Cast Iron Radiator Install

lsayre wrote:

Scottscoaled wrote:... It also ramps down as zones are removed from flow. ...

Not so in this case where a single zone open demands that you squeeze 1.5 GPM of flow through only a 0.485" ID pipe into 17 feet of head. For this case the variable speed Alpha circulator must ramp up to the maximum of its pump curve to meet the GPM vs. head demand, not ramp down.

But for the case where the Alpha can deliver 10 GPM or more into 6.7 feet of head, but only 7.5 GPM are needed, this is where the variable circulator will ramp down and show benefit.

So pretty much when it's -10 outside and all the radiators and the garage modine are calling for heat, the alpha will ramp down and save me electricity lol

hotblast1357 wrote:So pretty much when it's -10 outside and all the radiators and the garage modine are calling for heat, the alpha will ramp down and save me electricity lol

The Alpha will always save you money. A conventional circulator runs at about 75 Watts (give or take), and the Alpha (at max demand) probably runs at only about 45 Watts (give or take, I have not looked up its specs, but being an ECM this is a given).

And when deadheaded the Alpha will run at perhaps 8-10 Watts, whereas a conventional circulator will still be pulling around 75 Watts.

Ok so if it saves me .25-.50 cents per day, I can stand to wait a year or two before installing it.

I don't have to worry about my grundfos dead heading, for one, I don't think the TRV's close all the way, I THINK I read somewhere there is a small hole in the center to allow some flow, I could be wrong though, and I can just leave my garage zone like it is, so it will circulate through that also even if all the TRV's are closed. But I would think one of them will always be cracked open.

The way you are describing it, the the Grundfos model UPS 15-58 FC on medium speed should do the job. You can always upgrade the circulator down the road.

And as I stated earlier, I routinely deadheaded a conventional wet rotor circulator for 10 years and it caused no harm that I could discern.

Alright, I might be off by 10' of 1/2" pipe either way, as it's just a estimate, but all this is just a estimate anyway.

hotblast1357 wrote:Alright, I might be off by 10' of 1/2" pipe either way, as it's just a estimate, but all this is just a estimate anyway.

Everything is being estimated here. Variable speed circulators pose much less of a concern (to no concern) when estimates go awry. Given what I'm calculating (educated guesstimating via mathematics) I'd give it a try with your present circulator first though, since the medium speed match to the "initially" calculated needs from one zone open through 5 zones open is astoundingly spot on.

Well and what's the worst that can happen? I need to run it on 3 or 1? The TRV's should not let the radiators overheat anyways, they should shut no matter what.

hotblast1357 wrote:Well and what's the worst that can happen? I need to run it on 3 or 1? The TRV's should not let the radiators overheat anyways, they should shut no matter what.

That's about the worst that can happen.

Well for 200 dollars, I'll play with my current pump settings for a season, and make sure the wife likes the radiators first lol

I am hookiing up a radiator hot water heating system in a home in Shamokin Pa. that was built in 1890 and still has the original rads. The landlord wanted to junk em all and the boiler and then put in electric baseboard. I talked him out of that and told him I could restore the system for less than the cost to put in radiators and he said go for it.

So far all I have found is two frozen and ruptured cast iron fittings. The supply pipe is 1 1/2" and the returns go to 2 inch back to the boiler. Fairly good sized house with 10 radiators heated by hot water from an Axman Anderson steel oil fired boiler at about 125K BTU/Hr.

First I had to start replacing the broken 90"s. One two inch in the supply and one 1 1/2" in the return line. Once that was done I cut out all the cast iron above the boiler because it looked like the beginnings of a birds nest with all the switch backs and add on's over the years. I tried to bust the fittings using the two hammer method but I don't have enough lead in my bucket to hit em hard enough. I got the roofers son who is 17 and looks like he's on steroids to do that liitle bit The malable steel ones I cut the shoulders off very carefully with a metal cutting blade in my speed controlled sawzall. Not as much fun but removal is the most fun part no matter what your workin on!!

Last night at 7:30 I finished putting the piping back together at the boiler and started filling the system hoping and praying for no leaks. Had a couple at flanges but I was able to tighten up the bolts and get them to stop. Bled air from the first floor, so far so good. Raised pressure up to get to the second floor and there is a leak coming through the stairwell ceiling. Gonna have to tear that out to see what is leaking. Told the folks that I would try to fire up the boiler so they could at least get some heat out of the first floor rads but that wasn't to be.

Bled the Becket oil burner but it wouldn't fire off. I tested the ignitor transformer and had good spark there. I opened the peep site hole and tested again and saw no spray at all in the firebox. I pulled the burner gun and there was an encrusted soot ball on the end of the nozzle that looked all black and sooty. I tried cleaning it to no avail. The nozzle must be completely cruddied up and will have to replace it.

Then I heard and saw water running from the rear of the boiler. Water started skeeting out between the hot water coil external plate and the gasket. By now it was 8:15 and no place to get parts on a Saturday night. Gave the folks the bad news, shut everything off and told em I'll be back.

I'll take some photo's of the rads when I go back on Wednesday.

alright thanks rev Larry! take some pics of the piping and pumps please.

do these radiators have trvs? or just manual shut off's?

are they in series or parallel?

so here is my only room that I do not know where the best place is for radiator locations.

these BTU ratings are at 160 degree's, so they can put out more heat if need be.

the green radiator is what I would like to do, it would be the most open situation.

the yellow radiators are what I can do, but the couch and chairs are in front of them, so I don't know if thats going to effect the radiation, I know there "suppose" to be under windows, but would the green one keep the room warm?

OK, I woke up (hopefully refreshed) this morning (despite not having slept at a Holiday Inn Express) and re-assessed my calculations, and found where I had made a huge error at the 5 zones open end of the equation. I now believe that if you have a system with 5 zones, each of which has roughly 150 feet of 1/2" PEX that has an ID of 0.485", this is roughly the best that the Alpha circulator can deliver when admittedly only quickly 'eyeball' matched (as opposed to precision plotted) against the Alpha's maximum pump curve line (which quite oddly is noticeably swaybacked):

1 zone open: 150 feet of 0.485" PEX, effective ID = 0.485", 1.5 GPM into a calculated 16.9 feet of head = 15,000 BTUH
2 zones open: 300 feet of 0.485" PEX, effective ID = 0.686", 2.5 GPM into a calculated 16.1 feet of head = 21,000 BTUH
3 zones open: 450 feet of 0.485" PEX, effective ID = 0.840", 3.2 GPM into a calculated 14.3 feet of head = 32,000 BTUH
4 zones open: 600 feet of 0.485" PEX, effective ID = 0.970", 3.96 GPM into a calculated 13.9 feet of head = 39,600 BTUH
5 zones open: 750 feet of 0.485" PEX, effective ID = 1.084", 4.6 GPM into a calculated 13.4 feet of head = 46,000 BTUH

If you truly need to be able to deliver 75,000 BTUH when all zones are fully open, the Alpha (and the Einstein) is (are) totally inadequate to the task. The 1/2" PEX with its restrictive 0.485" ID is a single circulator system killer. The saving grace here may be that you really do not need to deliver 75,000 output BTUH to heat your home on the single coldest day of the year.

No no no! Lol 150' of TOTAL PEX FOR THE 5 LOOPS lol

hotblast1357 wrote:No no no! Lol 150' of TOTAL PEX FOR THE 5 LOOPS lol

That changes everything in a huge way. You are back to my original calculation of 6.64 feet of head at 7.5 GPM of flow with all 5 zones open.