Constant Circulation system

Constant Circulation system

PostBy: jrv8984 On: Thu Jan 05, 2017 3:59 pm

So I'm starting a new thread, because my other one is a little bit all over the place
where to install circulators

Does anyone have any experience with Constant circulation?
Treat this as a new install, in a 200+ year old Farm house.

AHS 260 Coal boiler is in the Garage roughly 300' or less round trip (1.25" pex-al-pex is already in the ground with a total of about 16" of closed cell foam surrounding it)
Cast iron radiators (currently only one is plumbed, so I can easily undo it and plumb them anyway I'd like)
70 gallon Vaughn Top Performer indirect hot water heater in the basement.

Recommendations for the 4 way mixing valve to separate the boiler loop from the heating loop, DO I even need one, wont primary/secondary piping with closely spaced tees do the same thing

Recommendations for TRV's? for my radiators?

I assume for DHW I should plumb that off of the supply before the mixing valve if I use one.
I assume I should do the same for the basement dump zone.

Outdoor reset for the boiler, do I need an indoor reset for the house?
just going to plug the house circulator in and let her fly, should the boiler circulator do the same thing?

Any specific way to plumb the house, home run off of a manifold? other ideas?
I believe I'll need a pressure activated bypass for the heating loop?

Anybody have any diagrams of their systems?
Thanks
Last edited by jrv8984 on Thu Jan 05, 2017 8:32 pm, edited 4 times in total.
jrv8984
 
Other Heating: Blaze King Princess


Re: Constant Circulation system

PostBy: lzaharis On: Thu Jan 05, 2017 4:23 pm

When you refer to a constant hot water circulation system
you are actually referring to is a gravity flow hot water heating system.
The gravity hot water piping uses either the overhead or upfeed piping
method to heat a building up to three stories tall.
lzaharis
 
Stoker Coal Boiler: Keystoker KAA-4-1 dual fuel boiler
Coal Size/Type: rice
Other Heating: kerosene for dual fuel Keystoker

Re: Constant Circulation system

PostBy: lzaharis On: Thu Jan 05, 2017 4:52 pm

[quote="jrv8984"]Does anyone have any experience with Constant circulation?
Treat this as a new install, in a 200+ year old Farm house.




AHS 260 Coal boiler is in the Garage roughly 300' or less round trip
Cast iron radiators



How are the radiators piped? are they all piped the same way?







Unless you spend your money on the 15-25 dollar per foot logostor
oxygen barrier pex your going to have to mow the grass over the
trench in February.





Why are you not putting this boiler in the basement??



70 gallon Vaughn Top Performer indirect hot water heater


Recommendations for the 4 way mixing valve to separate the boiler loop from the heating loop?



Why do you wish to do this
when the boiler can heat your
domestic hot water as well??



Recommendations for TRV's? for my radiators?


There are many brands of trv's on the market



I assume for DHW I should plumb that off of the supply before the mixing valve.
I assume I should do the same for the basement dump zone.



[color=#000080]

do not assume anything!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Your getting way a head of yourself you need to diagram your existing plumbing
or have a plumber design your heating plant for you.


[color=#000080]


Outdoor reset for the boiler, do I need an indoor reset for the house?
just going to plug the house circulator in and let her fly, should the boiler circulator do the same thing?



You need to learn much more about coal boilers and their operation







Any specific way to plumb the house, home run off of a manifold? other ideas?
I believe I'll need a pressure activated bypass for the heating loop?

By pass loops are either manually adjusted flow control valves rated in gallons per minute or simple ball valves. dump zones when properly wired and plumbed are temperature activated and dump in the house loop, a basement or a garage in these three exmples.




Anybody have any diagrams of their systems?

If you purchase the two paperbacks I suggested you will learn a lot about hydronic heating and hot it has been done in the past and how it is done now.


Those books are a good investment for you so you can learn about hot water heat and steam heat. Buy the books, read them several times then put your system down on paper and then come back and ask questions.

I would also strongly suggest that you purchase this boiler from a dealer/plumber that will install it for you as well.










Before you go any further;

Please purchase a copy of "Classic Hydronics" and a copy of "Pumping Away" written by Dan Holohan from Barnes and Noble, Amazon or http://www.dansbooks.com

These paper back books will explain everything you need to know about hot water heating.
and will prevent you from making costly dangerous mistakes.
Dan writes his plumbing books for both the lay person and the plumber alike making it very easy to understand what he is talking about in his writing









lzaharis
 
Stoker Coal Boiler: Keystoker KAA-4-1 dual fuel boiler
Coal Size/Type: rice
Other Heating: kerosene for dual fuel Keystoker

Re: Constant Circulation system

PostBy: coaledsweat On: Thu Jan 05, 2017 5:42 pm

Are you referring to this? Very trendy in Europe, low temperature modulated heating. I looked at it years ago and decided not to bother.

https://www.google.com/url?sa=t&source= ... izQyOP5wng
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Constant Circulation system

PostBy: jrv8984 On: Thu Jan 05, 2017 5:48 pm

Yes, that's what I am talking about, or something very similar.
I'm not talking about a gravity system.

I don't mind being the 1st one to give it a try if it will work.
jrv8984
 
Other Heating: Blaze King Princess

Re: Constant Circulation system

PostBy: McGiever On: Thu Jan 05, 2017 6:21 pm

Like the 4-way modulation there is another cc where controls inject full boiler temp water via a smaller pump w/ it's speed varied in order to inject just enough to meet set point dictated likewise by a outdoor reset or the like.

Tekmar Controls take care of this...and so does Taco by re-branding their logo to the Tekmar builds.
McGiever
 
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Coal Size/Type: PEA / ANTHRACITE
Other Heating: Ground Source Heat Pump
Stove/Furnace Make: Hydro Heat /Mega Tek

Re: Constant Circulation system

PostBy: CoalisCoolxWarm On: Thu Jan 05, 2017 7:59 pm

More details here, including request for solar powered system: http://nepacrossroads.com/about42682.html
CoalisCoolxWarm
 
Stoker Coal Boiler: Keystoker KA-6
Hand Fed Coal Furnace: old Sears rebuilt, bituminous- offline as of winter 2014
Coal Size/Type: Anthracite Buckwheat
Other Heating: Oil Boiler

Re: Constant Circulation system

PostBy: Scottscoaled On: Thu Jan 05, 2017 8:19 pm

I think you would be better off without the drama of the 4 way and associated controls. They have to be pretty pricey. I think a better alternative would be to use the individual TRV's in each room and supply those with a high head pump at the boiler. One of the variable speeds. The boiler temp would be controlled by an outdoor reset controller such as a Tekmar boiler controller 261 single stage or a 262 two stage. An inexpensive solution would be to lose the TRV"S and variable speed pump and use a high head pump like a B & G NRF-25. You would have to really do a good job balancing out your system. It probably would take a little bit of trial to get the right reset curve on the boiler reset controller.
Scottscoaled
 
Stoker Coal Boiler: EFM 520, 700, Van Wert 800 GJ 61,53
Baseburners & Antiques: Magic Stewart 16, times 2!
Coal Size/Type: Lots of buck
Other Heating: Slant Fin electric boiler backup


Re: Constant Circulation system

PostBy: jrv8984 On: Thu Jan 05, 2017 8:40 pm

One idea I was thinking of was to use a large pump at the boiler, keep the TRV's and just provide some kind of bypass so that it wouldn't dead head against the TRV's.
jrv8984
 
Other Heating: Blaze King Princess

Re: Constant Circulation system

PostBy: lzaharis On: Fri Jan 06, 2017 11:18 am

jrv8984 wrote:One idea I was thinking of was to use a large pump at the boiler, keep the TRV's and just provide some kind of bypass so that it wouldn't dead head against the TRV's.

===========================================================================

Please invest in those two books as Dan Holohan also describes the European heating standards as well.

Pumping away from the boiler to the heating load by mounting the circulator on the top of the steam chest helps remove the air bubbles in the water much more quickly too.

Part of me wants to ask, why are you making more work for yourself when you can simply run the boiler at 160 high 120 low and heat the entire home that way.

As Scottscoaled said the NRF 25 circulators are very good hydronic heat pumps . I have an NRF25 without the check valve running on speed one at about 12 gallons per minute.

I regulate the temperature with the thermostat leaving my triple aquastat set at 160 high 120 low and the high limit water temperature at the steam chest always stays around 160+- and takes very little time and energy to heat the cooler return water back to 160 degrees.

I have been doing this with my heating system in my home since late October and making hot water with much less work.
lzaharis
 
Stoker Coal Boiler: Keystoker KAA-4-1 dual fuel boiler
Coal Size/Type: rice
Other Heating: kerosene for dual fuel Keystoker

Re: Constant Circulation system

PostBy: jrv8984 On: Fri Jan 06, 2017 11:48 am

No house thermostat is needed for this type of system.

If I just let the boiler pump fly, is it best to use circulators for the indirect and dump zone, or should zone valves be used? Circulators seem like a better idea to me.

Unless I use a Mixing manifold (LLH) I figure I would have my boiler loop and then tee off for the indirect then Dump Zone and lastly tee off to a radiant manifold/s out to my radiation.

Only need to wire in the dump one and indirect, in this case should that be to a zone controller taco 502, or?
jrv8984
 
Other Heating: Blaze King Princess

Re: Constant Circulation system

PostBy: lzaharis On: Fri Jan 06, 2017 12:41 pm

jrv8984 wrote:No house thermostat is needed for this type of system.

If I just let the boiler pump fly, is it best to use circulators for the indirect and dump zone, or should zone valves be used? Circulators seem like a better idea to me.

Unless I use a Mixing manifold (LLH) I figure I would have my boiler loop and then tee off for the indirect then Dump Zone and lastly tee off to a radiant manifold/s out to my radiation.

Only need to wire in the dump one and indirect, in this case should that be to a zone controller taco 502, or?

===========================================================================
Your wasting heat with a constantly running circulator. The other thing is that the European safety laws for homeowners boilers mandates a "very low boiler maximum operating temperature/HIGH LIMIT temperature to reduce the possibility of scalding burns from hydronic heat pipe leaks and ruptures.

If you plumb the single circulator, the TRV's and the radiators correctly you will have no issues. Dan Holohans books classic hydronics and Pumping Away talk about the TRV's a lot and show how they work.

Please buy those books and read them. You will be way ahead and save lots of money and have a warmer home burning less coal too.
Yoou should also purchase "Greening Steam" by Dan Holohan as well to examine steam as an option.

===========================================================================
You may find that an AHS 130 making steam and domestic hot water in a one pipe system in your basement is more than enough of a boiler to do the job you want rather than have all the extra controls, solenoid valves and wiring as each radiator will have its own thermostat mounted on the vent of the radiator and they have been in use for a very long time now and work very well.
lzaharis
 
Stoker Coal Boiler: Keystoker KAA-4-1 dual fuel boiler
Coal Size/Type: rice
Other Heating: kerosene for dual fuel Keystoker

Re: Constant Circulation system

PostBy: jrv8984 On: Sat Jan 07, 2017 12:30 pm

Anybody else with constructive ideas OTHER than purchase a boiler from a heating specialist, install it in my basement, convert to steam, or install logstore because I'm going to be heating the ground all winter.

PLEASE read my original post!

The point of constant circulation is that you only have one to a few circulators running. the boiler is not idling and then a heat call makes it burn hotter than hell. It keeps things relatively constant, and the TRV's modulate the continuous flow through the radiators so that they maintain a constant temp. Ideally it is never dumping cold water back into the boiler, you never have temperature fluctuations in the house. This should save fuel.

When you look at having a dozen circulators in your home that will be running at least the equivalent of 2 hours a day, if not more, you break even or save on electricity.

If I'm wrong someone with experience with this type of system please tell me?
jrv8984
 
Other Heating: Blaze King Princess

Re: Constant Circulation system

PostBy: CoalisCoolxWarm On: Sat Jan 07, 2017 12:47 pm

jrv8984 wrote:Anybody else with constructive ideas OTHER than purchase a boiler from a heating specialist, install it in my basement, convert to steam, or install logstore because I'm going to be heating the ground all winter.

PLEASE read my original post!

The point of constant circulation is that you only have one to a few circulators running. the boiler is not idling and then a heat call makes it burn hotter than hell. It keeps things relatively constant, and the TRV's modulate the continuous flow through the radiators so that they maintain a constant temp. Ideally it is never dumping cold water back into the boiler, you never have temperature fluctuations in the house. This should save fuel.

When you look at having a dozen circulators in your home that will be running at least the equivalent of 2 hours a day, if not more, you break even or save on electricity.

If I'm wrong someone with experience with this type of system please tell me?


Frustrated? Don't be.

The reason you are getting advice about other products and solutions is because your requirements and conditions are changing, for which there are better solutions. You don't have to follow those suggestions, but it would be wise to investigate them and then see the reasons they are "better" and the compromises you may get by not using them.

If you can then accept those compromises, not only will you be going in with your eyes open, but you also have the opportunity to mitigate them. Heck, if it costs you 10% more fuel and you can live with that, it's a WIN ;)

In your other thread, it looked like you had some good options, then you threw in a "solar only" requirement. Okay, very low power requirements often require performance compromises and sometimes "old style" systems.

In addition, having a "build as you go" system (like many of us), you don't really have the benefit of doing it all at once and creating a fully balanced system- even if you had super-duper-expert help. It will be a moving target. Maybe you're okay with that, but folks here are trying to give you a heads up about it so you're not frustrated down the road.

Personally, once you went with the uber-low-power requirements of solar and only one or two circulators, I took a step back to let some others with more experience in that area step forward. And they did 8-)

Doesn't mean I don't agree or disagree, but we try to be pretty "responsible" when it comes to heating recommendations. We all know your home, your family, possibly even your life is on the line when it comes to HVAC systems and we're a pretty cautious bunch there- as you should expect. Anyone who isn't really shouldn't be heeded.

Here's a suggestion that might help.

Now that you have gotten some really good design tips, cautions, suggestions, etc with your initial scatter-shot, take that info and refine your goals and system. Separate the requirements from the wants.

Part of that should include a HeatLoad/HeatLoss calculation, and I'd suggest the Taco software that does a decent job of calculating flows, design temp requirements, etc. It takes some time, but is far cheaper/faster than experimenting physically, then finding out you have a critical problem somewhere.

Hopefully this helps!
CoalisCoolxWarm
 
Stoker Coal Boiler: Keystoker KA-6
Hand Fed Coal Furnace: old Sears rebuilt, bituminous- offline as of winter 2014
Coal Size/Type: Anthracite Buckwheat
Other Heating: Oil Boiler

Re: Constant Circulation system

PostBy: jrv8984 On: Sat Jan 07, 2017 1:21 pm

I don't have a problem with constructive help, but not reading my original post thoroughly and then telling me to basically undo things is not helpful. The boiler is in the garage, the masonry chimney is in the garage. I literally cannot put the boiler in the basement for numerous reasons. I am not going to go and buy another boiler. Why would I want to use logstor, when I already have larger diameter pipe in the ground with 16" of spray foam around it? it was cheaper and a better way to do it any way you look at it.

That being said back to business.

The beauty of working part time for a solar panel installer is that I can get the system for a little more than cost, and it's going to be a very large system, I just havent gotten around to it. But conserving power anywhere I can is always on my mind.

I have a general idea of the heat loss of my house, but specifics can't be obtained when you can see daylight through your walls. Believe it or not the house is warmer after ripping out the hack job of insulation and drywall the previous owner did and repointing the interior of the stone walls. Obviously I'm not finished only about a 3rd of the way done.

As simple as it would be, I just don't want to have a dozen pumps running, if I can cut that # down to a few. And the wife won't allow an Ecm circulator in the house, I could put one on the boiler, but I don't know if it's really necessary if I can just use a pump and a bypass valve. She really likes the idea of constant temp throughout the house and the TRV's on the radiators
Last edited by jrv8984 on Sat Jan 07, 2017 2:27 pm, edited 1 time in total.
jrv8984
 
Other Heating: Blaze King Princess