Thanks for the excellent forum and advice! I would like to ask if our situation would warrant going from steam to FHW?
For a bit of background on us, we have an oil + 1 pipe steam system now, and the boiler is 30+ years old. We just moved into this 1920's house, and it is around 1900 square feet + 500 sq feet of finished attic space, and is heated by 11 radiators currently (5 for the 2nd floor rooms upstairs plus 6 downstairs). We have no idea how well things work, as we moved in during the summer. But, we know oil bills ran quite high on this old system. We would like to replace the current system before the winter comes around (ie NOW) with a natural gas system and are looking at FHW vs staying with steam.
We are considering converting the steam system to forced hot water (first floor) + hydro air (second, third floors). We're happy to hear any advice. Here's why would we move away from steam:
1. Piping & boiler location are changing in the basement
a. Some of our current dry return basement piping hangs
down as low as 10" below the ceiling -- given all the complexities of pitch and steam/condensate return flow we're going to have to re-pipe most of the basement-area-underside first floor radiators because of the desire to refinish the basement. We also have a significant portion of wet return pipe that was once buried in the concrete and was moved to be flush on top of the concrete (old pipe probably failed), which also runs across a doorway and around the basement (you have to step over it).
b. We would like to refinish the basement,creating a slightly raised floor and drop-ceiling. The wet-return on the floor and the dry-return pipes 10" below ceiling make the refinishing of the basement hard. Long-story short, we're re-piping the 6 first floor radiators. If we're already going to re-pipe why wouldn't we go forced hot water?
c. Our radiators are connected across top, but would need a bleeder valve installed and the steam valves removed. I know it's risky they might leak, the worst case scenario we'd replace all six. (obviously the caveat here is that we do the EDR calc and make sure the HW at a lower temp can heat the house, and we will!)
2. The second reason we'd consider moving away from steam is because we want to install central AC, at least upstairs, which means we're running new ductwork in the unfinished part of the attic (3rd floor) and putting a vent in each bedroom ceiling plus our 1 bathroom. That ductwork exists, and the radiators currently cause havoc on 4 small rooms with furniture placement.
3. Zoning, we would like the first and second floors to be on different zones. If the second floor has ducts, why not just make it hydroair with a FHW pex run to the attic. This would also remove 6 radiators from the second floor. Since heat rises from the first floor, perhaps not so bad...radiators FHW first floor, hydro air second floor.
4. Hot water, we always seem to run out of hot water and I can't say I trust the instant ones -- so a superstor type tank is preferred for many reasons (reliability, efficiency, and the fact that they have a have a lot of gallons per refresh). I can't run a superstor off a steam heating system, can I ?
5. Efficiency -- yes, efficiency is important to us.
6. Lastly -- we'd like to put in addition on in 2-4 years, but are not ready yet. This would mean adding 500 to 1000 square feet to the house (from the 1900 main to 2900 say). It'd be ideal to put in a system that could handle this. Isn't this another reason to go FHW/zones/modcon?
My overall questions then:
The idea of FHW first floor, converting the steam radiators, plus hydro air second floor, plus superstor -- bad idea, good idea?? Or am I off base?