Improving the Performance of an Existing House

If you have an existing house and just want to reduce your electrical bill and at the same time reduce your global warming emissions, there are still lots of options to choose from.

The fastest way to identify both problem areas and the best opportunities for improvement is to get an energy survey by a certified energy auditor. This will typically cost a few hundred dollars but may be the best investment of the project.

Regardless of whether or not you get an energy survey, the following are some suggestions you might consider.

LED Lighting

The least expensive thing you can do is also the one with the quickest financial payback: convert as many lights in your house as possible to their LED equivalents. LED lights use about 1/6 as much power as standard incandescent or halogen bulbs and half as much power as fluorescent tubes. For the most common screw-in bulb sizes, the savings in energy is enough to pay for the investment within the first year.

LEDs are available in a wide range of sizes, shapes, bases, and color values and last much longer than conventional equivalents – in the Demonstration House, we have not had to replace a single light in our nearly four years of operation. The only places they don’t work are very hot, such as ovens, microwave, and clothes dryer.

Energy Star® Rated Appliances

Home appliances are rated for efficiency by the Environmental Protection Agency (EPA. A yellow sticker should be affixed to each model that predicts its annual energy usage and compares that model to other similar models.

Simply taking those ratings into account when purchasing new appliances will reduce your electricity bill at little or no cost.

Heat Pump Water Heater

A conventional electric hot water heater works just like an electric tea kettle – a heating rod immersed in the tank of water keeps it at your desired temperature. A heat pump water heater works differently – it moves heat energy from the surrounding air into the water in the tank. It requires only about one-third as much energy as a conventional water heater for the same amount of water heating.

The unit looks similar to a standard water heater, but is taller because the heat pump sits on top of the water tank.

While prices vary somewhat, a heat pump water heater will likely cost about $850 more than a standard water heater. However, many local electrical utilities pay a $500 rebate to encourage their use, so the net difference is about $350. For average usage and at an electricity cost of $0.07/kWh, the savings in energy cost will pay you back the difference in about 2-1/2 years – a good investment by most standards.

Despite its advantages, a heat pump water heater might not work as well in either of two situations:

  • If the water heater is in a heated part of the house it will cool the air around it and thus require your heating system to replace that heat. This will approximately double the payback time if you heat with a heat pump.

  • Depending on where the water heater is in the house, the noise from the heat pump when operating may be disturbing. You should listen to one in person to judge for yourself.

Air Sealing

Many older homes are not well sealed, causing drafts and increasing the load on the heating system which has to heat the air that leaks in to room temperature. Look for and seal leaks in such places as:

  • Around doors when closed.

  • Around external wall penetrations: faucets, outside outlets, vents, etc.

  • Around inside wall penetrations: electrical outlets especially.

  • Where pipes enter the wall or floor below sinks and behind appliances.

  • Around ill-fitted attic access hatches.

  • Where pipes, wires, and ducts pass through the ceiling and into the attic.

Upgrade Wall Insulation

In our relatively mild climate, many homes have been built with poor or no wall insulation. Fortunately, there are options for insulating walls without tearing them apart. Contractors can blow in loose insulation or squirt in expanding foam insulation through a series of small, easily repaired, holes. You will be astounded by the difference that properly insulated walls will make.

This is a job for a professional. You should only work with a licensed insulation company for a blow-in insulation retrofit.

Upgrade Attic Insulation

Older homes were often built with little or no attic insulation and even newer homes were built under building codes that required only moderate insulation. Most frequently, the existing insulation will either be in the form of fiberglass matts or blown-in fiberglass or cellulose fiber.

Whatever is the case, adding more attic insulation will surely reduce your electric bill. Assuming the attic space is accessible, the simplest solution is to simply blow in additional loose insulation on top of the existing.

As with wall insulation, this is a job best left to professionals who wear the protective gear needed to allow them to crawl into the remotest corners with the blower hose without filling their lungs with bad stuff.

Duct Sealing

If your heating system uses ducts to distribute conditioned air around the house, it should be inspected for leaks and loose or missing insulation. An attic or under-floor duct leak is throwing away heated air which will be replaced by outside air that will then need to be heated.

Added Solar System

Regardless of what you do to improve the efficiency of your house, you should consider adding a rooftop solar electric system. Every bit of the power you generate is one you don’t have to buy from the local electric utility.

In order to make solar system installation worthwhile, you will need a south-to southwest facing roof facet that is not shaded most of the time. Talk to a solar installer abut what national and state incentives are in place to cover part of the cost.