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Energy Engineering

BTU Conversion Factors
Electricity Natural Gas* Fuel Oil Propane Purchased Steam	3,412 BTU / kWh 92,000 BTU / CCF 138,700 BTU / gal 91,600 BTU / gal 933 BTU / lb

*   Heat value of natural gas varies so there is a conversion
    factor applied the the LDC. The BTU per CCF varies from
      85,000 to 105,000 BTU / CCF     (10X for MCF)

* Therm       =     100,000   BTUs
* Dth          =   1,000,000   BTUs

Energy conversion charts

This page offers a quick reference for energy conversion measures.

1 cubic foot of natural gas         =     1,000 BTU
1 pound of coal                         = 12,000 BTU
1 gallon of propane                   =    91,600 BTU
1 gallon of gasoline                   = 125,000 BTU
1 gallon of fuel oil #2                 = 139,000 BTU
1 gallon of fuel oil #6                = 150,000 BTU
1 kilowatt hour of electricity     =      3,412 BTU

	1 Million BTU	24 Million BTU	91,600 BTU	125,000 BTU	139,000 BTU	150,000 BTU	3,412 BTU
Natural Gas cu. ft.	1,000 cu. ft.	24,000 cu. ft.	91.6 cu. ft.	125 cu. ft.	139 cu. ft.	150 cu. ft.	3.412 cu. ft.
Coal lb.	83.33 lb.	2,000 lb.	7.633 lb.	10.417 lb.	11.583 lb.	12.5 lb.	0.2843 lb.
Propane gal.	10.917 gal.	262 gal.	1 gal.	1.365 gal.	1.517 gal.	1.638 gal.	0.0372 gal.
Gasoline gal.	8 gal.	192 gal.	0.733 gal.	1 gal.	1.112 gal.	1.2 gal.	0.0273 gal.
Fuel Oil #2 gal.	7.194 gal.	172.662 gal.	0.659 gal.	0.899 gal.	1 gal.	1.079 gal.	0.0245 gal.
Fuel Oil #6 gal.	6.667 gal.	160 gal.	0.611 gal.	0.833 gal.	0.927 gal.	1 gal.	0.0227 gal.
Electricity kWh	293.083 kWh	7,034 kWh	26.846 kWh	36.635 kWh	40.739 kWh	43.962 kWh	1 kWh

1 kWh =                                                        10,000 BTU =
                 3412.14 BTU                                                   2.93 kWh
                    3.41    kBTU                                                 0.088 Gasoline gallons
                    0.003 MBTU                                                 0.077 Diesel gallons
                    0.03 Gasoline gallons                                   0.109 Propane gallons
                    0.026 Diesel gallons                                     0.074    Kerosene gallons
                    0.037 Propane gallons
                    0.025 Kerosene gallons

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Energy Cost Per BTU - Calculations

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Benchmarking:

BTUs Per Square Foot for various classes of buildings

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LIGHTING GLOSSARY

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HVAC GLOSSARY

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Electrical Engineering - Introduction

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INSULATION

Wall Assembly R-Value

Component	R-value
Wall - Outside Air Film	0.17
Siding - Wood Bevel	0.80
Plywood Sheathing - 1/2"	0.63
3 1/2" Fiberglass Batt	11.00
1/2" Drywall	0.45
Inside Air Film	0.68
Total Wall Assembly R-Value	13.73

R-Value Table

Material	R/ Inch	R/ Thickness
Insulation Materials
Fiberglass Batt	3.14
Fiberglass Blown (attic)	2.20
Fiberglass Blown (wall)	3.20
Rock Wool Batt	3.14
Rock Wool Blown (attic)	3.10
Rock Wool Blown (wall)	3.03
Cellulose Blown (attic)	3.13
Cellulose Blown (wall)	3.70
Vermiculite	2.13
Autoclaved Aerated Concrete	3.90
Urea Terpolymer Foam	4.48
Rigid Fiberglass (> 4lb/ft3)	4.00
Expanded Polystyrene (beadboard)	4.00
Extruded Polystyrene	5.00
Polyurethane (foamed-in-place)	6.25
Polyisocyanurate (foil-faced)	7.20
Construction Materials
Concrete Block 4"		0.80
Concrete Block 8"		1.11
Concrete Block 12"		1.28
Brick 4" common		0.80
Brick 4" face		0.44
Poured Concrete	0.08
Soft Wood Lumber	1.25
2" nominal (1 1/2")		1.88
2x4 (3 1/2")		4.38
2x6 (5 1/2")		6.88
Cedar Logs and Lumber	1.33
Sheathing Materials
Plywood	1.25
1/4"		0.31
3/8"		0.47
1/2"		0.63
5/8"		0.77
3/4"		0.94
Fiberboard	2.64
1/2"		1.32
25/32"		2.06
Fiberglass (3/4")		3.00
(1")		4.00
(1 1/2")		6.00
Extruded Polystyrene (3/4")		3.75
(1")		5.00
(1 1/2")		7.50
Foil-faced Polyisocyanurate (3/4")		5.40
(1")		7.20
(1 1/2")		10.80
Siding Materials
Hardboard (1/2")		0.34
Plywood (5/8")		0.77
(3/4")		0.93
Wood Bevel Lapped		0.80
Aluminum, Steel, Vinyl (hollow backed)		0.61
(w/ 1/2" Insulating board)		1.80
Brick 4"		0.44

Interior Finish Materials
Gypsum Board (drywall 1/2")		0.45
(5/8")		0.56
Paneling (3/8")		0.47
Flooring Materials
Plywood	1.25
(3/4")		0.93
Particle Board (underlayment)	1.31
(5/8")		0.82
Hardwood Flooring	0.91
(3/4")		0.68
Tile, Linoleum		0.05
Carpet (fibrous pad)		2.08
(rubber pad)		1.23
Roofing Materials
Asphalt Shingles		0.44
Wood Shingles		0.97
Windows
Single Glass		0.91
w/storm		2.00
Double insulating glass (3/16") air space		1.61
(1/4" air space)		1.69
(1/2" air space)		2.04
(3/4" air space)		2.38
(1/2" w/ Low-E 0.20)		3.13
(w/ suspended film)		2.77
(w/ 2 suspended films)		3.85
(w/ suspended film and low-E)		4.05
Triple insulating glass (1/4" air spaces)		2.56
(1/2" air spaces)		3.23
Addition for tight fitting drapes or shades, or closed blinds		0.29
Doors
Wood Hollow Core Flush (1 3/4")		2.17
Solid Core Flush (1 3/4")		3.03
Solid Core Flush (2 1/4")		3.70
Panel Door w/ 7/16" Panels (1 3/4")		1.85
Storm Door (wood 50% glass)		1.25
(metal)		1.00
Metal Insulating (2" w/ urethane)		15.00
Air Films
Interior Ceiling		0.61
Interior Wall		0.68
Exterior		0.17
Air Spaces
1/2" to 4" approximately		1.00

Air Infiltration Estimation Table

Home Condition	ACPH*
Existing Home
Old very leaky home	1.00
Old moderately leaky home	.75
Average home	.50
Fairly tight home	.45
Tightened Home
Average Tightening to Old Very Leaky Home	.75
Average Tightening of Old Moderately Leaky Home	.60
Average Tightening to Average Home	.45
Blower Door Assisted Professional Sealing Job (This is what E-Star certified energy raters do.)	.35
Blower Door Assisted Professional Extreme Tightening (E-Star certified energy raters can do this.)	.25 **
* Air Changes Per Hour is the amount of air inside your home that is replaced by outside air every hour. ** You probably don't want to lower your ACPH below .35 ACPH without adding a mechanical ventilation system to your home to bring in enough fresh air to maintain a healthy living environment. It is difficult to get your house to this level without professional help.

Heating System Efficiency Table

The following table will give you a rough idea of your current heating system efficiency. The better the condition and the more preventive maintenance it has had, the higher the efficiency:

Heating System Type	Efficiency
Natural Gas, Propane and Oil Furnaces & Boilers
30 years +	.50-.60
15-30 years	.60-.65
10-15 years	.65-.70
Newer Boiler	.75-.80
Newer Induced Draft Furnace (has fan to blow exhaust up the chimney)	.78-82
Newer Sealed Combustion (usually has a PVC air intake and exhaust) High Efficiency Boiler	.85-.92
Newer Sealed Combustion (usually has a PVC air intake and exhaust) High Efficiency Furnace	.90-.97
Electric Resistance
Baseboard, Electric Furnace, Ceiling Radiant	1.0
Heat Pumps
Older Air-to-Air	1.5-1.8
Newer Air-to-Air	2.0-2.2
Water (Ground) Source	2.8-3.2

Air Conditioner

SEER Value Table

The following table will give you a rough idea of your current air conditioner SEER value:

Age and Condition	SEER
20 years old - Not well maintained	6.0
20 years old - Well maintained	6.5
10-20 years old - Not well maintained	7.0
10-20 years old - Well maintained	8.0
5-10 years old - Not well maintained	7.5
5-10 years old - Well maintained	8.5
Less than 5 years old	9.0
Base AC units put in today	10.0
High Efficiency Unit *	14.0

* New standard is SEER 13. Some mini split A/C claim SEER of 22

Window/Door Air Leakage Table

The following table will give you a rough idea of your window/door leakage rate

Window Quality	cfm/ft
Loose Fit - No Weatherstripping	1.01
Average Fit - No Weatherstripping	0.35
Average Fit - With Weatherstripping	0.18

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