Heating and cooling costs typically account for more than half of your utility bill, according to the Department of Energy. If you ask us, that is just crazy. So what can you do about it? How about “HVAC Hypermiling”?
What is Hypermiling?
The term hypermiling was originally used in automotive circles to describe people who drove intelligently to achieve significantly higher fuel economy than rated by the Environmental Protection Agency (EPA). The practice involves well-known methods like coasting down hills or slowly accelerating from a stop, but hypermilers go to far more radical ends to decrease their fuel consumption.
So What is HVAC Hypermiling?
Heating, ventilation and air conditioning (HVAC) hypermiling is the process by which you take any means necessary to reduce the amount of time your HVAC runs, thereby reducing the amount of money you pay for heating and cooling. HVAC hypermiling can be achieved through a variety of methods but here are two ways to make it work for you.
1. Seal Everything. Insulate.
This is one of the most simple and cost effective things you can do. Most houses in North Alabama have about 30% duct leakage. This means when you pay for $100 of cool air in the summer, only about $70 of it actually enters your house. Not cool. (Pun intended.)
Most North Alabama houses also have significant amounts of air leakage and are poorly insulated. You can do this stuff on your own with the right materials. And patience. Here is a short little guide from ENERGY STAR: http://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_seal_insulate
Of course you could pay a professional contractor to knock this out for you. It would set you back a few hundred bucks and a few hours. If you have a larger than average home, the cost may be a little over $1000. Even so, you’ll make your money back almost immediately.
2. Squeeze the Seasons
OK, this is the fun part. My wife and I play this game each year. Really it is just me and she is along for the ride. When her frown gets a little too big I know it is time to give in and turn on the HVAC. Here’s what I do.
I try to turn the HVAC off as early in the spring as possible and leave it off for as long as possible. I do the exact opposite in the fall. I’ll turn it off as early as possible and hold out until maybe early November. The better your home is air sealed and insulated, the better you will do.
When we have cool nights in the house we use blankets and extra clothing to stay warm. The house will warm up during the day so the objective is to endure a few hours of colder than normal temperatures to keep the HVAC from coming on. If the house is still cool and it has warmed up outside, the windows come open. Fans are used to circulate air and cool the house if it gets too hot. I refuse to turn the HVAC on until the temperature gets to 78°F in the Spring or 66° in the Fall.
Ready to push your HVAC hypermiling a little further? Sometimes you’ll have a spike or a drop in temperature. Sometimes you’ll feel the humidity creep up a little too high. No worries. Run the HVAC. Then shut it off and hold out again.
Here’s an example. Let’s say it is Spring and the temperature is 80 degrees Fahrenheit in the house and you can feel a little humidity. You know that the next few days will be cool but just need to make it through this warm spell. Turn the HVAC on and cool your house below what you normally would. Say 70°F. Once the temperature hits 70°, shut of the HVAC. This will allow you a few degrees of warming once the HVAC turns off and before the sun sets. Once you make it though this specific day you know you have a few good days ahead again. The key is to use the HVAC system sparingly just to re-balance of sort.
One last note… Make sure to track your humidity as well. The last thing you want is to save a few bucks on HVAC costs only to let the humidity get so high your floors buckle.
Have fun saving and let us know some of your results!