Primary secondary piping for boilers

Bob Rohr Posted By Bob Rohr, Jan 15, 2008 at 12:27 AM

  1. thehaas

    Member 2.

    Nov 22, 2009
    north east pa
    i have a d.s.machine coal wood boiler.i had oil boiler that i tied in totalked to lot of people asked plumber got million answers and many plumbers not interested in installto much work for them and area they never do.basically they want boiler with all controlls on it ready to wire to 120 then hook up oil lines takes them about 8 hours and they make 1500 to i hooked up my self running about 2 years plumbed it series circuit not put 3 inch and quarter valves in oil fired boiler return line shut middle one off open two outers so flow is .out of top wood boiler down to oil boiler up threw oil boiler out to base board back down to return into bottom of wood boiler.when i dont use wood boiler i close outer valves on return line open middle valve shutting off water flow to wood boiler.i think i got valve idea from alternate heating web dump zone is separate zone ran threw old cast iron radiators boiler holds 85 gal radiators are half capacity around 40 gal.dump zone has its own circulator thats turned on by aquistat switch on top off wood boiler also has its own zone valve also has another one thats normally closed until power failure the it gravity flows.all controlls are taco boxes have step down transformer built in hot water tank connections called prority zone that means when hot water calls for heat heat zone are turned off till hot water up to temp no shortage of hot buddys electrician and helped wire.taco controll boxes really make install easier.4 wire zone valves 2 wires for opening motor off valve ,other to wires are end switch that turns circulater on ,all locations for wires are labeled inside box real easy.other controll box is for dump zone aquastat switch on top of wood boiler turns on controll box that opens dump zone valve and turns on circulater.originally i hooked up wood boiler parralel to oil boiler return to return out put on top hooked to oil out put did not work correct wood boiler temp around 190 oil boiler around 140 more water was circulating threw oil than wood boiler.all electrical on original oil boiler is factory no changes.have stainless steel type a chimney heats up quicker better draft easier cleaning.had in block chimney low draft creosole build up plus that red clay liners are junk and coal fumes detroy in no time,had many discussions with people about chimneys they are good for oil or nat gas ormaybe old fire place,not for coal chimney run around 2000 block chimney aruond 2500 with in stall ,plus ss goes up lot faster.basically no contracter wants to work unless he can make 1500 a day on project or min 500 a day,they all cry about being broke but dont want to work unless they can hit it big on you.i work on cars hourly rate is 40 dollars hour when contracters come to us they sure dont want to pay talk about cheap when hooking these thing up your on your own unlee you want to pay like 10000 intall.any question e mail me i dont mind giving advice mine is up and running great ,best way to learn is make mistakes and learn from them ,you could draw all diagrams plan out then start and everything changes
  2. surviverguy

    New Member 2.

    Mar 19, 2012
    Three speed circulators have lower wire to water efficiency than single speed circulators. You come out ahead calculating the headloss and needed flow rate and buying the right circulator for the job. The variable speed circulators are very efficient as well. The three speed units are mostly energy hogs.
  3. ALASKAPF185

    Member 2.

    Feb 3, 2012
    That seems to be a pretty general and broad statement for all circs. I haven't read anything about this before. A Grundfos 15-42 3 speed is well under 100 watts at medium its only 54 watts for an example.
    Some standard piping designs, these are from the caleffi idronic's edition on wood boilers. We have always drawn the load from the buffer tank and the boiler only heats up the battery, unless there are multiple types of boilers or an IDWH. This way the buffer tank or storage acts like a hydraulic separator/air removal/dirt separator all in 1. Thus no need for a "primary loop" and primary pump. When sizing a primary loop circ, when a design calls for one, the pump is sized for 2 feet per second as the idea is to keep the primary loop very low head loss so the secondary circuits are hydraulically invisible to each other.
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    Trex83 likes this.
  4. Trex83

    Member 2.

    Jun 4, 2012
    Far Eastern Ontario, Canada
    Thanks Alaska. Now my mind is at peace from all these P/S discussion. Doing it the European way with water storage seems simpler in me and my dads mind. Setting up like Figure 7.1 this summer. We used a piping design from Switzerland. The only difference is that the loop to the house is drawn off the first tank and the garage is drawn of the second tank. The radiant floor to the garage doesn't need to be as hot as what is going to the house.
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