Pipeing question

[kopeck]

So I have a question about my pipeing.

The way I have everything setup now I have two 007-f5s in line, one that acts as the system circulator and one that used to be the system circulator before my wood boiler was installed and sits on the cold water return on my oil boiler.

I have a 3-way motorized ball valve that switches between wood & oil.

I'm pretty sure the circulator on the oil boiler is now redundant when I am running on oil. In fact if I understand correctly it's boosting the system circulator and probably over pumping everything.

The other thing is that blue item in the diagram is a thermostatic valve, seems like the circulator on the oil boiler would be working against it...

I do seem to be getting some cavitation when running on oil that I don't get when I'm on wood, that's the biggest reason I'm questioning if it should be there or not. The double pumping effect probably isn't terribly efficient either. So, should yank that pump?

 

[ewdudley]

Sounds right about not needing the oil boiler pump. You could start by simply disabling the oil boiler pump, the load circ should pump right through it well enough.

If the diverter valve is fully open from mix to hot then oil boiler pump can't pump at all.

If diverter valve is fully open from mix to cool then oil boiler pump is in series with load circ.

If diverter valve is half way open from mix to both hot and cool then I dunno.

(On the thermostatic valve it's true that the H side is the hot water, but on the valve itself it is the cold port, is that right?)

 

[kopeck]

Sounds right about not needing the oil boiler pump. You could start by simply disabling the oil boiler pump, the load circ should pump right through it well enough.

If the diverter valve is fully open from mix to hot then oil boiler pump can't pump at all.

If diverter valve is fully open from mix to cool then oil boiler pump is in series with load circ.

If diverter valve is half way open from mix to both hot and cool then some of the oil boiler flow will add to the load circ flow and some will short circuit back to the oil boiler.

(On the thermostatic valve it's true that the H side is the hot water, but on the valve itself it is the cold port, is that right?)

That's the way it's suppose to work, "recycling" hot water that didn't get used up on the first pass.

The H side is the outlet that goes back to the hot side of the manifold. I'm not sure if that answers your question.

I did think about disabling he circulator, I just wasn't sure how much of a strain it would up on the rest of the system.

K

 

[ewdudley]

That's the way it's suppose to work, "recycling" hot water that didn't get used up on the first pass.

The H side is the outlet that goes back to the hot side of the manifold. I'm not sure if that answers your question.

K

If it is a mixing valve in diverting configuration, then the physical port that is hot side for mixing purposes becomes the cool side for diverting purposes, and vice versa. If the mixing valve is labeled 'H', 'C', and 'M' then this could cause confusion. Hopefully they're just labeled 'A', 'B', and 'C', or '1', '2', and '3' and the installation instructions will take care of it.

 

[Fred61]

The mixing valve should go on the supply side and Hot boiler water should be plumbed to the H port, return water should be connected to the C port and the supply to zones should be connected to the M (mix) port. Dial on unit adjusts temperature of tne mix (M).
EDIT: Return water will then temper the hot boiler water.

 

[ewdudley]

The mixing valve should go on the supply side and Hot boiler water should be plumbed to the H port, return water should be connected to the C port and the supply to zones should be connected to the M (mix) port. Dial on unit adjusts temperature of tne mix (M).

(It's a diverting valve, not a mixing valve.)

 

[Fred61]

(It's a diverting valve, not a mixing valve.)

Well then I guess it should work as drawn if connected to the correct ports.

 

[kopeck]

I guess I should have said that my system works, it's more a question of the circulator.

Anyway...It's a diverting valve. If you would like to read up on it you can find the specs here:

(broken link removed to http://www.fpevalves.com/files/specsThermostatic%5C1010.pdf)

I had never seen one of these mentioned for hydronic applications but the folks at Revision have been using them for a while and they said they're pretty bullet proof.

The concept seems simple enough, why send hot water back to the boiler or storage when it can be used in a zone.

K

 

[kopeck]

And if you want a visual you can see the valve in the second picture of this post:

https://www.hearth.com/talk/threads/a-few-pictures-of-our-boiler-systems.75006/page-5#post-1302525

(The two pumps are in the picture as well)

K

 

[ewdudley]

I had never seen one of these mentioned for hydronic applications but the folks at Revision have been using them for a while

Tarm uses diverters in their reference designs systems with storage, except perhaps for those piped primary-secondary. Hydraulic separator also works quite well. "Simplest pressurized storage system" uses none of the above.

 

[kopeck]

Tarm uses diverters in their reference designs systems with storage, except perhaps for those piped primary-secondary. Hydraulic separator also works quite well. "Simplest pressurized storage system" uses none of the above.

Yeah but Tarm lists the Termovar product, what I meant was the FPE valve that I'm using.

None the less it seems to work. It was a bit of a pain to get piped in but you can tell when it's working.

K

 

[ewdudley]

Yeah but Tarm lists the Termovar product, what I meant was the FPE valve that I'm using.

None the less it seems to work. It was a bit of a pain to get piped in but you can tell when it's working.

That's a good find to have an alternative to Termovar and Danfoss. It should be possible to use for return protection as well I would think. Do you know the standard temperature settings available?

(And yes, I think you're right that the oil boiler pump can be eliminated.)

 

[kopeck]

This one is set to activate at 160 degrees if remember correctly. I'm pretty sure you can order them for different temps.

The only down part is the maximum inlet/outlet size is 1". The folks at Revision said they really hadn't had any issues with the smaller pipe size but if I had a big boiler and a large load I would probably look elsewhere.

K

 

[ewdudley]

This one is set to activate at 160 degrees if remember correctly. I'm pretty sure you can order them for different temps.

The only down part is the maximum inlet/outlet size is 1". The folks at Revision said they really hadn't had any issues with the smaller pipe size but if I had a big boiler and a large load I would probably look elsewhere.

The FPE chart shows a Cv of 16 or 17, whereas a 1.5" Danfoss has a Cv of 19 IIRC, so that's a nice free-flowing valve. I suspect the real restriction is the thermostatic element and necking down to 1" doesn't amount to much.

 

[kopeck]

I never looked up the CV for the Danfoss or the Termovar and I have to say I'm pretty surprised that the FPE fairs that much better at least compared to the Danfoss!

I bet's it's in the design of the body, even @ 1" the body of the valve is quite large, much more so then the other two brands.

K

 

[BHetrick10]

I understand how mixing valves work. What does this valve you are using do? What's it for? How is it plumbed in? Just trying to learn something new.

Thanks

 

[kopeck]

It's for redirecting heat.

Say you have a small zone that turns on, the water circulates through that zone but returns to the manifold at a pretty warm temp. Instead of sending, for example, 170 degree water back to the boiler to be heated again the valve closes and redirects the hot water back to the hot side of the manifold.

It's sort of the reverse of boiler protection.

K

 

[hiker88]

Kopeck,

I don't know if it is a question of removing the circulator in question, or only having it come on in certain situations. I used to have a circulator pump on the cold water return of my oil furnace as well. I removed it, and replaced it with pump c-1 in the attached diagram. My p-1 pump is an "Alpha" pump and the only thing it is connected to is a 110 outlet. The pump is set to "auto adapt". When a zone valve opens, pump p-1 runs as hard as it needs to - when there are no zones open it is idle.

p-1 is off a "t' with the left hand side going into a swing check. When the wood boiler is running, and there is a call for heat, I have three pumps running. c-3 on the wood boiler, c-1 and p-1. If I didn't have that "T' with swing check, I imagine I might have cavitation. However, that "T' lets the water that p-1 can't "pick up" flow on by, bypassing the zones, and then puts it back into the system. If that water is below 165, it is routed through storage and back to the boiler, if above 165 it goes back through c-1 and towards load again.

I've never had to use oil, but when I turn it on purposefully, Zv-1 is closed, c-1 is off, and the oil furnace just uses p-1.

When I have a call for heat and the wood boiler is off, zv-1 is on, c-3 is off, c-1 is on, and p-1 is on. This is all controlled by the Tarm "BLT' controller.

So depending on the scenario, I will have either 3, 2, or 1 pumps running.

 

[BHetrick10]

It's for redirecting heat.

Say you have a small zone that turns on, the water circulates through that zone but returns to the manifold at a pretty warm temp. Instead of sending, for example, 170 degree water back to the boiler to be heated again the valve closes and redirects the hot water back to the hot side of the manifold.

It's sort of the reverse of boiler protection.

K

I must have thick skull. Sounds like a mixing valve to me? Other than a mix valve will usually mix down a little even if turned up the whole way.

 

[ewdudley]

Sounds like a mixing valve to me?

You're right, it's a mixing valve, but the flow is the opposite direction, which makes it a diverting valve. So in the diagram flow is coming into the valve from the top, the opposite direction as would be the case if it was a mixing valve.

If water is hot, the valve port from the top to 'C' closes and the flow goes back around through the 'H' port.

If water is not hot, the valve port from the top to 'H' closes and the flow goes through the 'C' port.

 

[BHetrick10]

O ok I get it now. So you can use a regular mixing valve, or are they not ment to flow backwards.

So instead of the water getting mixed down with colder water say 180 down to 110 it would be taking that 180 and circulating in the loop until its down to 110 then returning it to the cold.

Numbers just an example. Sorry for hijacking

 

[ewdudley]

O ok I get it now. So you can use a regular mixing valve, or are they not ment to flow backwards.

Usually the spec sheet will say if it can be used for both mixing and diverting. Even some of the adjustable valves like the Taco 5000 series can be used for diverting. But as you suggest it is probably best not to assume that any given mixing valve can accept reverse flow.

 

[kopeck]

Sorry, late getting back. ewdudley seems to have everything under control.

BTW, I checked and my valve is configured for 170 F. So anything that temp or higher would be diverted back to the manifold.

K

 

[700renegade]

kopec, what $ do the FPE valves run and where did you purchase it? The Cv on them is fantastic - I wonder what fluid they used for the charts as they are designed for hot engine oil apparently. The Cv may even be higher than their chart for water ( obviously much lower viscosity than engine oil ).

 

[kopeck]

I don't know what the cost was, it was part of the "near boiler piping" package from Revision Heat.

I bet you could email them and they could tell you.

K