Add hot water loop or pump additional zone?

Thecrow

I have a new National (Sister of Crown Boiler in my area) gas fired steam boiler for my home and it works flawlessly. I just finished my attic which consists of two bedroom fairly small and a larger den area. My plumber told me as well as the plumbing supplier who used a heating calculator etc upon the installation that the boiler would be perfect size to add a hot water loop or zone (baseboard hot water heaters supplied by 3/4 copper pipes and a circulatory pump) to heat my upstairs. I need advice on how this will work. I can pipe the copper, solder etc myself. I cannot however, imagine myself installing the pump if required and anything else. Does anyone have any solid advice on a ballpark or the design and about how much it should cost here in Northeast Pennsylvania? I have a little one on the way and he will be needing that upstairs bedroom done right away. thanks in advance.

Jamie Hall

I presume that for some reason you are not thinking of adding steam heat upstairs? If you have room for the plumbing required for hot water heat, surely there is space to run the pipe or pipes needed for steam?

Or is it that your plumbers don't know how to do it... ?

Anyway, adding a hot water loop is perfectly possible -- but it's a little more complicated when you are going above the boiler water level, since the hot water loop will have to be under pressure and sealed -- and the boiler isn't.

So... is there provision for a domestic hot water coil on your boiler which isn't being used for domestic hot water? That may have enough capacity to handle the proposed loop. Otherwise you need a heat exchanger -- I would suggest an indirect hot water tank powered off the boiler which will also serve as a buffer tank -- and two pumps, an expansion tank, and air separator, etc. and controls in addition to the radiators and plumbing. If there is provision for a DHW coil, and it has the capacity, and it isn't in use, then you'd only need one pump and an expansion tank and air separator etc. and controls...

On the whole, I'd add steam... a lot simpler.

Thecrow

Thank you Ill get some pictures of the unit today and post them. I have with the help of this forum added various radiators myself. I would be comfortable to do it again. I know I have another tap that I can run a second main pipe off the boiler to the upstairs. Its steam so only one pipe. Once i get it upstairs, I can branch off of it and add two radiators one smaller and one larger one.

Thecrow

However, how will the controls work separate for the 2 zones with two thermostats? I currently have the nest wireless and it works beautifully

Thecrow

Here is the boiler

Hap_Hazzard

Are you thinking of adding another riser to the boiler to supply the attic radiators?

Thecrow

If that's necessary I will hire a plumber, that's beyond my capabilities. Trying to do it myself, however, if it's too difficult I'll have it done by a good licensed steam plumber. Not sure what to do here any help is greatly appreciated

Jamie Hall

Ah. Well, if you want the upstairs zone to be on a separate thermostat, that gets messier. If you just want it cooler most of the time that's easy -- slower vents. But... if you want true two zone control, then... steam really isn't happy doing that. You could put thermostatic vents on the upstairs radiators, but that's not always satisfactory, as that will simply mean that they won't heat some of the time when the downstairs is on. But they won't ask the boiler to come one for upstairs when the downstairs is off.

Hap_Hazzard

I'll let the pros weigh in on this, but I've been told that running supply piping directly from the boiler is a no-no. You should connect the risers to a common header, then take your supply mains off of the header. How many risers you use should depend on the steam velocity coming out of the boiler, and adding more load will increase the velocity, so you might want to use both risers, but I don't know what your current load is or whether the velocity is getting close to where it's necessary, but adding another riser and a header is going to be a major job. It might make sense to hire a pro, but a lot of use DIYers have handled comparable jobs with the guidance of the pros in this forum.

The way your boiler is piped right now is not very good. I don't like the way the equalizer is piped into the riser. It's not helping to return condensate to the boiler. If they'd used a tee instead of that second elbow, they could have run the equalizer from the bottom of it, so all the condensate coming down from the main would return to the boiler via the equalizer instead of the riser. When condensate returns via the riser, it meets the onrushing steam, cooling it down and making the boiler work harder, and also making the steam wetter. You can help matters by insulating the riser and the main to reduce the condensation that's happening there. If it makes your garage too cold you can always put a small radiator on your wet return. Also, perf strap is not an approved hanger for a 2" steel pipe, so you might want to get a real pipe hanger while you're at it.

Hap_Hazzard

Btw, I agree with Jamie about using vents and balancing to control how much heat you get on each floor, but that only works when your distribution piping is done correctly.

You can run a hot water zone from the wet return, but that's a lot easier to accomplish when you're using it to heat a basement or garage than when you're heating an attic. Pushing the water back upstars requires a pump, and if your piping isn't well insulated, you'll just end up heating the areas it passes through on its way to the attic.

Thecrow

I don't particularly like the way its piped either. It works great I guess I could insulate it like mentioned. I never heard of runni g a radiator off a wet return but I'm no plumber. Where would that exactly go? Still, what qou be the best way to get heat to my attic? I have 5 radiators running now so whatever is needed I'm certain this boiler can handle. I know a plumber would charge me a fortune to add a riser, and I certainly don't have that kind of cash laying around with the little one on the way

SeanBeans

Crazy thing is it actually heats your house.. there is no header or equalizer.

Hap_Hazzard

There is an equalizer. It's just not doing much other than equalizing.

Thecrow

Like I said, it works very well. In fact, the previous boiler a crown, was piped the exact same way and that was almost 30 years old. The question remains however, what's the best route to heat the attic?

Hap_Hazzard

Steam, if you can pipe it in. Otherwise I'd go with an electric baseboard.

Thecrow

Do I need to add a riser, header to use steam? Electric in this area would be prohibitive as its a private company through the city.

ethicalpaul

> but it's a little more complicated when you are going above the boiler water level, since the hot water loop will have to be under pressure and sealed -- and the boiler isn't.

I have to disagree with you here, @Jamie Hall . You don’t have to seal the loop to have it hold water.

See https://heatinghelp.com/systems-help-center/how-to-run-a-hot-water-zone-off-a-steam-boiler/

But I agree steam would be better. No pumps or loops etc

Jamie Hall

ethicalpaul said:

> but it's a little more complicated when you are going above the boiler water level, since the hot water loop will have to be under pressure and sealed -- and the boiler isn't.



I have to disagree with you here, @Jamie Hall . You don’t have to seal the loop to have it hold water.



See https://heatinghelp.com/systems-help-center/how-to-run-a-hot-water-zone-off-a-steam-boiler/



But I agree steam would be better. No pumps or loops etc

Now that I think about it, you're right, @ethicalpaul . It will hold water. Pretty good vacuum at the top when the pump is off, but it should hold. Your pump would have to generate enough head, though, to get the water up there initially (once you got the loop going, it would be just like any other circulator, of course).

ethicalpaul

Or you can use a purge port to fill it with a hose, if available, then close the port and let the pump take over after that (I’ll be doing this in the spring so I’ve been thinking about it so much!)