Heating a 13 story, 84 yr old building

[PropertyManager]

Hello, my boss is thinking of changing the heating system in our building, and I would like to hear from you what your best, most economical ideas are. Currently we have a one pipe boiler system that heats the building through radiators. I figured we could turn it into a 2 pipe system, don't know how much work that would be though. So tell me what you think guys!

[ascj]

If the one pipe system has been treating you right. Then just replace the boiler. Converting to a 2 pipe will be very costly. The only advantage to a 2 pipe is you can use thermostatic rad valves.

[PropertyManager]

Thanks for the input. OK, so the 2 pipe system is out, and the replacement of the boiler is out, what is left. Is there anything out there that is economical on gas/electricity? Something that will not cost us a million dollars to install?

[ascj]

What are you trying to achieve? Are you trying to lower utilities?

If lower utilities is the case, then you have 2 options. 1) Replace the boiler with a more effiencent one. 2) Tighten up the building

What pressure you running the boiler at?

[PropertyManager]

We run it at 5. We alternate it manually on and off and have to guess what to set it for at night. I think that a night stat set at 63 degrees would help allot, our gas consumption was up by $55,000 last year from the previous year.