Energy Star rated products should be purchased when you need the item.  Only certain appliances are covered by this rating: dishwasher, clothes washer, refrigerators and freezers; ranges, room air cleaners; room air conditioners and dehumidifiers. 

HVAC (heating, ventilating and air conditioning) systems, should have the label. This includes boilers, ceiling fans, ventilating fans, heat pumps, furnaces and programmable thermostats. 

Home electronics that qualify are TVs, VCRs, battery charging systems, digital to analog conversion boxes, cordless phones, home audio systems and external power adapters. 

Lighting consists of light bulbs and their fixture. Fluorescent bulbs use 75% less energy than conventional incandescent bulbs and will last about 10 times longer. The downside is they contain mercury, which is toxic. Please recycle these, don't throw them in the trash or incinerate them! The LED (light emitting diodes) are even more efficient, using 90% less energy than the fluorescent bulbs.

Double paned windows and doors make a big difference. It may take years to recoup your investment, but you will do it a lot warmer/cooler. If you can't do this, you can use black out curtains to reduce the solar load in the summer. Other products are available, but be sure to assess its sustainability (Can it be reused or recycle? How long will it last?)

Solar Load is a phrase that refers to heat added by the energy of sunlight. Heat is energy. Sit by a window through which sun is streaming into your house in the summer. You will usually feel the difference. It's usually much warmer in the sun, even in your car with the AC going. To reduce the amount of heat coming into your home, you can close the blinds, plant some trees for more shade, put a reflective film on the windows, or perhaps install an awning that will shade the window. 

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Water heaters - European, tankless or hot water on demand water heaters are great. They take up minimal space and don't constantly heat the water. If you can't change to one of these, drop the temperature on the tank or turn it off completely, while you are on vacation, etc. Insulation jackets help reduce heat loss on conventional tank models.

Grey water is another option that may take a little work. Grey water is water from a household that is not sewage. It includes water from showers and baths, dishwashers and washing machines.  For more info on grey water click here.

Ceiling fans help by pushing air toward the ceiling and bringing warm air back down in winter. Reverse the direction in the summer and  you get a cooler breeze. If you're not sure which is which, turn it on high, see what that feels like, then turn it off. When it stops, flip the switch the other way and repeat. You should be able to figure out which forces air down towards you, and which one forces it up to the ceiling.  

Changing vent configuration with the season for multi story houses with one heating unit. Since warm air rises, close or restrict air flow from the vents on floors above the first story. This will force the warm air down to the first floor and let it rise upstairs. Done in conjunction with ceiling fans can help even out the temperature on different floors. 

Radiant or in-floor heating is an alternative to traditional central heat. Pipes are installed prior to the floor's installation. It is normally a system of tubes that carry heated water. As heat rises it warms the room from the floor up. How nice in the winter!

Fluorescent bulbs vs. Incandescent bulbs - we've all heard the fluorescent bulbs are more energy efficient. I have a circular one I've had for over 20 years! The only nice thing I can say about the incandescent bulbs is they warm up my bathroom quite nicely in the winter!! And yes, they make it too hot in the summer!

Insulation can make you so much more comfortable, and help keep your heating and cooling bills lower. This includes attic insulation, weather stripping around doors and windows, insulating electrical outlets on exterior walls, both inside and outside.

Humidifiers are invaluable in the winter. They can add the water to the atmosphere within the home. Warmer air holds more moisture than cooler air. It will feel warmer to you. Just think about how much warmer it seems in the summer when you're in a locale that has high humidity. Your skin, hair, clothing and furniture will benefit from additional moisture when humidity is higher in the winter. 

Heat Energy from our dryers is resource we let go out the door. In the winter, you can redirect the exhaust from the dryer and use it to help heat and humidify your home. Many commercial products are available, or you can simply unhook the vent hose from the wall and use some old panty hose as a filter bag tied to the end of the hose.

Heater and AC Maintenance should performed each season. Even though it's no guarantee it won't break, at least you've done your due diligence. Change air filters. If you don't, the air flow will become more and more restricted, making your system work harder and more inefficiently. If you have allergies, you'll want to do this to maximize allergen removal. Dress according to the season and keep that thermostat lower in the winter and higher in the summer. Use those ceiling fans!

Plumbing should be inspected routinely for leaks. When possible, replace water faucets, toilets and irrigation systems with EPA WaterSense labeled products.