Presently we have a steel boiler serving single pipe steam to 21 units that has a hot water coil in need of replacement. The boiler is currently running Natural Gas but is duel fuel (also #2 oil). The burner is a pretty big ~1,500,000 BTU POWERFLAME / C2-G0-15.
As we look to replacing the coil, I was thinking about more efficient means of hot water generation (so as to not have to fire up that big power flame every time in the summer). Since we have natural gas already, should look to 1) one or more glass hot water heaters 2) storage tanks off the coil 3) indirect water tanks 3) something else 4) or just replace the coil inside the boiler (as efficiency gained might not be helpful)?
Also, and to add context, we do have a problem with hot water ever reaching temperature in the back of the building (there seems to be enough water, but it's always luke warm), so was thinking a circulator pump might help here (as it did wonders at another building with similar issues)? Lastly, may wind up adding more dishwashers and laundry down the road so definitely wanted to oversize needs a bit.
- most efficient needs of hot water generation in this case?
- will a circulator pump help the issue at the back of the building?
- how should I start to look at capacity given current and future needs?