Buffer Tank Flows
The use of buffer tanks basically is just add water volume to the heating system.
The use of buffer tanks basically is just add water volume to the heating system. The flow through the tank changes as the flow through the tank changes. The boiler side of the flow in the tank can be constant or variable dependent of the boiler circulator used.
Below is normal piping strategy to add a buffer tank to a high efficiency or cast-iron boiler.
- Oversized boiler
- Micro-zoning
- Zones different heat temperature so not to use mix valve
- Hydraulic separation
A buffer tank will hydraulicly separate the boiler flow from the system flow as these could be much different. Normally the flow through the boiler is consistent and the system flow is variable. Let's see how the flow in the tank can change as system flow changes.
Boiler flow is greater than system flow
This happens when a small zone is operating that would have less flow than what is required by the boiler. The boiler more than likely would short cycle lowering the boiler efficiency and increasing the fuel consumption.
System flow is greater than boiler flow
The system flow is greater than the water flow required by the boiler. The only downside here is the temperature of the water going to the system. This may or may not be able to satisfy the thermostat.
Equal flow through the system and boiler
This is a good situation, the flow through the boiler is matching the flow required by the system. The boiler will continue to run until the heat demand is satisfied.
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accepts no responsibility for improper information, application, damage to property or bodily injury from applied information found on this website.