Oil Consumption

dnme

I'm renting a cottage that appears to be well insulated. It is dry lined but the dry lining has the 1/2" insulation on the back of it. The attic is also well lined. I run the oil for just 1/2 hour every evening just to keep the place tickin over. Apart from that I have a small solid fuel stove in the living room. I put 300L of oil in the tank at the start of February (5/2/12) and ran out last weekend (5/5/12). So 300L lasted me three months. I was disappointed with that but am I right to be?

By my calculations, for 1/2 hour of burn, I was using 3.3 litres per day. This seems like an awful lot. Its equivalent to burning an entire bale of briquettes every day just to heat the rads and hot water for 1/2 hour. Doesn't that seem very inefficient?

Billy Bunting

dnme wrote: »

By my calculations, for 1/2 hour of burn, I was using 3.3 litres per day. This seems like an awful lot. Its equivalent to burning an entire bale of briquettes every day just to heat the rads and hot water for 1/2 hour. Doesn't that seem very inefficient?

Your calculation sound about right, unfortunetly the price of fuel these days does make it sound inefficient.

dnme

Billy Bunting wrote: »

Your calculation sound about right, unfortunetly the price of fuel these days does make it sound inefficient.

So Billy, do you reckon my rate of burn is normal? (3L for a half hour) ?

Billy Bunting

Sounds on the higher side of normal for a small cottage but all depends on boiler, nozzle size and oil pump pressure, when was it last serviced and how was it commisioned.

dnme

Billy Bunting wrote: »

Sounds on the higher side of normal for a small cottage but all depends on boiler, nozzle size and oil pump pressure, when was it last serviced and how was it commisioned.

No idea

shane0007

dnme wrote: »

So Billy, do you reckon my rate of burn is normal? (3L for a half hour) ?

This is extremely high for 1/2 hour of usage.

If your boiler is a 50/90, it will probably have a 0.65 USGal nozzle installed. This will be taken at 7bar pressure, it will use 0.65 US Gallons per hour on continuous usage. This equates to 2.46 litres or 1.23 litres for a 1/2 hour usage.

If the boiler is a 90/120, it will probably have a 0.85 USGal nozzle. This again is taken at 7 bar pressure, it will use 3.22 litres per hour or 1.61 litres for a 1/2 hour usage.

These are both assuming the burner does not switch off at all during the hour and the oil pump pressure is set to 7 bar. For each 0.1 bar pressure add 14% extra consumption per hour.

JohnnieK

shane0007 wrote: »

This is extremely high for 1/2 hour of usage.

If your boiler is a 50/90, it will probably have a 0.65 USGal nozzle installed. This will be taken at 7bar pressure, it will use 0.65 US Gallons per hour on continuous usage. This equates to 2.46 litres or 1.23 litres for a 1/2 hour usage.

If the boiler is a 90/120, it will probably have a 0.85 USGal nozzle. This again is taken at 7 bar pressure, it will use 3.22 litres per hour or 1.61 litres for a 1/2 hour usage.

These are both assuming the burner does not switch off at all during the hour and the oil pump pressure is set to 7 bar. For each 0.1 bar pressure add 14% extra consumption per hour.

I thought Kero was supposed to be 8 bar?

Billy Bunting

The 7 bar Shane refers to is the pressure the manufacturer tests the nozzle at to state its yield us/gallons per hr.

shane0007

Billy Bunting wrote: »

The 7 bar Shane refers to is the pressure the manufacturer tests the nozzle at to state its yield us/gallons per hr.

Absolutely correct. This is the volume of fuel that will pass through the nozzle at 7 bar pressure.

Kerosene pressures will vary from boiler to boiler, depending on the power output required and partilcular design of the boiler. This is tested and set by the boiler manufacturer in conjunction with the burner manufacturer.

Generally, kerosene (28 sec oil) can be anywhere between 7 bar and 10 bar, whilst gas oil (35 sec oil) can be anywhere between 12 and 15 bar, usually.