Hodgepodge of Radiators!! Suggestions

Sigmaster

Top 'o the mornin' gents!



First, thanks for all or the valuable information on this website I have improved my one pipe steam system greatly. You guys are great!



Now...the issue at hand. I purchased a home about a year ago not knowing much (anything) about steam systems. I have in the wall convectors on my first floor (not cast iron, but copper pipe with fins) where my thermostat is located. On my second floor I have cast iron baseboards in the bedrooms, and a cast iron column style radiator in the bathroom. Anyone guess my problemo??



I was thinking of converting my convectors downstairs to cast iron convectors using the same housing and covers. What do y'all think about that? I believe Governale makes something that would work. Any pitfalls? Bottom line, I want to be 100% cast iron for evenly heating the house. I am open to all suggestions.

crash2009

I'll take a guess

The convectors are working good, as a matter of fact too good.  The thermostat shuts down the boiler before the rest of the house gets enough heat.  If that is the problemo, I think we can come up with a fairly inexpensive solution. 

Sigmaster

Hmmm

The issue is the quick heating and cooling downstairs with the slower heating upstairs. Upstairs slowly becomes warm, and then too warm... with the downstairs swinging from warm to cool very quickly with the boiler cycling a lot. Thermostatic valves upstairs could help I suppose. I have changed my thermostat to a programable one and set it to 3 cycles per hour to start this season off we'll see if this helps with the constant on and off of the boiler.



Crash, what are you thinking compadre?

crash2009

Ventrite #1

Well, originally I was thinking that the venting on your convectors is too fast.  I have a convector which is the same type of construction as you described yours.  My thermostat is installed very close to my convector.  The problem I had early last winter was the convector got so hot that the thermostat shut the boiler before the rest of the house got warm.  I tried many different kinds of vents on my convector, even a Hoffman 40, with no success.  Finally someone here told me to choke the hell out of it with the slowest vent I could get.  I found a Ventrite #1 in the box of old vents that came with the house.  Put it on, sealed the threads, etc.  The Ventrite #1 is adjustable from 1-8.  (1 is off), (2 is .020 CFM) (3 is .036 CFM) So anyway I shut the vent all the way off, and then went downstairs and turned the boiler on, then went upstairs to adjust the Ventrite on the convector.  I put my left hand on the convector near the Ventrite, and my other hand on the adjustment wheel.  I opened the adjustment wheel just enough to warm up my left hand.  That method of choking cured my problems.  The setting I ended up with was between 2 and 3.  Just to give you an example of how slow that is, a super slow Hofman 40 is .067.  My convector is set to less than .036 CFM.

You probably should look at all the radiator venting.  Here is the first step.



http://www.heatinghelp.com/products/Steam-Heating-Books/25/146/Balancing-Steam-Systems-Using-a-Vent-Capacity-Chart-by-Gerry-Gill-and-Steve-Pajek

By the way the cycles per hour on your thermostat should be set to one per hour.  If the thermostat can't do that chuck it and get one that can.

Sigmaster

Cast Iron Convectors?

Upstairs I have Hoffman 40's and a 41 (cast iron rads), and downstairs on the convectors I have a Gorton C on my large convector (living room), a Gorton 6 on both bedroom radiators and a Hoffman 41 in the bathroom near the thermostat.  Upstairs has no problem heating up, but it just gets too warm sometimes.  Balancing a system with different types of rads is no bueno.



I can change the cycles on my thermostat lower, but I was going to test the cycles starting at 3 with these convectors since they heat and cool so quickly.  I would like even temps without peaks and valleys downstairs.  I just installed the new thermostat last week (Honeywell 7600).   Last winter my boiler was cycling way to much (much more than 3) on the really cold days.



I think I need to change my down stairs rads to cast iron to match upstairs (at least in the living room).  The convectors downstairs heat up and cool to quickly, while upstairs stays toasty to hot. 



Anybody have experience with cast iron convectors?

crash2009

Sig

I understand what you are trying to do.  3 cycles/hour, just give the convector a little bit 3 times.  Good theory but its gonna cost you a lot of fuel.  A steam system is like a baloon, blow it up and let it sit.  If the convectors are getting too hot, slow the venting.  Don't replace the car because it has a flat tire.



You need to set the cycles to 1 for steam.  http://customer.honeywell.com/techlit/pdf/PackedLit/69-2206ES.pdf  page 18

Sigmaster

Aight

So I set the cycles to 1, let see how she works.





Has anybody used cast iron convectors here?



Like these  http://www.governaleindustries.com/convectors.cfm

Dave in QCA

Another perspective...

I have been thinking about this post for a while and decided to take the time to reply.



Copper fin tube radiation and cast iron radation perform VERY differently.  Most of the rules that apply to cast iron do not apply to copper fin tube.  Tekmar controls, in their recommendation for setting up their model 279 steam boiler control state that cycle times should be set for 1 hour for cast iron radiation and for 20 minutes for copper fintube.  Why would that be?



Cast iron radiators have hundreds of pounds of mass and take a considerable amount of steam to heat them up.  They act as an enormous heat sink and when the boiler shuts off, the portion of the radiator that was heated, whatever that might be, continues to give off heat for nearly an hour.  Thus, from a comfort standpoint, you cannot tell that the boiler is only running once an hour because the heat continues to flow from the radiator.  Comfort is optomized and that leads to lower operating costs because there is no overheating of space and wasted energy.  Standby losses my also be reduced.



When steam arrives at a copper fintube unit, there is only a tiny fraction of the mass of a cast iron radiator, and a very small amount of air volume in the tubes.   Thus, the convector will fully heat very quickly.  Within a very short time, a convector will be performing at 100% output.  When the boiler shuts off, within a very short time, there will be no residual heat, because there is almost no mass and the output will drop to 0.  The heat output of a convector will operate in an on/off mode depending whether steam is up, or not.



Problems arise when portions of a building are modernized, and some cast iron is replaced with copper fine tube.  One unit here or there is not a huge deal.  Crash, your bathroom convector is probably nice because I am guessing that it heats up real fast!  But 50 minutes later, I am guessing that it would be nice if there was still a little bit of heat coming out instead of a stone cold convector?



Sigmaster, my approach to your situation would be to set the cycles for either 2 or 3 per hour.  I would not do anything to slow down the venting of the convectors.  There is little air volume, so even a relatively slow vent will allow the convector to fully heat.  The cast iron on the second floor, I would experiment with some reduced or restricted venting.  2 or 3 cycles an hour will not have a large negative effect on the cast iron performance.  What you will notice is that a smaller portion of the radiation will heat up, but it will do so 2 or 3 times per hour, thus a smaller portion of the radiation will be staying hotter over the course of an hour.  



What you want to achieve is even heat delivery over the course of an hour in both the first and second floor rooms.  This will happen through 2 or 3 on cycles of the convectors where they will briefly be putting out 100% capacity.  The cast iron on the second floor will putting out only a small portion of its full rated capacity, but it will be doing more or less continuosly, over the course of the hour.  Balancing the two is the challenge.



You are right, this is a difficult situation and requires a good deal of experimental adjustment to achieve good temperature balance in your home.  But, you probably can get it balanced.  Cast iron elements for your convectors would be a good solution.  I have surveyed and balanced a building where the original cast iron radiators were still in place on the second floor.  The first floor had newer semirecessed convectors with cast iron elements installed under every window.  The performance was quite good and the 2 floors were balanced.  Cycles were running at 1 per hour, more or less.



Keep us updated with your observations and progress.

Sigmaster

Thanks for the reply

Last winter my boiler was cycling on and off so way too much and had a multitude of problems.  I have since upgraded the thermostat, installed main line vents, bought main line insulation (en route), and replaced every single radiator vent.  The vents upstairs are pretty slow, (hoffman 41 or 40's) and the vents downstairs range from faster to moderate (gorton C, gorton 6).  I live on the 1st floor and have a tenant renting upstairs so if it is too hot up there it's not a huge issue, but I would like to master this system for my own personal satisfaction.



Based on my research I think I have two options.  Cycle from 2 -3 as you suggested and as I initially was going to experiment with, or upgrade downstairs to cast iron.  I came across a good deal on tube style cast iron radiators and may pull the trigger on a few of them and test them out.  Unfortunately I would have to calculate the heat loss for the rooms which I am having a little trouble with.



Living room kitchen combo, north half of first floor = 1 larger radiator in living room under bay windows on east side of house (nothing in kitchen) ~ 24 x 12



Two bedrooms both approximately 10 x 11 on the south side of the house (two normal size windows in each room.



Small bathroom 8 x 6 on west side.

Rod

TRVs?

If it gets too hot upstairs you could consider using TRVs on the radiators. If you do, be sure to get the model for one pipe steam. My upstairs bedrooms get too hot and I use TRVs to keep them cool at night.

- Rod

Tim_Hodgson

Cheap Fix

Restrict the air flow through the convectors until both floors are comfortable. I would go to a sheet metal company and have them cut some 4 foot by the width of the fins dimension and then cut them at 12' long. You can overlap the sheetmetal and make a baffle any length you need. You will have to experiment until you find the correct amount. I would start by blocking 70% of the air and decreasing it as each room gets too cold.

Good luck,

Tim

Sigmaster

Got some rads

I managed to source 3 cast iron rads for $200.  Two are 25" high, 4 tubes, 10 sections, and one is 25" high, 4 tubes, and 20 sections.  The smaller ones I believe will be good for my two bedrooms (~11 x 11ish) and the larger one will go in my living room / kitchen ( ~22 x 12).  Does anybody think this is too much / too little radiation for the rooms?  I calculated a rough edr / heat loss and it seems to be close.



Is there any rule of thumb on near radiator piping?  The pipe that comes up through my floor is too close to the wall to fit these rads so I was going to point the valve away from the wall (instead of along the wall) and install a 90 degree elbow to the rad.  Make sense?

Sigmaster

Back From the Dead

So I never did install the cast iron radiators downstairs, they'll be going on craigslist shortly.  My tenant is moving out and while my apt is vacant, I thought about converting my house to hot water.  Unfortunately I think the ROI will take way to long to break even, with little resale value increase on the house.  I talked to my tenant yesterday, and she stated that upstairs is almost too hot in the winter, which I find amusing because I keep the t-stat on 65 downstairs.  Again I have small vents upstairs on cast iron, and larger vents downstairs on copper/aluminum convectors. 



Bottom line, I'm going to convert all downstairs convectors to cast iron elements, and possibly remove or replace the valves (not vents) on three of the upstairs radiators because they clank like nobody's business (the rads are tilted with no avail).  I also plan on adding a third main line gorton #1.

nicholas bonham-carter

we need more pictures, and info

your system needs a bit of balancing, so let's start here with pictures.

also I suspect that setbacks are partly to blame here.--nbc