Am I making a mistake with this mixing valve

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infinitymike

infinitymike

Minister of Fire
Aug 23, 2011
1,835
Long Island, NY
My boiler guy is smart but not openminded.
He has done alot of primary/secondary systems, he has done large commercial heating and cooling systems, he is an engineer, he is a certified geothermal guy, and an AC guy as well. BUT NEVER has installed a wood boiler.

With that said every time I mention something I have read here he cringes and says "trust me I know what I'm doing"
And for the most part I do. But everybody here is talking about mixing valves for controlling the return temp. He says "just keep it simple stupid and lets not over think this" he just wants to put a ball valve to control the return mixing temp. He has actually said "if its a mechanical mixing valve what will operate it" and I said "I don't know you're the guy with the degree".

Am I letting him make a mistake. Should I force him to put in a Tekmar or Danfoss or something else?
If so what controls it?
 
Danfoss is like an auto thermostat. A spring and metal plate, calibrated for the temperature you want. It keeps the return temp to the boiler at or above the set point (typically 140F). You need one (or similar), AND a ball valve on the boiler supply to the valve to adjust the flow rate. Check the system diagram stickies.
 
Hunderliggur said:
Danfoss is like an auto thermostat. A spring and metal plate, calibrated for the temperature you want. It keeps the return temp to the boiler at or above the set point (typically 140F). You need one (or similar), AND a ball valve on the boiler supply to the valve to adjust the flow rate. Check the system diagram stickies.
Click to expand...

What model or part # ?

Thank You,
 
with comments like that i doubt if the state of NY considers him an engineer..
 
infinitymike said:
Am I letting him make a mistake?
Click to expand...

No, you are making a mistake. It's your system, you've paid your dues figuring out how it should work. If you fail to guarantee minimum return temperature on a solid fuel boiler it's your problem, stainless steel or no stainless steel.

You can go with a Danfoss or Termovar.

Or you can do a simple boiler recirculation loop with bang-bang pump injection controlled by a plain old Ranco aquastat, or a PID temperature controller.

Or you can use a motorized three-way valve same as Danfoss.

Or you can use a recirc loop with a variable speed ECM injection pump with a Tekmar control.

Your installer is a sharp guy, and as an engineer he will understand perfectly when you explain to him that the requirement is that the boiler return temperature stays above 140 degF, at a bare minimum, at all times, if at all possible, regardless of what the system return temperature may happen to be an any particular moment. That is the observable behavior for successful fulfillment of the requirement, however you choose to go about it.

Cheers --ewd
 
Nope. You need something like this http://smokelessheat.com/ProductPage.aspx?PID=36 You can search the net for suppliers. I drilled a 1/8" hole in the plate to prevent air locks when cold.(Inside the valve - not in the cover) I don't know what your booiler piping size is, mine is 1 1/4".
 
ewdudley said:
infinitymike said:
Am I letting him make a mistake?
Click to expand...

No, you are making a mistake. It's your system, you've paid your dues figuring out how it should work. If you fail to guarantee minimum return temperature on a solid fuel boiler it's your problem, stainless steel or no stainless steel.

You can go with a Danfoss or Termovar.

Or you can do a simple boiler recirculation loop with bang-bang pump injection controlled by a plain old Ranco aquastat, or a PID temperature controller.

Or you can use a motorized three-way valve same as Danfoss.

Or you can use a recirc loop with a variable speed ECM injection pump with a Tekmar control.

Your installer is a sharp guy, and as an engineer he will understand perfectly when you explain to him that the requirement is that the boiler return temperature stays above 140 degF, at a bare minimum, at all times, if at all possible, regardless of what the system return temperature may happen to be an any particular moment. That is the observable behavior for successful fulfillment of the requirement, however you choose to go about it.



Cheers --ewd
Click to expand...


Thanks.
You are right.
In the end IT IS MY system and I am paying him to install it.
 
Hunderliggur said:
Nope. You need something like this http://smokelessheat.com/ProductPage.aspx?PID=36 You can search the net for suppliers. I drilled a 1/8" hole in the plate to prevent air locks when cold.(Inside the valve - not in the cover) I don't know what your booiler piping size is, mine is 1 1/4".
Click to expand...

I have 1" pipe.

Thanks that seems real simple. How do you set the temp control or do you buy it allready set to a temp?
 
barkeatr said:
with comments like that i doubt if the state of NY considers him an engineer..
Click to expand...

yeah it makes me wonder too!!
 
Hunderliggur said:
Nope. You need something like this http://smokelessheat.com/ProductPage.aspx?PID=36 You can search the net for suppliers. I drilled a 1/8" hole in the plate to prevent air locks when cold.(Inside the valve - not in the cover) I don't know what your booiler piping size is, mine is 1 1/4".
Click to expand...

I'm a little confused which one is it? does it go on the supply or return side?

look at this sheet http://smokelessheat.com/Media/FurnaceDocuments/Danfoss/Information.pdf
 
I have the one pictured it goes on the return side and keeps return to boiler at 140 minimum. There is a new and improved model. Valves on all three sides are a good idea if you ever need to service.

I have temp gauges before and after and it works as stated. With nothing in its place my boiler would be getting 60 degree water for several hours on initial start up.

I will pm you my phone number, call me and I can give you the number of a Danfoss tech he was very helpful. I asked him about drilling a hole in the plate, he said no.

Gg
 
infinitymike said:
Hunderliggur said:
Nope. You need something like this http://smokelessheat.com/ProductPage.aspx?PID=36 You can search the net for suppliers. I drilled a 1/8" hole in the plate to prevent air locks when cold.(Inside the valve - not in the cover) I don't know what your booiler piping size is, mine is 1 1/4".
Click to expand...

I have 1" pipe.

Thanks that seems real simple. How do you set the temp control or do you buy it allready set to a temp?
Click to expand...

Tell your guy it's just like an automotive thermostat, which it is, pretty much exactly, with a pre-set temperature, same as with an automotive thermostat.

Same as with a car thermostat the Danfoss will keep you boiler at the minimum operating temperature it needs to be at, same as a car engine needs to be kept above a minimum operating temperature.

Print out the data sheet and application notes. As soon as your engineer sees what it is you're talking about I bet he'll sign right up for what needs to be done.

--ewd
 
Thanks guys,

It is very basic and will definitely put it in!

I just have to find a local supplier that I can get it from.
 
Mike,

You and I have the same boiler. The pipe supply from and return to size is not 1". It is 1.5 inches. My danfoss is 1.5". Make sure you get the right size! It is going on the return side and your returns at the bottom of your boiler are 1.5", same as supply coming out.
 
Gasifier said:
Mike,

You and I have the same boiler. The pipe supply from and return to size is not 1". It is 1.5 inches. My danfoss is 1.5". Make sure you get the right size! It is going on the return side and your returns at the bottom of your boiler are 1.5", same as supply coming out.
Click to expand...

Yes, I believe they say 1" is good for up to 80,000 btus... 1 1/4" something like 140,000 btus...1 1/2" would be even better. With 1" the velocity of the water will be too fast as well. I think most of us on Hearth have used 1 1/4".
 
Mine is 1-1/2 from boiler to tank, and all through primary loop, and back to boiler and tank. Then the zones feed off of this primary loop.
 
huskers said:
Gasifier said:
Mike,

You and I have the same boiler. The pipe supply from and return to size is not 1". It is 1.5 inches. My danfoss is 1.5". Make sure you get the right size! It is going on the return side and your returns at the bottom of your boiler are 1.5", same as supply coming out.
Click to expand...

Yes, I believe they say 1" is good for up to 80,000 btus... 1 1/4" something like 140,000 btus...1 1/2" would be even better. With 1" the velocity of the water will be too fast as well. I think most of us on Hearth have used 1 1/4".
Click to expand...

Well, I was going to use 1.25" pex but couldn't find any locally only on pexsupply.com So my guy said 1" would be fine.

I ran 1" pex supply and return lines from the OB to the WG they are about 70 feet apart and I only needed 4 elbows.

We haven't made any connections to either unit. I assume I can Increase back to 1.5?
 
First - thank you for sharing your install. I am enjoying following the progress.

I'm a victim of poor planning and investigation. I shoulder the responsibility, but I figure I would share my story with you.

I regret not using or knowing about 1 1/4".

Granted my OWB was 175' from the house, I had to move it to 100feet from the house and now get minimal heat loss. So in that aspect you should be fine, however I'd hate to have a boiler with ratings like yours has just to thermal transfer constrictions on pipe that size. It would be like a governor on a drag car.

It sounds like what is done is done at this point, but I hope these lines are accessible in case you would like to replace them.

I say follow your hard earned knowledge and tell the guy he builds to your plan unless otherwise specified.
 
I am not a boiler guy or an Engineer, but from what I have seen I think your primary loop from Wood Gun to oil boiler and zones and returning to Wood Gun should be 1-1/4" at least. 1-1/2" Would be better. Then your reduction should be down to the zones piping. But like I said, that is just me. Your boiler is going to put out more like 120,000-130,000 BTUs. The larger seems like it would be better.
 
Hunderliggur said:
Nope. You need something like this http://smokelessheat.com/ProductPage.aspx?PID=36 You can search the net for suppliers. I drilled a 1/8" hole in the plate to prevent air locks when cold.(Inside the valve - not in the cover) I don't know what your booiler piping size is, mine is 1 1/4".
Click to expand...
I can only find a Danfoss at my local supplier it is code# 065B8938 for 1" pipe good from 85*-140* or a Taco 5004

Will either one work? Than dafoss is $108 and the taco is $140
 
Countryboy1966 said:
First - thank you for sharing your install. I am enjoying following the progress.

I'm a victim of poor planning and investigation. I shoulder the responsibility, but I figure I would share my story with you.

I regret not using or knowing about 1 1/4".

Granted my OWB was 175' from the house, I had to move it to 100feet from the house and now get minimal heat loss. So in that aspect you should be fine, however I'd hate to have a boiler with ratings like yours has just to thermal transfer constrictions on pipe that size. It would be like a governor on a drag car.

It sounds like what is done is done at this point, but I hope these lines are accessible in case you would like to replace them.

I say follow your hard earned knowledge and tell the guy he builds to your plan unless otherwise specified.
Click to expand...

My boiler is in an attached garage/shop.

The piping is completly exposed as it runs along the ceiling of my basement and then pops out thru the foundation wall in the garage.

Hopefully it will handle the load. I guess I could always change it in the summer.
 
Stop for a few minutes Mike. Wait until someone responds who is a little more knowledgeable than I am. I don't want to see you make a mistake that will cost you efficiency all this winter and possibly cost you more money, a lot more, if you have to change everything next year and pay someone to do it. Could lead to thousands of dollars more for you. I don't know what your paying your boiler guy, but they usually are not cheap. Right now, a few hours, or having him stop, get what you need, and have him come back may be better. I know, but I am just sayin. It is pretty warm out right now. Looks like it is going to stay that way for a while.
 
so a mixing vavle is required on the return side of a gasser but would that be the same "rule" for a conventional wood boiler? how would this be plumbed in if my wood boiler is going to be hooked into my oil boiler. not sure if series or parallel is my best bet yet and what affects it would have on my return temp to the wood boiler.
 
91LMS said:
so a mixing vavle is required on the return side of a gasser but would that be the same "rule" for a conventional wood boiler? how would this be plumbed in if my wood boiler is going to be hooked into my oil boiler. not sure if series or parallel is my best bet yet and what affects it would have on my return temp to the wood boiler.
Click to expand...

91

I would like to suggest you start a thread with your questions regarding your system. Which may be different than Mike's. Mike is doing his install right now. And he needs advice from some of the experienced guys on here. Hopefully it will work better that way for both of you. Just a suggestion.
 
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