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Old 04-06-11, 08:21 PM   #4
MN Renovator
Less usage=Cheaper bills
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Join Date: Nov 2010
Location: Minneapolis, MN
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I think the refrigerator is actually using the most in my house right now. In the summer its the air conditioner. The furnace didn't run that much.

I used 76 therms in January $67 total, which includes the $10.50 for fixed service fees.
I used 206 kWh for 34 days from the middle of December to the middle of Jan $34.
I used 131 kWh for 29 days from the middle of February to the middle of March $27.

About 75 kWh where most of it was the furnace. If it was pulling 6 amps for the roughly 110 hours it ran from the middle of December to middle of January, it comes to about 80kWh, so I think that is about right. I still think the refrigerator might have done more of the dirty deed than that but 80kWh is still a significant portion of the bill.

I'm not sure I have much to complain about with almost $10 in electricity in the winter, its the summer chunk that it pulls since the blower runs at high speed, which oddly enough doesn't seem to draw all that much more power. I pulled the tap from tap 1(highest) to tap 4(lowest) and the difference wasn't even an amp less. Furnace is tap 3 and AC(2 ton, needs 800CFM) is tap 1. I did some research on permanent split capacitor and shaded pole motors, it seems it doesn't matter which speed they run, they draw roughly the same power.

Good to know that I'm pulling similar power as other people are, I thought this was nuts when I first saw it but I'm still a little confused why a 1/6HP motor is pulling so much amperage. I figured a 1/6 HP motor might be pulling a little less than its rating and would burn up pulling 6 times the electric power than what the HP rating would lead me to think.

The filter is a pleated filter and isn't too restrictive, not hard to see light through it. When I did the test the filter wouldn't affect it since the whole blower door is off so its getting an easier time since its not sucking air from the return ductwork since it has an easy path through the front and the ducts are going to be clean on the supply end since the filter keeps that side clean.

I think the ECM or X10 or other BLDC type variable speed blowers are the key to energy efficiency and cut the cost of operating a furnace tremendously. Whenever a major expensive component of my current HVAC setup fails, my next furnace and air conditioning setup will have one of these efficient blowers for sure. With my insulation efforts that will be going on soon(upcoming thread) and the air sealing I did at the beginning and throughout this winter, my heating and cooling needs will be reduced, hopefully with some significance as I'm thinking going from 7-9" of cellulose in the attic to R60 and filling in various insulation voids I've tracked down and some other issues I've found preventing insulation from doing its job in a few places I think I can cut my energy use even more.

The problem is that buying more efficient equipment suddenly becomes financially stupid because I reduce my costs so much to the point where I don't see how I could possibly recuperate the money spent. I've got a 2200 sq ft house that I spent a under $70 in gas to heat for December and January each and under $70 electric bill in July when air conditioning. I just don't see how spending so much on equipment is going to save all that much money once I've insulated and cut these costs down more. I'm not ranting, I hope its not coming across this way, I'm just trying to figure it out because if my equipment fails, going from a 76% efficient to a 95% efficient furnace and a variable speed blower would be great to know that I'm getting 15% more heat from the natural gas over an 80% and a 16 SEER versus a 13 SEER to replace my current 10-12 or so. Do they make 80% efficient furnaces that pull in outside air like the 90%+ furnaces do? I'd prefer one that pulls in outside air and it would pull me towards a 90+ really quick if forced infiltration isn't required for combustion air. It all seems great but the savings seem to be there for the inefficient house. Has anyone else had this thought process?
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