03-13-16, 03:49 PM | #11 | |
Less usage=Cheaper bills
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Quote:
Granted, it is still an unwanted air exchange and I'd prefer it be sourced from the outside too, but it isn't as much air as you are implying. |
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The Following User Says Thank You to MN Renovator For This Useful Post: | Servicetech (03-15-16) |
03-15-16, 06:40 AM | #12 |
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100k furnace would run 1/3 of the time on a design day, mush less on a normal day. Look at Therms burned in a month to get a better look at actual run time.
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03-15-16, 09:33 AM | #13 |
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Thanks, if I can get to 85% and getting to theoretical maximum I'd be happy. Materials and time invested would be minimal compared to time and investment to replace with 95%. Someone using propane or oil might see a better return. I guess I'll know if I over achieve and it starts condensing. Unfortunately yesterdays high was 92f, winters been over for a month already.
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03-15-16, 07:06 PM | #14 |
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To hit 85% you have to get the air/fuel ratio exactly right. At 83% you start having condensation problems. You’re talking about modifications to get THREE PERCENT. In TEXAS you will NEVER see the difference in your gas bill. Is 92f already, you use the heat 3 times a year?
We went from an 88k 80% to a 44k 90% in Oklahoma, didn't see any real world difference in gas bills. Cutting the furnace size in HALF did make a HUGE difference in comfort, no more wide temp swings between cycles. Your efforts are much better spent on improving AC efficiency, there’s a LOT more on the line. REAL MONEY.... Looking at your signature you have really tightened up the house, when it comes time to replace the AC install HALF the typical 500sqft per ton. 1,000sqft per ton may sound nuts for TX, but does your house not have about 1/2 the typical heat gain for your area? |
The Following User Says Thank You to Servicetech For This Useful Post: | jeff5may (03-15-16) |
03-16-16, 09:18 AM | #15 |
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Its not one 100k furnace its 2x 50k units, the match up for their 2 ton a/c counterparts. I get about 15 seer out of the a/c units and don't plan on replacing them too soon. 600 sqft per ton is about the max I care to go, we still have 100F weeks. I prefer to have the hvac off when the house is unoccupied and require more btu to catch up when we get home. Additionally my wife is requiring the house cooler as we age. We used to get by with 78f indoor, last year that went down to 76f, this year shes complaining about 74f. The good news is with my improvements our power usage still went down, thanks micro solar. I know this won't effect my gas bill by much, its more of a curiosity. Preheating the air makes sense, mixing burning 100f air vs 60f air should yield a more heat.
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