Upon opening the last power bill we got, I nearly had a heart attack. The bill had doubled with no apparent reason. After the initial shock wore off, I decided to do something about the amount of electricity and power in general we use in the home. This is the first of three research post.
I started this project off like any of the others I’ve done by doing some research on the topic. I wanted to identify common usages, overall understanding of the technologies involved, factors I’d have control over and break down by cost what I could accomplish to conserve power.
In an average American household energy consumption breakdown is;
50-70% HVAC
10-30% Lighting, appliances and other devices
20% for heating water
HVAC
Heat Transfer and Insulation
Heat flows naturally from higher temperatures, warmer spaces, to lower ones.
The R-value of insulation is the thermal resistance value. The R-values are added together when calculating multiple layers of insulation.
The overall R-value of a wall can be different from the R-value of the installed insulation. The joists become a thermal short circuit because of the conductive properties of the wood. So the heat will pass through the path of least resistance which is the joists.
Radiant Barriers
Radiant barriers consist of a thin reflective material such as aluminium. This film is usually applied to one or both sides of a substrate. An example of this is the Prodex which is a foil – foam – foil product.
A radiant barrier works by reducing the heat transfer by thermal radiation.
HVAC Conservation Tips
I came across these good tips from a variety of sources like Nevada Power that cost little or no money. Some are specific to my region.
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Install programmable thermostats
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Recommended thermostat settings
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Summer – set thermostat to 78 – 80 degrees when home and 5 – 10 degrees warmer when your not home or asleep
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Winter – set thermostat to 68 degrees when home and back to 58 degrees when sleeping or on not home more than 4 hours
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Use your window blinds to help control the heat
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Summer – close the blinds during the day to help keep out the heat
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Winter – open the blinds on the sunny side of the house to help heat it, and close them during the night or on cloudy days
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Close doors to rooms that are not being used
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For A/C units on the ground, make sure they are free of debris
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Do not turn off your A/C in the hot months when you’re not home. It will most likely take more power to restore your home to a desirable temperature because the home has been accumulating heat all day.
My HVAC Usage
There are two A/C units, one for downstairs and one for up. I keep the filters clean by rinsing the reusable air filters every month. Also, there is a service contract where a company comes out and does a 50 point maintenance before summer and winter.
My Variable(s):
- Each unit has a programmable thermometer
Next I’ll look at lighting, appliances and other devices.
Sources:
http://www.ornl.gov/sci/roofs+walls/insulation/ Oakridge National Laboratory
http://en.wikipedia.org/wiki/Radiant_barrier – Wikipedia
http://www.nevadapower.com – Nevada Power