Irvin De La Paz – Mechanical Engineering Academic Projects

How to Lower your Energy or Electricity Bill 101

by Irvin De La Paz on 11/03/10 at 3:01 am

It is clear oil prices will continue the trend of increasing while supply continues  to decrease. These conditions means as time pass your energy bill will increase but what can you do to lower those energy bills? Wonder no more  as I will explain how anyone can lower their energy bill.

The secret to lower your Energy Bill

Mechanical engineers study extensively energy transformation and generation. Having a degree in mechanical engineering made me know some insight  you’ll  find valuable. Every appliance in your house has a  thermodynamic  (energy transformation) process. We mechanical engineers  have a little word called efficiency. Efficiency is nothing more than a number that represents how much work is done taking into account how much energy it takes (input) to do the work.  A high efficiency number means that more work is done with less energy input on the system.  This efficiency number  will never reach 100%. This is due because as energy is transformed, some of it is lost as heat, friction or another cause.

Okay now how can I use this efficiency knowledge?

A common strategy to lowering your energy bill is to increase the efficiency of your appliances. Increasing the efficiency of your appliances will make you consume less energy as more work is done with less energy. At a typical household the HVAC (Heating and Ventilating Air Conditioning) units are the one that consume most of your electricity bill. This category includes refrigerator, freezer and A/C.

How to Increase the efficiency of my Refrigerator or  Freezer

If you have a refrigerator or freezer there are several steps you can do to increase efficiency  the refrigerator or freezer.

1. Let it breathe. It should not be to close to a cabinet or wall, at least 2 in of clearance. Also don’t put your refrigerator close to a heat source (i.e stove, dishwasher, sunlight, etc)
2. Icemaker Off. Turning off your icemaker will reduce consumption of your refrigerator as much as 15 to 20 percent.
3. Defective door seals – Check your doors  for any excessive cold air leak
4. Temperatures should not be set to high. Acceptable temperatures are always on the default refrigerator and freezer set.
5. Clean the outside of condenser coils at least once every year .

Of course none of the solutions will work if you have a electricity hungry refrigerator or freezer. That’s why sometimes is better overall to replace a non-efficient refrigerator/freezer with a more efficient one.  The rationale behind is that  energy consumption over a period of time (typically 2 to 3 years) will cost the same  as buying a better one that consumes less electricity. Take into account that the typical refrigerator/freezer last 5 to 10 years.

When deciding what refrigerator or freezer to buy please look for energy star logo. I will go in more detail in how to know when to replace your appliance  for a more efficient one in a next post.

How to increase efficiency of my HVAC?

Living in a hot or cold climate, everyone knows  air conditioning units are sometimes not a luxury but a necessity.  There are many things you can do to increase the efficiency of that a/c unit.

1. Clean filters every month – A dirty filter restrict air flow, heating components inside the a/c and the cool air
2. Get the coil fins straight – sometimes the fins are deformed restricting air flow. A fin comb can be purchased on ebay.
3. Let your HVAC breath – Clean any obstruction (plant, dirt, bird nest that may restrict air flow from the outside of the a/c.
4. Let the shades begin – If your HVAC is facing south/ west,  a proper shade can increase efficiency. Blocking sunlight using shades on a window may help too.
5. Insulate the ducts – mastic tapes or sealer wrapped with R08 rated fiberglass insulation.
6. Check air leaks in your home . Typical air leaks may be holes or gap in  doors, windows, cables and plumbing.
7. Technician check – Hire a technician to check the coolant levels and clean  the coils. Up to 30% increased efficiency.

As the refrigerator/freezer ,  this solutions will not work if you have a deficient HVAC.  As mentioned before, please consider energy star alternatives. Also if your using an electric heater consider changing to a gas one, as they may be more efficient.

Increase efficiency of typical home items

• Lights – Changing your incandescent  lightbulbs for compact fluorescent lights will reduced 70% of  your lightning consumption  in your house typically 9% of your energy bill.

• Dryer machine  – Dryer machines that use gas are more efficient that ones that use electricity.
  • Heat pump dryers use up to %50 less energy than conventional dryers.

• Stove – Induction stove are up to  80 to 90% efficient compared to halogen stove (60%) electron coil / cast iron (55%)  and gas (40%)  according to the Department of Energy.

• Television and Monitors – Change  from  cathode ray tube CRT or projection  tv’s to lcd.  LCDs can consume up to 50% less than other CRT tvs.

From left to right, CRT, Projection, LCD

• Desktop Computers  If you have a desktop consider:

1. Changing to a laptop or netbook. Netbooks use up to 60% energy as conventional desktop.
2. Clean computer dust once every year. Dust may be situated on the motherboard and in the fans
3. Change power supply to a more efficient one.