Define "normal home" in the fuel cost calculator pls.

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Bster13

Minister of Fire
Feb 24, 2012
810
CT
As you note, there is a lot of variation from home to home....that link is to allow you to estimate the relative cost of a million BTU for different fuels and efficiencies, not the total annual cost for a home.

For a rough estimate, the number of BTUs you need to deliver to a house is given by HHI*sqft*HDD, where HHI is the home heating index in BTU/sqft*degree_day.

Typical HHIs for existing US houses are in the 7-12 range. SO, if you know the heating degree days/season and the sq footage, you can estimate (a range) of BTU requirements/year.

If you know the fuel and the age of the equipment, the link you site will tell you the cost of heating for a year.

If it is new construction, you might be more like 5-8 for HHI. An old victorian might be >12. If it is a (skilled) green builder selling energy-star homes, it might be 3-5.

EDIT: looks like the tool assumes the US average heating load: ~90 Million BTU/yr. do the above calc for your case ^^
 
This is me:

http://www.huduser.org/portal/resources/UtilityModel/source/hdd_data.odb?INPUTNAME=926+2.9579825417E-4*NORWALK+GAS+PLANT&stname;=$statename$&stusps=CT&zip_code=06850&year=2007
 
That link was broken for me, but it looks like Norwalk has 5500 heating degree days, HDD. An average sized (2200 sq ft) house, new construction (HHI = 5) would require

5*2200*5500 would require 60 million BTUs to heat for a year. An older, not very well weatherized house of the same size could easily require twice that much.

Is this new construction? What fuel or heating system?
 
I interpret the map as Norwalk having 6000 heating days so...

Trying to be conservative...

7*1432*6000 = 60144000, so roughly the same.


I wonder how much coal that translates to.

Many thanks for walking me though things!

woodgeek said:
That link was broken for me, but it looks like Norwalk has 5500 heating degree days, HDD. An average sized (2200 sq ft) house, new construction (HHI = 5) would require

5*2200*5500 would require 60 million BTUs to heat for a year. An older, not very well weatherized house of the same size could easily require twice that much.

Is this new construction? What fuel or heating system?
 
1 MMBTU = 9-10 gallons of oil...so the estimate comes in ~600 gal/yr, or ~$2400/yr

Built in 1955 (before universal insulation) demand is esp difficult to estimate. As built, that house might have used >1000 gallons oil per year. If it has been retrofitted well, it might use only half that now. Impossible to say--ask the current owners.
 
137,000 - 141,800 BTU per gallon of heating oil according to this website:
http://www.engineeringtoolbox.com/fuel-oil-combustion-values-d_509.html

So 60144000 BTUs per year / 141,800 = 425 gallons of heating oil (giving the oil's BTU the benefit of the doubt) or $1551.25 ($3.65 / gallon currently).

And these are prices today....they will go up....and does not include maintenance on the oil burner (I grew up with gas as a kid....no clue what maintenance is yearly on oil burner).
 
Bster13 said:
137,000 - 141,800 BTU per gallon of heating oil according to this website:
http://www.engineeringtoolbox.com/fuel-oil-combustion-values-d_509.html

So 60144000 BTUs per year / 141,800 = 425 gallons of heating oil (giving the oil's BTU the benefit of the doubt) or $1551.25 ($3.65 / gallon currently).

And these are prices today....they will go up....and does not include maintenance on the oil burner (I grew up with gas as a kid....no clue what maintenance is yearly on oil burner).

Typical oil equipment has stated eff of ~82%, and actual eff due to cycling can be much lower, esp if oversized, as is common. Unless it a condensing, cold start system, you are likely only going to get 105-110,000 BTU/gal.

I also would consider the 60 MMBTU to be a lower bound on a 1955 ranch house. If it has never been properly airsealed, it might need 100 MBTU, and then you are talking 900 gallons or twice your estimate. OF course, in that case, you could get an energy audit and some professional help, and should be able to drop your demand to <60 MBTU without a huge investment (a few $k).

Maintenance and service plans seem to have gone up since oil became dear....I would assume $200+/yr for an annual cleaning and emergency service plan.

A lot of folks have come to wood heating recently due to the cost of oil. You can see why.
 
Ok, next house! (I owe you a beer :p)

Same town, same style house and time era (1 flr ranch, but unfinished basement this time), 1974 sq ft:
http://www.zillow.com/homedetails/5-Beauford-Rd-Norwalk-CT-06854/58816390_zpid/

But this house has a brand new (8/4/2011) gas furnace and water heater. (yeah for gas!)

7*1974*6000 = 82908000 BTUs in a year.

Natural gas is measured in Therms (100,000 BTUs), so...

82908000 / 100000 = 829.08 terms @ $1.43 = $1185.59 per year in heating costs.

If I switched to Anthracite Coal @ 25,000,000 BTU / Ton....

1st house w/ oil:
60144000 BTUs per year / 141,800 = 425 gallons of heating oil (giving the oil’s BTU the benefit of the doubt) or $1551.25 ($3.65 / gallon currently).
or
7*1432*6000 = 60144000 BTU per year / 25000000 = 2.41 tons of coal per year or $743.35 (costs me $1110.4 to 3.6 ton delivered)

2nd house w/ natural gas:
82908000 / 100000 = 829.08 terms @ $1.43 = $1185.59 per year in heating costs.
or
7*1974*6000 = 82908000 BTU per year / 25000000 = 3.32 tons of coal per year or $1024.04 (costs me $1110.4 to 3.6 ton delivered)

Provided I stay in one of these homes for the next 30 years...

It does not make sense to switch to coal in the Natural Gas house at today's prices. It would make sense in the oil burning house. Now if what you are saying about ~real~ BTUs of a furnace w/ inefficiencies and a somewhat drafty house, the gas house may make sense to switch to coal, but that does not take into consideration the cost of a new coal stove, chimney stuff and install costs.
 
Ok. I still think your absolute numbers are skewed too low/cheap/optimistic, due to the eff issues, and are v uncertain regarding the unknown current condition of these older houses.

Still, your numbers are probably in line with what you might get if you were willing to shell out a few grand in energy audit/retrofitting....both houses could probably get down to HHI 5-6 regardless of their current condition, with decent ROI for the retrofit work.

On the relative price of oil, gas and coal...you can work from quoted rates for the local utilities. I would kill to have a gas line, but the main ends at my neighbors house (and I was quoted $20k to extend it).
You should def included estimates for equipment efficiency in your calcs...as is done in the fuel cost link we started with.

I agree with your conclusion that few folks with natural gas would ever burn coal, but that some folks burning oil might, to save some money. The previous owner of my house did, along with a number of other decisions that seem dubious to me now.
 
Bster13 said:
Hrmmm...this guy can heat 2300 sq ft home w/ a hand fed stove and blowers. Interesting.

http://www.youtube.com/watch?v=DyazzUvr7Do

I heat my 2000 sqft home with a hand fed stove and 2 blowers. I even have major issues with cold air intrusion. (It's going to be a busy spring/summer with lots of construction)

I've also gone through almost 10 cords of questionable quality wood doing so.

I did the math for our place, and I would be going through almost $1600/month in oil if I were to go that route (the previous owners were able to use a natural gas heat stove, hence keeping their oil cost down. I don't have the free gas). I don't have $1600 to throw away a month, so it isn't an option either. I do work for a local maple producer who lets me keep the trimmings and the tops when we do clearing.

Wow, you guys are fast... Don't forget that the costs of oil are fluctuating wildly now and that gas is at a historic low... It might take alot of wood, but if you can get the wood cheaper and enjoy it it works out ok!
 
Another wrinkle...

House #1 w/ oil:
Furnace is from 1998. Efficiency rating on the side of it is 84.6%.

House #2 w/ gas:
Furnace is from 2011 (so is water heater). Efficiency rating on the side of it is 80.6%.

Is that weird? I thought Gas furnaces were inherently more efficient.

Another thing I did not consider.... the gas company charges a $15 / month whether u don't use the gas or not in the summer.
 
Redoing some calculations for less efficient home:


If I switched to Anthracite Coal @ 25,000,000 BTU / Ton….

1st house w/ oil:
77328000 BTUs per year / 141,800 = 536 gallons of heating oil (giving the oil’s BTU the benefit of the doubt) or $1956.40 ($3.65 / gallon currently).
or
9*1432*6000 =77328000 BTU per year / 25000000 = 3.10 tons of coal per year or $956.18 (costs me $1110.4 to 3.6 ton delivered)

2nd house w/ natural gas:
106596000 / 100000 = 1065.96 terms @ $1.43 = $1524.3228 per year in heating costs.
or
9*1974*6000 = 106596000 BTU per year / 25000000 = 4.27 tons of coal per year or $1317.05 (costs me $1110.4 to 3.6 ton delivered)
 
I think the only real way to get a good estimate is to see the previous owners usage and ask them how warm they kept the house. I never really thought about heating costs until this house as it is the first one without natural gas. The previous owners put 4000 gallons of lp in the tank the year before we bought it and when we looked it the house was mid 60s. LP was $4.25/gallon. There was a wood stove in the middle of the house before that first winter and I have spent a lot of time and money since tightening up the shell. This year it looks like I am going to burn 5 or 6 cord. Burned 12 the first couple winters.
 
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