Help updating radiant heat system.

seanbeck1

Hi guys. New to this forum and I’m looking for some expert advice regarding the adjustment of my current radiant heat setup. I’m a licensed plumber/gas fitter but I work all ICI so I have decent knowledge or radiant heat systems but not as vast as the experts here.

I currently have a Slant Fin gas boiler supplying cast iron radiators via 2” main heating lines in my basement. The system is zoned with zone valves and a single circulating pump.

Zone 1 - Basement (2 Rads)
Zone 2 - Main floor and second floor

I want to split zone 2 which will give me three zones and isolate each floor individually. Im going to be pulling down my basement ceiling to give me access to the risers feeding the rads on the main floor and second floor. I will be removing the 2” steel pipes and running Uponor from my risers to where my boiler is located.

I’m hoping guys can offer me advice on some components. I plan to add a low loss header so I’ll need advice on sizing my boiler pump and radiant pump. Also looking for advice on whether I should use zone valves only or zone valves with manifolds feeding each rad individually so I can monitor flow rate.

Boiler - 100K BTU

Basement Rads -
One steel low profile
One custom copper radiator

Main Floor Rads-
4 Cast iron

Second Floor Rads
4 Cast Iron Rads

EdTheHeaterMan

Review this text. http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf

Everything you need to know is in here. B&G parts are listed since they paid to publish, but you can substitute Taco or Armstrong or any other brand

Pay special attention to pipe sizing and gallon per minute rates for zone valves v. circulator zoning. The zone valve will reduce the amount of flow (amount of heat capacity) per branch. This is covered at the bottom of page 17 and continuing on to page 18.

seanbeck1

> @EdTheHeaterMan said:
> Review this text. http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf
>
> Everything you need to know is in here. B&G parts are listed since they paid to publish, but you can substitute Taco or Armstrong or any other brand
>
> Pay special attention to pipe sizing and gallon per minute rates for zone valves v. circulator zoning. The zone valve will reduce the amount of flow (amount of heat capacity) per branch. This is covered at the bottom of page 17 and continuing on to page 18.

Thanks for the information. Definitely helped with the sizing for zone valves. I want to use zone valves because I have two in place already and I have a couple of new ones that I acquired so it will save me $$$.

I did a quick sketch of my thoughts. Maybe somebody could let me know if and where I’ve gone wrong and correct me.

I want to have three zones (basement, main floor and second floor). Second floor and main floor each have 4 cast iron Rads. basement has two rads. I’ll be running Uponor from the rads ideally to a manifold with balancing valves which I’ll either make myself or buy depending on cost.

EBEBRATT-Ed

@EdTheHeaterMan

That's pretty slick! That has @DanHolohan written all over it. If he did not write that I'll eat my hat!!

hot_rod

I prefer the zone valves on supply for 100% protection against ghost flow. A zone valve with a 7.5 Cv will give you adequate flow, plenty for 3/4 or 1” zones. A delta P circulator works well with zone valves

seanbeck1

> @hot_rod said:
> I prefer the zone valves on supply for 100% protection against ghost flow. A zone valve with a 7.5 Cv will give you adequate flow, plenty for 3/4 or 1” zones. A delta P circulator works well with zone valves

Thanks for the input. So zone valves on supply side and balancing valves on return?

Would you recommend a Delta P pump for both boiler loop and primary loop?

Thanks

DanHolohan

@EBEBRATT-Ed, no need to eat your hat. ;-)

EdTheHeaterMan

EBEBRATT-Ed said:

@EdTheHeaterMan

That's pretty slick! That has @DanHolohan written all over it. If he did not write that I'll eat my hat!!

I received a personal response from @DanHolohan regarding this text from another post. YES he did write this original draft and sold it to B&G. The PR made my day week

EdTheHeaterMan

Delta P pump is a good idea. Full port ball valves are also a good idea if the existing rad valves don't work. Balancing the system may be time-consuming with ball valves. As you close off one valve all the remaining open valves will get more flow. Each adjustment will make changes in the other radiators. Just make sure you don't deadhead the circulator pump. That is covered on the bottom of page 20

seanbeck1

> @EdTheHeaterMan said:
> Delta P pump is a good idea. Full port ball valves are also a good idea if the existing rad valves don't work. Balancing the system may be time-consuming with ball valves. As you close off one valve all the remaining open valves will get more flow. Each adjustment will make changes in the other radiators. Just make sure you don't deadhead the circulator pump. That is covered on the bottom of page 20

Do I have to worry about dead heading the pump if my zone valves are controlled by the Taco ZVC? Pump turns on and off when a zone opens/closes.

Should I also worry about glue gas condensation for my conventional cast iron boiler in fall/early winter when there may not be a continuous call for heat?

hot_rod

Yes a return temperature protection valve would be a wise investment IF that boiler runs for extended periods below 130 return. The best practice is within a 10 minute run cycle the boiler should be up above 130f return.

Here is an example. Standard circ on the boiler, delta P on zone valves. Caleffi Quicksetters on returns if you want flow balance and indication.

seanbeck1

> @hot_rod said:
> Yes a return temperature protection valve would be a wise investment IF that boiler runs for extended periods below 130 return. The best practice is within a 10 minute run cycle the boiler should be up above 130f return.
>
> Here is an example. Standard circ on the boiler, delta P on zone valves. Caleffi Quicksetters on returns if you want flow balance and indication.

Thanks very much for your input. I don’t have any low temperature heat emitters. Everything is cast iron radiators. I’d just be worried about cold start-ups if there hadn’t been a call for heat for a few hours.

hot_rod

seanbeck1 said:

> @hot_rod said:

> Yes a return temperature protection valve would be a wise investment IF that boiler runs for extended periods below 130 return. The best practice is within a 10 minute run cycle the boiler should be up above 130f return.

>

> Here is an example. Standard circ on the boiler, delta P on zone valves. Caleffi Quicksetters on returns if you want flow balance and indication.



Thanks very much for your input. I don’t have any low temperature heat emitters. Everything is cast iron radiators. I’d just be worried about cold start-ups if there hadn’t been a call for heat for a few hours.

You can either calculate that potential if you know the volume mass and heat output of the radiators, based against boiler output. If the boiler was oversized to the load and connected emitters it has probably run okay. That is commonly the case, oversized boilers.
Or just watch the boiler on a cold start condition, and on low load, short cycle conditions and see how quickly it warms up.

Usually there will be signs of a boiler running extended cold return conditions. Rust and corrosion around the diverter hood and vent piping, rust debris under the burners, staining on the roof near the vent termination, etc.

EdTheHeaterMan

to answer your Q. about Dead Heading Pump: the Taco ZVC will only allow the pump to operate on a call for heat from a zone valve (assuming proper wiring). My concern is using ball valves to balance the individual radiators... make sure someone does not close all the vales completely and attempt to start the pump.

I just want to be clear. Some posting individuals are not as mentally gifted as others. Balancing with ball valves is the poor man's way to accomplish this. Circuit setters or Thermoflow Balancers are a better way... but WAY overkill for your project

hot_rod

> @EdTheHeaterMan said:
> to answer your Q. about Dead Heading Pump: the Taco ZVC will only allow the pump to operate on a call for heat from a zone valve (assuming proper wiring). My concern is using ball valves to balance the individual radiators... make sure someone does not close all the vales completely and attempt to start the pump.
>
> I just want to be clear. Some posting individuals are not as mentally gifted as others. Balancing with ball valves is the poor man's way to accomplish this. Circuit setters or Thermoflow Balancers are a better way... but WAY overkill for your project

Perhaps the most common balance valve you see installed is the popular B&G circuit setter, it is a ball valve. The Thermflow is a butterfly style maybe even less flow friendly

I agree a globe style valve is perhaps the best valve style for accurate, lineal balancing

Avoid chocking down a ball style valve more than 45%, a crummy flow path is presented

seanbeck1

How does this look? Still have to add drain, auto fill, backflow and air vents.

hot_rod

So the flow is clockwise, according to the red and blue valve handles on the manifold? The circulator is pumping up?

Ideally the air purger would be at the hottest point in the piping right near the supply coming out of the boiler or heat source.
That type of purger likes to have 18" of straight pipe upstream to work best.
You could add a vertical type micro bubble air sep on the supply just to the left of the circulator on the supply.

Something missing at the very bottom, or did you run out of space for the last manifold?

seanbeck1

> @hot_rod said:
> So the flow is clockwise, according to the red and blue valve handles on the manifold? The circulator is pumping up?
>
> Ideally the air purger would be at the hottest point in the piping right near the supply coming out of the boiler or heat source.
> That type of purger likes to have 18" of straight pipe upstream to work best.
> You could add a vertical type micro bubble air sep on the supply just to the left of the circulator on the supply.
>
> Something missing at the very bottom, or did you run out of space for the last manifold?

Correct, flow is clockwise with the pump pumping up. Was planning on adding an air vent in the top right corner.

Nothing missing at the bottom. I’ll be drilling through the plate and feeding all heating lines through the back so everything will ‘90’ towards the diamond plate.

hot_rod

seanbeck1 said:

> @hot_rod said:

> So the flow is clockwise, according to the red and blue valve handles on the manifold? The circulator is pumping up?

>

> Ideally the air purger would be at the hottest point in the piping right near the supply coming out of the boiler or heat source.

> That type of purger likes to have 18" of straight pipe upstream to work best.

> You could add a vertical type micro bubble air sep on the supply just to the left of the circulator on the supply.

>

> Something missing at the very bottom, or did you run out of space for the last manifold?



Correct, flow is clockwise with the pump pumping up. Was planning on adding an air vent in the top right corner.



Nothing missing at the bottom. I’ll be drilling through the plate and feeding all heating lines through the back so everything will ‘90’ towards the diamond plate.

Looks good. You probably have air vents or manual vents on the radiators? So air removal should not be much of an issue.

seanbeck1

> @hot_rod said:
> (Quote)
>
> Looks good. You probably have air vents or manual vents on the radiators? So air removal should not be much of an issue.

Thank you. Yeah my radiators have manual air vents.

My boiler has its own circulator wiring harness. Should I let my boiler control the circulator or let the ZVC control my circulator?

seanbeck1

seanbeck1

That’s how it all turned out anyway lads

STEVEusaPA

Looks nice! Just wish you would’ve used a MBR instead of the air scoop.
Where’s the expansion tank?

seanbeck1

STEVEusaPA said:

Looks nice! Just wish you would’ve used a MBR instead of the air scoop. Where’s the expansion tank?

Expansion tank is in the ceiling. There is a tee after the automatic feed valve that ties in the expansion tank. Couldn’t afford a MBR. 

hot_rod

All that copper scrap in the truck could have bought the air sep

PC7060

sorry to reveal my ignorance but what does the "MBR" acronym stand for?

mattmia2

hot_rod said:

All that copper scrap in the truck could have bought the air sep

Or make one of the manifolds with tees.

MBR: Microbubble resorber air separator.

GroundUp

A sweat MBR is $85 versus $35 for the scoop and adapters. Pretty sure it was in the budget, but it looks great nonetheless and will do a great job for you.