Indoor wood boiler plumbing questions

[peakbagger]

Mixing valve? This is a closed system. Two manifold - one at each end of the loops. Flow meters to show the GPM through each loop, these are adjustable.

If I were to send 120 degrees into the begining of the loops itd cool down way too much to heat anything. Unless multiple people are wrong, the settings for radiant heating in slabs are said to be 180 at boiler coming back about 160.

Boiler is rated for 3500-4500 if I remember correctly from the manual. Should be plenty.

You need to find some other people as the advice they are giving you is bad

 

[maple1]

Mixing valve? This is a closed system. Two manifold - one at each end of the loops. Flow meters to show the GPM through each loop, these are adjustable.

If I were to send 120 degrees into the begining of the loops itd cool down way too much to heat anything. Unless multiple people are wrong, the settings for radiant heating in slabs are said to be 180 at boiler coming back about 160.

Boiler is rated for 3500-4500 if I remember correctly from the manual. Should be plenty.

How big is the building you are trying to heat?

Boiler ratings for units of that type and age should not be relied on. That is an inefficient unit as far as boilers go.

And you are getting bad info from somewhere. More than once from info you have posted. And often here when you get good info, you dismiss it.

Good luck.

 

[Borjawil]

Multiple people you asked are wrong, you don’t send water to a slab that hot.

Doing more research seems 130-140 max. As low as 85. I will try this.

As for my vent question, appears I need to block the vents until I get a ceiling built and insulated. Thanks for the help.

 

[maple1]

Doing more research seems 130-140 max. As low as 85. I will try this.

Do you know how to accomplish that?

 

[Bad LP]

That’s an awfully high water temp for a slab. I’m running a max of 120 and I couldn’t stand anything higher. Add shoes or boots and it gets unbearable.
85 loop temperature is near useless from my own home experience. Those are the days I load up the insert but our home is also very open concept so the heat moves easily.

Do as you like with your money but please don’t complain when your project goes sideways. This place is chock full of real world burners with years of experience.

 

[Smoothride]

A barn with no ceiling will not heat no matter what you throw at it. Radiant floor heat in concrete has a max temp of140. Constant flow of 120 will give more heat than you know what to do with. But no insulation in a barn is just like heating the great outdoors. Radiant is a small window of btu but works well with great amounts of insulation. blowing hot air fills voids with poor insulation.

 

[Borjawil]

Sorry for the late reply. The walls and roof are insulated. But no ceiling. I understand that's a bit more area to hear up.

So I have turned down my settings on the boiler to stay around 120-140.

However I'm sure having boiler temps higher, with a mixing valve as previously mentioned would help. Lowest blower setting is 140 while circulating pump setting is 100.

Help on what I need for a mixing valve would be great.

 

[maple1]

I guess that answers my last question. You need to run the boiler at proper temps. If you have return water coming back into it less than 140 for very long you will be making creosote in it like nobody's business. Somebody already asked you about boiler protection from that, which you did not reply on.

Do a search for mixing. There is info all over the net about that, any discussion about in floor heating by anyone who knows anything about it would cover it.

 

[Tonty]

Barn is insulated. 10 ft to bottom of trusses, about 18ft to peak. No ceiling yet. Have an overhang on two walls with soffit vents. No insulation over the 1' gap between wall and ceiling. No insulation over ridge vent gap.

If I’m understanding correctly, these gaps most definitely need to be covered to get the heat built up in the barn. Otherwise there is a free air path into the building from the outside. If you want airflow between your roof and insulation, you’d have to design that in, but you don’t want outside airflow into insulated space

 

[Smoothride]

Bojawil, You need to run the boiler at 180, the radiant loops at a lower temp...ie 120. You need a mixing valve to accomplish this. Also, radiant fllor heat like constant flow. You are also going to want a thermostatic mixing valve piped into the boiler so it can stay hot. Like others on this post have said, you don't want your return water into the boiler below 140.