Non-Residential Solar Information Manual
Section 13 - Useful Data And Formulae

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1 litre water expands to 1.0207 litres through 1000 C temperature rise.

AREA

1 square metre						=	10.764		square feet
1 hectare						=	10,000		square metres
							=	2.47		acres

ENERGY

1 kilojoule						=	0.948		Btu
1 calorie						=	4.187		joules
1 kWh							=	3.6		MJ
							=	1		gas unit
							=	3.33		cubic feet gas
							=	3415		Btu

FLOW

1 Imp GPM						=	4.546		litres/min
							=	0.0758		litres/sec
							=	0.2728		cubic metres
										per hour

HEAT

1 Btu							=	0.2931		Watt-hours
1 therm							=	29.31		kWh
							=	100,000	Btu
							=	105.51		MJ
							=	33472		Btu/h

THERMAL CONDUCTIVITY

1 Btu/h ft 0F						=	1.73		W/m 0k

OVERALL HEAT TRANSFER "U"

1 Btu/h ft2 0F						=	5.678		W/m2 0k

LENGTH

1 metre							=	3.281		ft

MASS

1 tonne				=	1000 KG	=	1000		litres water
							=	2204.6		lbs
1 kg							=	2.205		lbs
							=	1000		gramme
							=	1		litre of water
PRESSURE

1 psi							=	6.895		kPa
1 atmosphere						=	33.96		feet water
							=	760		mm mercury
1 pascal						=	1		newton/m2
							=	1/10		kg/m2

POWER

1 Hp							=	746		Watts

SOLAR RADIATION

1 Cal/cm/day						=	1		langley/day
							=	0.04187	MJ/m2.day
							=	0.0116		kWh/m2.day
							=	3.69		Btu/ft2/day
							=	11.6		Wh/m2.day
1 MJ/m2.day						=	88.09		Btu/ft2/day
							=	1/3.6		kW/m2.day

TORQUE

1 lb ft							=	1.356		Newton metres

VOLUME

1 cub metre						=	35.31		cub ft
							=	1000		litres
							=	219.97		Imp gals
							=	1000		kg of water
							=	1		kilolitre
1 Imp gal						=	1.2		US gal
1 cub ft							=	6.23		Imp gal
I Imp gal						=	4.546		litres
1 part per million					=	1		mg/litre

USEFUL FORMULA

litres of water x º C					=			kilo calories
litres of water x º C x 4.186				=			kilo joules (kJ)
litres of water x º C  x 4.186 / 3600			=			kW
litres of water per hr x 0C x 4.186 / 3600			=			kWh
(kJ)/3600						=			kW
(Watts)/1000						=			kW

CALORIFIC VALUES OF VARIOUS FUELS AND EFFICIENCIES OF APPLIANCES

NATURAL GAS

1 unit gas						=	1		kW
							=	3412		Btu/hr
							=	3.3		cub ft
							=	3.6		MJ
							=	0.038		MJ										=	38		MJ/m3

High efficiency gas water heater				-	80%
Average unit on market					-	75%
Large gas fired boiler o/A efficiency			-	70%
Pilot light gas consumption - average			-	30%
Net calorific value						939		Btu/cub ft dry
Gross calorific value						1040		Btu/cub ft
Storage heat loss					-	20%
Instantaneous heater					-	10%

BOTTLED GAS

45 kg bottle						=	21500		Btu/lb gross
							=	6.17		kW/lb
							=	13.6		kW/kg										=	49		MJ/kg
							=	611		kW/45 bottle (gross)
							=	88.6		litres

APPLIANCE EFFICIENCY

Average appliance O/A efficiency			-	75%
Pilot light consumption					-	30%
Storage heat loss					-	20%
Storage heater to 640 litres					refer AS1056
Instantaneous heater					-	10%

OIL

Distillate

Calorific value						=	18.400		Btu/lb
							=	5.412		kW/lb
							=	11.91		kW/kg
							=	36		MJ/litre
							=	10.0		kW/litre
Specific Gravity (SG)					=	0.84

Appliance efficiency O/A average			-	70%		small heaters
							-	65%		large boilers

BUNKER FUEL

Calorific value						=	1800		Btu/lb gross
							=	5.294		kW/lb
							=	11.65		kW/Kg
							=	10.72		kW/litre
SG							=	0.92
1 barrel oil						=	35		Imp gal
							=	158.98		litre
							=	1590		kW

Appliance efficiency O/A					-	60%		large plants


POWER GENERATION EFFICIENCIES

Diesel Power Station Generator Set
Station Efficiency					-	39 to 40%
Steam Generating Plant Efficiency			-	28 to 30%
Transmission Line Efficiency				-	92 to 93%
Overall Efficiency of Steam
Generating Plant to Water Heater			-	26 to 27%

SOLID FUEL (WOOD)

Combustion Efficiency					-	30%
Calorific Value:
Best Jarrah (12% moisture)				-	7000		Btu/Ib
All timbers release approximately the same amount of energy per unit mass

RING MAIN HEAT LOSSES

Good Quality Well Insulated				-	10%		of total load
Average to Fair Quality					-	20%		of total load
Poor Quality to Poor Insulated				-	50%		of total load