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#1 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
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![]() Colder = more money for heat! 24 kWh daily!
Last 7 Days Weather: , It got warm on the 28th, but lately, it's been pretty cool around here. Starting last cycle (Dec 23) were are being billed at 16.18 cents per kWh. With the extra heating for the Den, we are burning about 24 kWh daily. A continuous 1kw per hour on average, or $3.88 per day. That seems really high compared to previous years running one Sanyo, (instead of two). But, $3.88 is about what it would cost for one gallon of heating oil.. Without the Sanyos. I'm pretty sure we would be using 3 to 4 gallons a day for heating, If we decided we really liked keeping the whole house at 21C all day.. Last month, we were using 20C during sleeping hours, but recently it started feeling a bit too warm. So this month we've been setting back to 19C. It takes a little longer to get back up to 21C, but I'm finding it's not all that bad to get up at 8AM to a house that's almost 20C.. ![]() My forecast for January is 20 to 30 kWh per day. We hope the new 2012 NStar rates aren't going to increase too much. It would be great if they lowered them again!
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#2 |
Less usage=Cheaper bills
Join Date: Nov 2010
Location: Minneapolis, MN
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![]() November's natural gas bill was just a hair under $20
I don't have the December bill but the furnace ran for 32h13m which is 24 therms, plus about 8 for the hot water tank and I'm figuring about 32 therms at about 68 cents per therm plus fees and taxes for a rough $33 expected bill. ...and my energy auditor gave me funny looks when he saw my gas bill was about $70 last December. More efficient house than last December, sure. I give more credit to the increased sunlight and much higher temperatures than usual in Minnesota this winter. |
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#3 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
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![]() For sure you've done a good job with insulation & sealing!
The cost for gas heating seems very reasonable around here, but they never laid the pipes in this neighborhood. For the most part, my neighbors are all dependent on fuel oil for heating and DHW. Even with the mild weather, they are getting hit hard in the wallet. Yeah, you should make an effort to exploit solar space heating as much as possible. Looking for the right size glass, while you build the collector(s) seems like a good idea. In the interim, you could just use plastic sheet. Like the heavy duty 48"x25' stuff I found at Home Depot. 48 in. x 25 ft. Clear Plastic Window Installation Kit-V4825/4 at The Home Depot http://ecorenovator.org/forum/conser...html#post16999 It's pretty good stuff and might last a few years outdoors.. But it likely require a very steep mounting angle, to let the snow slide off..
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My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. |
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#4 |
Less usage=Cheaper bills
Join Date: Nov 2010
Location: Minneapolis, MN
Posts: 939
Thanks: 41
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![]() The snow will melt off quickly if any sun manages to get through if I'm using plastic and even enough to do some work if I'm using glass since a decent amount of heat will pass through and melt it. Snow even manages to melt off the double pane skylight in the bathroom as enough heat passes through the skylight. Having something black an inch away will leave me clearing most heavy snowfalls off the glass but most lighter stuff will likely melt off. Plastic, even if its heavy might not stand the snow load. I'll wait until I can get some glass as the table saw that I have access to use is stored in a shed and it will unfortunately be a summer project for me. This winter hasn't been too cold yet so I'm not too missing out too much unless January is worse than last year.
I did some calculations on what the solar heat collection would be for a black 4x8 surface. I'm not believing the results though or that would have likely amounted to more heat than my furnace has produced so far this heating season. If that were the case I'd have excess heat but I think my math is wrong. I was at a 'Living Green' expo and talked to a guy there that told me that the amount of heat lost out of glass, even if double or triple paned and well sealed makes the glass cost more than the solar energy than they allow through in Minnesota in December and January for the temperatures we get. Low SHGC on southern windows makes it worse as it blocks the sunlight that we need here. He said that anyone in MN with double pane glass with good condition glass shouldn't replace their current south facing windows with 'tax credit/energy star' glass as the cost to heat the house will go up more than it will cost cooling the house is there is a decent overhang or if the owner installs an awning or deciduous shade. I'm thinking that if a house built with smaller windows or low SHGC that glass outside the house would bypass this and allow for solar heating without having essentially an R2 glass assembly installed into a wall. With thermal mass, this all changes a bit because the heat during the day from a large glass assembly is absorbed and stays with the house which is why it works better to have more glass(almost all southern facing) in a passive house. Last edited by MN Renovator; 01-01-12 at 12:55 PM.. |
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#5 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
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![]() Yeah, I agree. The losses via windows and sliding patio doors is massive at our house.
My Den has over 100 sq feet of glass.. And, it's on the north side of the house.. ![]() But, we are heating it this year. (Plus heating the whole house to 70). I'm not sure, but I think if it really gets cold this year, we will be burning about twice as many kW hours as last year..(When we didn't heat the Den much). The whole idea of using outdoor solar hot-air collectors, in place of regular windows for solar gain is excellent. If we had it to do over again, our den would not have a big glass patio slider and we would NOT have four big 48x48" Andersen sliding windows.. That design must have come from way down south.. ![]() I would love to replace that back slider with a regular entry door. Plus replace at least two of the Andersens with insulated walls.. ![]()
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My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. |
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#6 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
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![]() Wow, today we had some snow and it was cold..
We used 33 kWh during the last in 23 hours.. From 00:00 to 07:00, the Sanyos were set for 20C. After that, 21C.. But, it was cold!! High 20.3 °F Low 14.4 °F Average 18.1 °F The Historical average is 34 °F , with a Low of 16 °F.. Woburn, MA 01801 Month Weather Report - AccuWeather.com That's 16 °F below average.. ![]() It just dropped to 14 °F, so I'll be setting up some space heaters to take some of the load, in case it gets below 5 or 6 °F.. ![]()
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My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. |
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#7 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
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![]() I awoke at 6AM and watched those single digits slowly drifting downwards. Clicked the Sanyos down from 20 to 19C, just to be safe. It got down to 6.9°F and the house was still 19 to 20C. Once it started back up (sun came up at 7:08 AM) I started cranking the heat back up towards 21C.. It's going to top out around 29F today, so it looks like another good day for NStar.. ![]() (And the oil companies)! Anyways, the good news is, no back-up was needed last night. The house stayed at the selected setpoints just fine.. During the last 9 hours (since midnight), we've burned up 15.6 kWh ($2.52). Not too bad considering how cold it was. (since midnight). High 16.2 °F Low 6.9 °F Ave 11.7 °F Climatological Data
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#8 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
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![]() And, it's going up into the 50s F again today!!
7 days in January: But, looking back at the record, it was about this warm in Jan 2006, 2007 & 2008.. ![]() Climatological Data Maybe I just remember it being colder, since we didn't have modern electric heat back then.. ![]()
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My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. |
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#9 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
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![]() The average temp during the last 22.6 hours was 25.6 °F, and we burned up 22.8 kWh.($3.71). It's been a pretty weird winter so far. Since 12-1-2011, the average temp has been 34.2 °F.. Still a bit over 5 degs above historic. It's cold tonight, but the good news is the forecast.. Woburn, MA 01801 Month Weather Report - AccuWeather.com It's going up to 51 F tomorrow. And for the next couple of weeks, the highs are going to be 5 to 10 degrees above the historical averages.. ![]() Sadly, in Europe they are suffering.. Heaviest snowfall in decades wreaks havoc across Europe | Weather | guardian.co.uk
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My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. |
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#10 |
You Ain't Me
Join Date: Nov 2009
Location: Northampton MA
Posts: 662
Thanks: 6
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![]() I've been barely using any heat this winter. Today it was int he 50's here and very sunny. It's after sunset now and I just was outside with just a long sleeved shirt on. Earlier I was wearing a t-shirt. It's like March and has been all winter.
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