Apperson on Energy- Lessons from Stockton

I've spent the better part of the last two weeks at the PG&E Training Center in Stockton. Whenever a new energy conservation incentive program is about to start PG&E requires the people who will be involved in it to have up-to-date training and guidance in program policy and procedures. During these eight days of enlightenment there were some points that came up that are worth passing on to utility users. So here are a few of the things in this latest training that may be of interest.

For a heating engineer to figure the amount of time a furnace or A/C may be running in a particular area a figure is used called "Heating Degree Days" (HDD) and "Cooling Degree Days" (CDD). These numbers are determined by starting with a "balance point."

For heating, this is 65 degrees and cooling it's 78 degrees. You take the average daily temperature, lets say a low of zero and a high of 30 degrees, average is then 15 degrees, and you subtract that from 65 degrees (the balance point) and you get 50. Fifty is then your HDD for that day and you repeat for every day with an average below 65 degrees. Do the same with the CDD but use 78 as your balance point. We have about 4,000 HDD and 1,000 CDD in our area. Truckee has 8,230 HDD and only 33 CDD. I've always thought of New York, NY as a cold place, but they only have about 800 HDD and 160 CDD more than we do. So NY is only 20 percent cooler than us but it's also warmer than us in summer. I never would have thought New York could be warmer than Ukiah, Must be the humidity.

Some appliance Information

Another item covered was how to save money when your refrigerator isn't full of food. I used to think we should fill old milk jugs with water, which would keep the unit cold when the door was opened. Turns out it costs more to freeze that water in the jugs than you save. However, if you use empty jugs it becomes an energy saver. The reason is those jugs don't keep the inside cooler, they block the cold air from inside the refrigerator from rushing out when the door is opened. Just take empty jugs or anything that holds air and place them along the front edge of each shelf and you'll have a cold air barrier. This then keeps more of that cold air inside the refrigerator instead of allowing it to spill out on the kitchen floor.

Another thing about refrigerators; they work just like a miniature A/C unit, the kind that cools your entire house. This means they compress refrigerant, which generates heat. In your refrigerator the heat is drawn off and allowed to dissipate by circulating through coils along the back of the unit. That means clearance space around the unit is required so the heat has somewhere to go. And those coils on the back of the unit get dust on them which inhibits heat dissipation. You should carefully pull your refrigerator out once a year and clean the cooling coils. Be careful if you have an icemaker, and be careful the feet aren't plowing furrows in your new floor covering.

Now lets look at your clothes dryer. Most folks use the "timed dry" setting to dry clothes. Crank it to 60 minutes and come back in an hour. It's been found that you can reduce your drying cost by 15 percent if you'll use the "more-dry, less-dry" setting. A lot of time the clothes are dry before that 60 minutes are up, so the sensor "more-less" settings shut things down when the clothes are dry. That can really add up, especially if you have an electric dryer, they can easily cost you $10-$30 per month to run.

Temperature and humidity

Next we looked at the comfort inside the home. Two things determine how you feel about the air surrounding you, the temperature and the humidity. Comfortable air temperature for most folks is 65 to 75 degrees which seems rather obvious, with a humidity range of about 30-70 percent. Much above 80 percent humidity and condensation can be an issue, with a dew point forming on windows and just about anything else cold.

There was some interesting information on how that moisture gets into your house air in the first place. The air inside the home is almost always going to be more humid than outside air. In almost every instance where an interior moisture problem is apparent, the root cause is moisture originating from inside the house, not outside -- unless you have a roof leak or similar. Here are some things that put water in the air: a bath or shower can release 1/5 to 1/2 pint, if you happen to have a clothes dryer vented inside the house (or just unvented) it will put 2-3 quarts in the air per load, cooking and then washing the dishes for a for person family frees about a quart and a half of water to become airborne, five to seven house plants put almost one pint of moisture into the air. But the one that really made me think was the entry on the chart that said for every cord of green fire wood you have in the house as much as 100 gallons of water can be released in 6 months. That's like two 55 gallon drums of water that must go somewhere. But what I want to know is where do you hide a cord of green firewood in your house for 6 months waiting for it to dry? This would mean you also have the cord from the previous 6 months that you now are burning. A cord of wood is a stack 4 feet tall, 4 feet wide, and 8 feet long. You can't just hide it under the couch. More next time.
