Boilers operate under the following energy usage principal:
Flue: Energy lost through the flue is typically 20%
System effciency is typically 75%
Therefore the user is only getting back benefit of 60% of the energy cost even though the boiler is rated at say 90% efficient.
Events in an on/off burner cycle:
The boilers thermostat calls for heat due to fall in temperature in boiler. The boilers burner receives power from the boiler thermostat and starts the firing process.
Purge period: The purge period is required at the beginning of every cycle to ensure there is no build up of explosive gases in the boilers chamber. This safety feature is also an energy wasting exercise as cold air is forced into the chamber pushing valuable heat out through the boilers flue.
1st Stage Fire: The 1st stage fire then starts which brings in the lower flame.
2nd Stage Fire: If reqired 2nd stage fire operates which is the hire output flame.
Satisfied: Once the boiler thermostat reaches its set point the boiler thermostat cuts off power to the burner and this is known as one burner cycle.
Back to the purge period:
The intake of air at boiler room temperature in winter say at a few degrees C pushed through the combustion area of the boiler where the temperature is normally between 400⁰C – 1200⁰C (boiler size dependant) causes a drop in the circulating water temperature. The user is paying for an amount of energy used every time the boiler fires because during the purge period water temperature is reduced.
Residual Heat Gain:
Residual heat gain is the extra water temperature above the 80⁰C thermostat setting.
Flue Loss & Wind Suction:
Wind suction through the flue causes a loss of heat in the boiler combustion chamber resulting in more burner firing. Energy consumption increased by 300% in tests carried out.
Q: Does the boiler need to fire as often?
A: No, the boiler is firing to satisfy the heat loss from the boiler chamber and is not firing to satisfy a heating demand from the building.
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Widen the thermostat hysteresis (band width)
1: Wind has less influence
2: Fewer burner fires
2.a: Fewer purge periods
2.b: Longer burner fires
2.c: Better heat transfer
Make the thermostat more intelligent
1: Give it current weather temperature
2: Give it current room temperature
3: Give it burner run time intelligence
4: Give it burner rest time intelligence
Less Fires, Less Heat, NO:
With HeatGEM™ The boiler thermostat stops the burner firing at exactly the same water temperature level …… 80⁰C
But Longer fires create more residual heat after burner firing ….. WHY?
Because a longer fire generates more heat in the confined space of the boiler combustion area and this increases circulating water temperature
HeatGEM™ addresses the following burner inefficiencies
1: Excessive burner fires that are caused by cool air intake
2: Wind suction that causes burner firing unrelated to comfort temperature
3: Multi boiler firing caused by boiler thermostat inaccuracy
How does HeatGEM™ achieve these aims
1: By monitoring weather temperature as input intelligence
2: By monitoring room temperature as input intelligence
3: By monitoring the length of each fire to define demand as current system intelligence
4: By monitoring each burner rest period to define building heat loss intelligence
HeatGEM™ – Addressing Boiler Inefficiency
Most commercial boilers are designed to provide sufficient heat at a weather temperature of -5°C. When the weather temperature is above -5°C, boilers are less efficient and this inefficiency increases in line with a rise in weather temperature.
As the average winter temperature is approximately +8°C this results in boilers operating at sub-optimal efficiency over a full winter period.
The HeatGEM™ device addresses this inefficiency.
Call Acara Energy Today on 01 9022412