Optimal Boiler Configuration Question

Alan_3

I have a gas fired hot water boiler which can be configured several different ways. I am trying to determine which of the two methods below would be the most fuel-efficient.

Method A: Maintain a constant boiler temperature and turn on the zone pumps when a call for heat is made.

Method B: Turn on the Zone pumps and fire the boiler when the call for heat is made.

I have programmable thermostats that fire up for about an hour in the morning and then again for about 4 hours in the evening (they may also fire during the day if the temperature drops really low). Using Method A the boiler will come on and off every time the temperature of the boiler drops, but will only need to heat the boiler up a few degrees at each firing. Using Method B the furnace temperature may drop considerably and therefore a lot more energy is needed to bring it up to temp, but this will be done only twice (once in the morning and once in the evening). I am not concerned with the time it will take to come up to temp. I have thermostats with fuzzy logic and it calculates backward as to when to fire the boiler so the temperature is correct at the desired time.

I know that I may have oversimplified the question and there are several other factors that might play a role, but I wanted to prevent over complicating the matter.

If you have any insight or can point me to information on this topic, I would greatly appreciate it.

Alan_3

Optimal Boiler Configuration Question

I have a gas fired hot water boiler which can be configured several different ways. I am trying to determine which of the two methods below would be the most fuel-efficient.

Method A: Maintain a constant boiler temperature and turn on the zone pumps when a call for heat is made.

Method B: Turn on the Zone pumps and fire the boiler when the call for heat is made.

I have programmable thermostats that fire up for about an hour in the morning and then again for about 4 hours in the evening (they may also fire during the day if the temperature drops really low). Using Method A the boiler will come on and off every time the temperature of the boiler drops, but will only need to heat the boiler up a few degrees at each firing. Using Method B the furnace temperature may drop considerably and therefore a lot more energy is needed to bring it up to temp, but this will be done only twice (once in the morning and once in the evening). I am not concerned with the time it will take to come up to temp. I have thermostats with fuzzy logic and it calculates backward as to when to fire the boiler so the temperature is correct at the desired time.

I know that I may have oversimplified the question and there are several other factors that might play a role, but I wanted to prevent over complicating the matter.

If you have any insight or can point me to information on this topic, I would greatly appreciate it.

Paul_11

I choose method B

Given those two options I would go with B. I can never see the sense in firing a boiler when no heat is required.

Paul

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Mark Wolff

cycling

Method B will be more efficient. Short cycling on the boiler to maintain temp. will cost extra fuel. It takes less energy to heat up twice, rather than keep up to temp.