Mod con on second floor, manifolds in basement home ran to second floor rads. Thoughts?

Bill751

I have an old two story duplex with two oil boilers currently in the basement, one for each floor/ tenant. Both systems are hot water cast iron rads. The house including the heating systems have been reworked and added on to a number of times since 1860. The house is also in a flood zone and so due to that a few other reasons, I'd like to put a gas mod con on the second floor to heat the second floor. For now the mod con for the first floor is going in the basement. I'd prefer to move that to the first floor but it's just not going to happen this time around.

I have the perfect area on the second floor to install a mod con. There's already a cold water supply and a drain coming up in that room and it wouldn't be a problem to run the natural gas line up, it's fairly central in the house. Also a good location for venting. I had several heating contractors come by last fall and they agreed it's an ideal location for a mod con. unfortunately the only other thing they seemed to agree on is that I "don't need a heat loss calc" typical stick with what you have kind of guys, despite the boilers being twice the size needed. I know better than that and so that aspect is under control. Due to " not needing a heat loss" and a few other things they said, I don't feel comfortable taking any advice from them without doing my own research. I've just moved on from them and have been looking around for someone else. In the meantime I've been researching and trying to get an idea of what I'd like to do and how I'm going to do it.

I've worked in various construction trades, maintained rentals, remodeled homes and now work in the natural gas industry. I started out pipelining and now work on the compressor crew building natural gas compressor stations. I say all that to give some background prior to saying that I plan to do some of the work myself as far as the carpentry and radiator supply/ returns go. This old house needs new domestic piping as well. so while I'm re piping the rads, I'll put in new lines for the domestic.

I've been doing some research on this site and others which has led me to the conclusion that I would most likely go with a HTP UFT. I want the 10 to 1 turn down and also hope to be able to direct pipe it rather than the delta T suffering due to primary/secondary. I had hoped to direct pipe into manifolds and then homerun the rads with oxy barrier pex. To do this however would require me to pull up the 2nd floor throughout the house to each rad. The dining room and main bathroom even have massive amounts of floor leveler on the sub floor and the bathroom is ceramic tile. The rest is just laminate and carpet. all in all that would be quite a bit of work though. The only way it would be affordable is for me to do the work and that's OK, just wouldn't be looking forward to it with all the other projects I have going on.

I started thinking what other alternatives might there be for my situation with being in the flood zone . Putting the 2nd floor boiler on the first floor is not really an option. I only have an area for one boiler on the first floor and that will some day be taken up by the first floor boiler. So the only alternative I know that wouldn't require tearing up the floor to every room in an 1800 sq ft apartment would be as follows. Install the mod con on the second floor and run either 1" or 1 1/4" copper supply and return down to the basement. I would then put the manifolds in the basement and homerun up to each rad on the second floor. Then back down to the return manifold in the basement. would that work OK and what challenges might it create? Originally I completely dismissed doing something like that as I preferred to keep the runs as short as possible and also try to limit the heat lost in basement piping and on each individual supply/return run to 9 rads running up through the first floor. If it wasn't a two unit building with separate utilities, losses on the first floor wouldn't be losses at all. In this case I'd consider them losses, maybe they're not enough to worry about, I'm not sure. I do have easy access to all the vertical runs that would travel up through the first floor. so as far as extra work goes, this option would by far be the easiest. It would however add roughly 180 feet of extra Pex and roughly 30/35 feet of extra 1" or 1 1/4"... Would this be a viable option or does it sound ridiculous VS just taring up the floor? Would it likely work with the UFT as a direct pipe setup or would I need to possibly consider primary/ secondary? If it would work with direct piping, would I still be able to use one pump and locate that near the boiler? Am I wrong in thinking that because the system is pressurized that it shouldn't really matter that I'd be pumping down,up,down up to get back to the boiler? I'll just have a little more head due to pipe length correct?


Additional side notes:

1. tearing down the ceiling in the fist floor rather than tearing up the floor in the second floor apartment is not a third option. mainly because due to the construction and many changes, layers and additions since 1860, that would be far less desirable than just pulling the floor from above. secondly I'm currently living in the upstairs apartment so working from above would only disrupt my life, verses working in the first floor apartment would disrupt the tenant who has two very inquisitive little boys.

2. Tearing up the floor not only adds all the extra labor ( for me) it would also require some new floor coverings and other material. Not that this is a major deciding factor, just pointing out the cost for extra pipe to put the manifolds in the basement would be less than the cost of floor coverings going the other route. so the pipe expense wouldn't be an issue and be the cheaper route.

3. I understand the idea behind not picking the boiler before the contractor and I can totally agree with that. However I do have a local HTP supplier so that's a plus. And if I went with a unit the local contractors were comfortable with and recommended, so far that leaves me with either a gun conversion on the current Weil Golds or GV90+'s both in the basement in a flood zone. So I'll roll the dice and plan for a UFT unless a better option comes along in the meantime.

Zman

What you are trying to do does not sound unreasonable. Putting a boiler on an upper floor is fairly common. Be sure to install a low water cutoff for that application.

The water does not care if it is going up, down or around in a closed system. As the distances get longer, the pipe and circ sizing gets more critical.

It sounds like generating an accurate scope for contractors to bid is going be a challenge on this one. It might pay to hire a pro to do a design that you could then put out to bid. This would give you the piece of mind that the system will function correctly as well as "apples to apples" bids to compare. Is there anyone in the "find a contractor" list in your area?

Bill751

Zman,

Thanks for the reply and suggestions. Agree a LWCO would be absolutely required here. Good to know the up and down several times would be OK. At first I thought it was kind of crazy, then thinking about how the system is pressurized I began to wonder if it was acceptable. Being that it is, I just may go that route.

I did look at the contractor list not so long ago . I believe the closest contractor was a little over 2.5 hours away. Worst case I'll just keep learning and get a rough design and keep tweaking it and asking questions until I get something satisfactory.

Within a day or so I'm probably going to post some pics of my first draft layout of the near boiler piping for the first floor. I had a newer contractor who was going to do the install some time ago but I think the mod con scared him away. He bailed shortly before he was supposed to put it in. I have just about everything to do the job. So I figured why not lay it out and see what I come up with.