Fixing self inflicted heat imbalance after insulating attic

Misplaced_Yankee

System is two pipe gravity fed hot water and works well.  2 story house. 

After reading through Dan’s blog exposition I realized that I created an

imbalance in the system by thoroughly insulating the attic; basically second

floor is too warm vs. first floor.





 





Question:  In an 80+

year old system (boiler about 40-50 years old) is it less disruptive install thermostatic control valves TCV

in the existing valves (such as Macon E-Z fit conversion kit) or installing

inlet orifices TRV?  I believe that

installing the orifice requires opening the union, moving the radiator,

installing the orifice, and then praying that it all goes back together.  While the TCV will probably be more expensive

at least I’m only working on the guts of the radiator valve.





 





Living in Memphis the first reaction of any plumber is

either “why do you want to work on that old thing?” or “you need a new boiler

and that has to have a circulating pump.” I figure I’m largely on my own in

this project.  Any sage advice or

northern plumbers making a trip south?

nicholas bonham-carter

gravity imbalance

couldn't those valves on the rads be used to throttle them down [flow-wise] so as to put out less heat?--nbc

Misplaced_Yankee

Manual valves not intended for flow control?

From Dan's book, the basics of the radiator valve is to be open or closed.  Partially throttling down the valve makes very little difference in the actual heat output. (closing valve 90% will only reduce heat output by about 10%).

On a more trial and error approach, I tried your suggestion and it didn't seem to make much difference, unless I went too far and actually closed the valve.

Thanks for thinking through the problem with me .  any additional thoughts would be appreciated

mark schofield

radiator cover?

could you experiment with a reflective insulating cover for the radiators and if the heat emitted is lessened, then find a permanent and attractive solution. 

Mike Kusiak_2

Throttling the valve

Throttling the radiator valves should have the same effect as installing the orifice plates. Both will restrict the flow and reduce the heat output. Remember that the big cast iron radiators have a lot of thermal mass, so it will take a long time for their temperature to change after adjusting he valve. You might not notice the effect until several hours later.



I would try continuing to close the valves until you notice a change in upstairs temperature. If you install TRV's, they will be doing exactly the same thing, only they will automatically sense temperature and close to throttle flow accordingly.

pat_3

balancing rads on the cheap

this is  the cheapest way i could think of to fix what tou are dealing with....how about draining the system and then refill it   without bleeding the radiators all the way on the rads that you want to reduce output on.just my 2 cents,hope it helps.

Misplaced_Yankee

Throttling back radiator valves

After last night's post i turned one of the valves all the way off, using a wrench to make sure it was snug.  Well I've now discovered that that valve doesn't close completely, but the radiator was cooler vs. others.  I'll try a different radiator tonight.  I agree that the heat dwell time is significant so overnight seems like a fair test cycle.  Thanks,

Misplaced_Yankee

Balancing on the cheap let induced air be your friend

Pat,



This sounds like a novel solution that might just work.  Since all the radiators that I want to "reduce output" are on the second floor I could try to drain enough water to empty the upstairs radiators and still leave the water in the down stairs radiators. When refilling I would only have to fiddle with the bleeding of the upstairs radiators. 

All the radiators are bottom/ side inlet and outlet so I assume that means leaving a lot of air in the upstairs radiators.

Any one else have a comment on this plan of attack?

icesailor

Bad third world fix

I don't consider that a good idea because the air will be absorbed by the water over time and will keep the boiler water saturated with oxygen for a long period of time and causing come level of corrosion.

JMO

LarryC

Corrosion until O2 is all absorbed.

Ice,

 

I agree the corrosion will continue until all of the O2 is consumed.  How long will that take?  After the O2 is consumed, won't the corrosion stop?