fuel or all-electric configurations
• Condensing boilers with outdoor reset and ECM circulators
• Heat pump water heaters for electric domestic hot water
• Smart thermostats for automated setback enforcement

NHSaves utility rebates can substantially reduce the upfront cost of qualifying equipment, and financing can spread the rest. The federal 25C tax credit for this equipment ended December 31, 2025, and is not available for new installations.

Start with an energy assessment

A home energy assessment is the cheapest way to learn what your specific home actually needs. NHSaves typically heavily subsidizes the cost of an assessment for eligible homes, and the report identifies the highest-impact projects in priority order.

Need help building a plan?

If you want a professional look at where your home is leaking energy and what to do about it, contact A.J. LeBlanc Heating. Serving New Hampshire families since 1928.

Frequently Asked Questions

Which efficiency improvement has the fastest payback?

For most NH homes, air sealing and changing the furnace filter pay back almost immediately. Attic insulation and duct sealing are close seconds.

Is window replacement worth it for energy savings?

Window replacement is more about comfort than energy payback. The energy savings alone rarely justify the cost. Storm windows or low-e film can deliver meaningful comfort gains for a fraction of the cost.

What is NHSaves?

NHSaves is the brand for energy efficiency programs run by NH's electric and gas utilities. It funds home energy assessments, weatherization rebates, and equipment incentives for qualifying homeowners.

How do I know if my attic insulation is adequate?

If you can see the tops of the floor joists from the attic, you almost certainly need more insulation. Current NH recommendations are R-49 to R-60, which corresponds to roughly 14 to 18 inches of blown cellulose or fiberglass.

Are heat pumps actually lower-emission than gas heat?

On the current New England electric grid, yes, in most cases. The grid is increasingly low-carbon as coal retires and renewables and nuclear add capacity. A heat pump running on this grid produces meaningfully lower emissions than burning oil, propane, or even natural gas at the equipment level.