There are dozens of low or even no cost energy saving tips out there, from changing your air filter to adjusting the temperature on your hot water heater. These simple changes often save you a bundle over the course of a year, but if you’re still not finding the savings you want, you may want to invest in some larger home improvement projects aimed at cutting energy use.

Here are the five things you can do at home, to save some serious energy dollars.

1. Install a high efficiency HVAC unit. Heating and cooling make up the largest portion of your energy bill—about 48 percent according to the U.S. Department of Energy. Replacing an outdated model with a new ENERGY STAR certified system could help keep some extra cash in your pocket each month. Installed correctly, HVAC systems with the ENERGY STAR logo could save you 20 percent on heating and cooling costs.

2. Add insulation. Even newer homes can benefit from added insulation. It acts as a barrier between the temperature inside your home and the temperature outside, so you save on heating and cooling. And even though adding extra insulation to your home can be costly, in just a few years you can recoup those costs in energy savings. Check ENERGY STAR's recommended home insulation levels before you get started.

3. Install a tankless water heater. Second only to your HVAC system in energy use is your hot water heater. If yours is in need of replacing, consider a more efficient option. Tankless, or on-demand water heaters, produce hot water as it’s needed. As a result, there’s no standby energy waste. A tankless system can be anywhere from 8 percent to 34 percent more efficient than a traditional model, depending on how much hot water your household uses. ENERGY STAR estimates that the average American family can save about $100 per year with a tankless water heater.  (They also have a longer lifetime—20 years—so you’ll find savings there too!)

4. Use a programmable thermostat. One of the easiest ways to save energy is to cut back. And with a programmable thermostat, you can schedule your energy savings without having to think about it each day. Program you air conditioner above 80° when you’re typically away from home. And schedule it to cool to an energy saving 78° before your return. Entry level programmable thermostats start at just $20, but more high-end models (which learn your habits and adjust the temperature accordingly), can cost upwards of $250. Even if you choose a higher-end model, you’re sure to find savings. Used properly, a programmable thermostat could save you up to $180 per year.

5. Replace your appliances. If your appliances are more than a decade old, they likely don’t meet today’s energy standards and add a good amount to your monthly electric bill. Whenever you’re in the market to replace them, shop for ENERGY STAR models, which will save you the most in energy costs. An ENERGY STAR certified refrigerator, for example, is about 10 percent more efficient than models that meet the minimum federal energy efficiency standard.