Bob NH
In the Trades
RE Carpenter Paul
I direct a Bible camp and have two buildings that house 32 people each. the original hot water storage tanks that were installed are not sufficient. The heating systems are both boiler, in floor heat. the tanks are boilermates. I was looking at installing instant hot water after the tanks. But now I'm not sure that, that would be sufficient either. There are four showers in each building and eight sinks.
The Amtrol BoilerMate has a heat exchanger inside the tank. Your capacity will be limited by the boiler capacity and the heat exchanger capacity in the boiler and the boilermate. http://www.amtrol.com/pdf/bmclassicbroch.pdf
You can probably improve capacity if you put in a control system that will not let the boiler circulate to the floor heating when the temperature drops below a certain level. You will also get some improvement in heat transfer if you increase the flow rate of the pump that is circulating between the boiler and the boilermates.
Analyze the Problem:
1. How many BTUs do you need in that peak hour to meet the hot water demand. Assume that the heat circulator will be off if water heater demand is high.
8.34# per gallon x Gallons per hour x(120-cold water temp)= BTUs per hour required
2. Determine if your boiler output (not input) is enough to meet your demand. Check manufacturers specs.
Solution:
If your boiler has enough capacity, then put in controls to give hot water priority over heating and check with boilermate supplier to make sure you have enough heat transfer capacity to get all of the heat out of the boiler.
You might talk to the heating system supplier about putting the boilermates in series and running the heating loop from the boiler in series through the boilermates in the opposite direction. That would minimize the mixing of incoming cold water to the outlet and would tend to get a little more hot water before it runs out. It might require a circulator pump with more head (pressure capability).
There are certainly variations on the solution but they all start with knowing how much heating demand you have. An inexpensive water meter on the cold water inlet to your heaters (About $125 for a 1" rebuilt meter with connectors from USA Bluebook) will tell you how much water is being used.
I direct a Bible camp and have two buildings that house 32 people each. the original hot water storage tanks that were installed are not sufficient. The heating systems are both boiler, in floor heat. the tanks are boilermates. I was looking at installing instant hot water after the tanks. But now I'm not sure that, that would be sufficient either. There are four showers in each building and eight sinks.
The Amtrol BoilerMate has a heat exchanger inside the tank. Your capacity will be limited by the boiler capacity and the heat exchanger capacity in the boiler and the boilermate. http://www.amtrol.com/pdf/bmclassicbroch.pdf
You can probably improve capacity if you put in a control system that will not let the boiler circulate to the floor heating when the temperature drops below a certain level. You will also get some improvement in heat transfer if you increase the flow rate of the pump that is circulating between the boiler and the boilermates.
Analyze the Problem:
1. How many BTUs do you need in that peak hour to meet the hot water demand. Assume that the heat circulator will be off if water heater demand is high.
8.34# per gallon x Gallons per hour x(120-cold water temp)= BTUs per hour required
2. Determine if your boiler output (not input) is enough to meet your demand. Check manufacturers specs.
Solution:
If your boiler has enough capacity, then put in controls to give hot water priority over heating and check with boilermate supplier to make sure you have enough heat transfer capacity to get all of the heat out of the boiler.
You might talk to the heating system supplier about putting the boilermates in series and running the heating loop from the boiler in series through the boilermates in the opposite direction. That would minimize the mixing of incoming cold water to the outlet and would tend to get a little more hot water before it runs out. It might require a circulator pump with more head (pressure capability).
There are certainly variations on the solution but they all start with knowing how much heating demand you have. An inexpensive water meter on the cold water inlet to your heaters (About $125 for a 1" rebuilt meter with connectors from USA Bluebook) will tell you how much water is being used.