Thermal loading.....

[DC3]

Don't just go by the dollars. Rates and fuel costs for power companies can change monthly. Compare the actual energy consumption (kWh).

Another thing you can do to factor out changing weather from month to month is to visit the National Weather Service website for your location. Somewhere in their climate data charts should be data for "degree days". Basically a degree day is a way to account for heating and cooling needs based on the average temperature of the day and how far that average temperature is from 65 degrees. If the average temperature is above 65 degrees, it is called a "cooling degree day" (CDD) and if the average temperature is below 65 degrees, it is called a "heating degree day" (HDD). For example, if the average temperature for the day is 85 degrees, there are 20 cooling degrees in that day. And if the average temperature for the day is only 55 degrees, there are 10 heating degrees in that day. The National Weather Service site should have the degree days by each day. You can add up the numbers for each day of your electric bill and then compare month to month to see how cooling needs have changed for your location. If the cooling degree day total goes up 20% from one month to the next, you can expect about 20% increased air conditioning usage (which may translate to less than 20% of the total bill because of lights, refrigerators and other normal usage).

You might also touch base with your power company as they might already know the degree days associated with your billing period.

I helped a lady recently who had super-insulated her house earlier this summer (late in the spring actually) but was disappointed with the results. It seemed her consumption had not changed any after the first month. I helped her realize that the cooling degree days had increased 50% from her "before" month to her first "after" month so the fact that her consumption was the same was a good indication of the benefit she received from better insulation. As it turns out, her consumption for the summer is way down compared to the summer before with similar degree day totals.

Hope this helps.

DC

 

[010752]

......
just pisses me off this wasn't done 13 years ago, could have saved a easy 50 grand in HVAC costs.....:mobeer:

Didn't I suggest this a couple years ago.....:tomato:

I lucked into a Graco 5000 paint sprayer.
Up to 3000psi and up to 3 spray guns, will handle that roof coating syrup.
Biggest one they made a few years ago, sold for up 5 grand new, got it for 400 bucks. Couldn't turn it down.

Nice part is, roof that took me almost 3 days to do is now down to 1/2 day.

 

[mrvette]

Well, I finally got a utility bill.....

the bill dated last 8/17/10 as worst ever at 2088 kwh....cost me 245 bux....

the bill dated this 9/17/10 is lots better at 1598 kwh cost me 190 bux.....

now the key comparo is Chuck next door, has the same shingles I did the light gray 3 tab junk.....his bill went down only 20 bux from same time frame....

now I have to take the same 20 buck drop for the weather being slightly cooler, so my 55 buck drop is only really 35 due to the roof coating.....

and it's only Chuck/wife there, and to boot, they don't cook, almost always eat out....electric range....

Linda cooks all the time, and we have her mother and aunt here for ten daze every month....figger hot water/food/cooking heat buildup, etc....we have a gas range though, so at least that's not adding to electric....so Chuck/Fe don't cook, call that a even enough break/equalized out....

SO IF I didn't have the house guests...doubling up all the loading....I figger maybe another 20 buck/month savings....

so the roof coating is definitely worth it, no question.....:clap::clap:

I look at it saving a high of 30 bux/month during July/Aug/Sept....maybe 15 for a couple months on each end.....or about 150 bux/year.....

and I still have to put down the second coating just for the color evening out....maybe a few more degrees temp drop....

:banghead::drink: