Need help- hydronic system with cast iron radiators

cd80

I am trying to install a hydronic system on a single story 1100 sqft ranch style house. I have a heatmaster MF5000 outside stove and old cast iron radiators of varying sizes that are likely overkill (but what I could find used). I need to install 6 radiators that I would like to have set up on 2 zones or have individual valves on each radiator (preferably). Currently have a single circulator pump mounted on the stove but willing to change that. Thanks

hot_rod

that seems like a large stove for1100 sq ft it may idle a lot. Any other buildings going to be added?

I think those are all unpressurized type stoves, some installers add a plate heat exchanger to make the home loop pressurized

hot_rod

is this a job you are going to pipe yourself? Here is an example that includes a backup boiler. One pump and two zone valves is a way to get 2 zones. The red line to the right of the pic is where two zone valves would pipe in.

Ironman

Don’t let any of the outdoor wood boiler people convince you that you can connect the house system directly to the ODWB. You need to separate the house from the ODWB using a heat exchanger as hot rod has shown.

You will have several long term issues if you try to short cut this, not the least of which will be oxygenated water which will rot the radiators.

Think about it: if houses could run unpressurized systems, then why has this industry been requiring it for well over 100 years?

GGross

That wood boiler can heat a small neighborhood of houses that size. If it were me i would look to selling that thing and using the money to pay for a small gas unit and several years worth of fuel personally. I could take care of my heating bills plus the cost of a DIY boiler for around 6-10 years for just the cost of that boiler and my house is about twice that size in a cold climate, zone 6, just a thought..

hot_rod

Here is what your piping might look like. Find the plate heat exchangers at most wood boiler suppliers.

If you do tie in a back up boiler,here is a piping that adds a shunt pump that sends a small amout of heat backto the OWF to prevent it from freezing if it is left un-fired.

leonz

https://forum.heatinghelp.com/discussion/204922/need-help-hydronic-system-with-cast-iron-radiators

The outdoor boiler you have is much too large for your home UNLESS you install more hot water storage and do batch burning every few days and use a heat exchanger in the home to push the homes cool water back to the heat exchanger keeping the homes circulation as a closed circuit with a second circulator.

EdTheHeaterMan

You really don't have a boiler that is too big for the home. You actually have a home that is too small for the boiler. You need to add several thousand sq ft of living space to your home in order to make that heater operate efficiently for your location. Maybe you can add 3 more stories above your first floor, and rent them out to your mother in law, and your brother in law. They are always the best tenants to have in my opinion. Your boss's daughter is another great tenant to have in there. Especially if she is college age and has lots of parties late at night. That will keep you young and on your toes.

cd80

I appreciate everyone's replies. That's a lot of help. I know the stove is oversized but I've had it for 15yrs at a previous home that was 1300sqft. Keeping fire on warm days can be an issue but I've learned to deal with it. Living in the mountains of WV it really works as it should in January and February when the temps are single digits and below a lot of days. I burn a lot of coal so that helps to keep a few hot coals on a warm day. On that house it was hooked to forced air but this house was only set up with electric baseboard heat so I thought radiators would be a better option than installing duct work. I do have a garage (720sqft) that I would like to hook to it in the future. I did not understand about the closed system using a plate heat exchanger. Thankful for that info. I think using the diagrams that you all provided I can get this thing going before the snow flies. Thanks everyone.

Ironman

Where are you in WV?

cd80

Crawley in Greenbrier County

cd80

Hot Rod, your diagram looks to be what I have in mind. Will I need a pressure tank and manifolds or can I just tee off of my main lines into to radiators and tee back into my return line to the plate heat exchanger?

hot_rod

Depending on the radiator size you could run 3 in series with 3/4" pex tube. or.

A home run piping uses1/2 pex loop to each radiator back to a manifold.

Home run gives you the ability to zone or adjust every radiator, 1/2" pex is easy to retrofit into homes.

This is an example with fin tube baseboard

Here is a homerun system @Ironman did with the tubing neatly organized in PVC pipe.

Ironman

A series loop will work if you have fin tube baseboards, but you’ll wanna use parallel piping with standing cast iron rads.

The homerun/manifold will work well with either.

I’m near Staunton, VA.