New Boiler Install

vvzz

Hi All!
My grandfather was a wethead and I my favorite toys to play with were black fittings when I was little. It's only natural that as I got older I only got more fascinated and drawn to hydronic heat. In my other house I ripped out all fin-tube baseboards toyed around with near boiler piping to do a full reset for new CI rads via injection mixing.

When I bought the house no2 - a once grand single family, converted to three family and now being converted back; the first things I did was ripping out all the baseboards and three 100k BTU Burnham Revolutions. This gave me an opportunity to design the new system from scratch. This forum, Dan's books, engineering background and of course John Siegentaler's book were indispensable in that. I don't really have any questions, but I figured I would share my experience as a thank you for all the great info here.

I knew what I wanted from the beginning - constant circulation with ornate cast iron radiators(to compliment victorian decor of the house) controlled with TRV valves. Procuring the radiators is a story of its own. They are getting harder and harder to find. I think I also got quite proficient at rigging and creative moving as few of the rads I got weight around 400lbs or more(16 section 38" american radiator rococo)

Since this was a new design, I was able to match the radiators very closely to the heat loss of each room while also being able to plan for low temperatures(140 degrees) The whole building's heat loss came at around 80K BTU(no insulation and original windows which I value very much), so I went with the triangle tube 110 excellence. I have also left stub outs for few infloor radiant loops. That will be completed as the kitchen and bathrooms are renovated(if you look at the boiler piping you will see a pump isolation flange, which I realized later is pointless since it has it has to go after TRV mixing valve, so thats that...)

For the system layout I chose a basic primary/secondary via a hydronic separator. I really feel like it's a very elegant engineering solution. The distribution is done via a manifold and 1/2 uponor MLC to each radiator.

So far the system has 3 radiators connected(few more are going in in the next few days) And the comfort level in the first floor rooms(which has 2 big rads) is really superb. Since it's still a shoulder season and I don't even have all the rads connected, I enabled call blocking on the boiler to avoid short cycling. I'm getting about 12 minute burn times every 30 mins and the boiler is modulating all the way down(45-50 outside). I'm pretty happy with that. I calculate that once the boiler is fully loaded, I should get near continuous burn times most of the time.

vicbrick

vvzz, thanks for the sharing your install. Really like those beautiful rads!

I also did a similar install this summer (similar house, same boiler, same love of wavy glass windows .......and continue to learn.

So, if you could help me understand why you selected constant circulation for your heating upgrade? What value does constantly circulating the water 24/7 offer versus using the CH demand call to turn on/off the system pump?....is it largely for the radiant infloor that will be done later? (I have an all CI rad system)

Thanks !

Paul Pollets

https://heatinghelp.com/systems-help-center/buffer-tanks/

Paul Pollets

Here's Joe Friedrich's article. He was the man who popularized the "continuous circulation" hydronic design in N. America.

http://hydronicsmfg.com/Contractor article 1996-06.pdf

vvzz

I grew up with constant circulation systems(via district heat) in Russia. That heat worked very well and always warm radiators kept the apartment very comfortable.

The house looses heat continuously, so it also makes sense to replenish that heat all the time to achieve maximum comfort. And with a modulating boiler it's almost silly not to.

I also like the idea of each room being individually zoned via a thermostatic valve. No complicated zone panels or micro zones and yet I can keep my bedroom at 60 degrees for sleeping while still have comfortable temperature in other rooms.

I think(and many posts here seem to agree) that cast iron radiators works just as well for constant circulation as radiant floors.

I also have a theory(which I haven't really seen mentioned anywhere) that constant circulation does a great job redistributing heat around the house even if the boiler is off. Some radiators might get hotter faster than others and the hotter return water from them will mix with other returns and 'help' the other radiators. Just a theory though - I haven't done any calculations to support that.

Paul Pollets

Another important Friedrich paper: http://www.comfortableheat.net/pdfs/continuous.pdf

Gordy

vvzz said:

I also have a theory(which I haven't really seen mentioned anywhere) that constant circulation does a great job redistributing heat around the house even if the boiler is off. Some radiators might get hotter faster than others and the hotter return water from them will mix with other returns and 'help' the other radiators. Just a theory though - I haven't done any calculations to support that.

It's a good theory so don't lose sight of it.

Btu redistribution with constant circulation is a great way to plain out the highs, and lows. In a total system.

It can also work against you in certain instances, but not often.
Those situations would be an under radiated space that might benefit holding that hot emitter a little longer.

vicbrick

Hey, thanks for all the information/links. Greatly appreciated!
Think I have a much better understanding of why one would choose constant circulation....always a lot of parameters to balance with hydronic heating...keeps it interesting!

SWEI

The greater the thermal mass, the more important constant circulation becomes. Remember that system water content, metal pipes and radiators, and building thermal mass (concrete, brick, and stone) ALL constitute thermal mass.

vvzz

I've had the system running for a couple months now and one thing that really continues to impress me is how well the hydraulic separator removes air(pumping away probably helps too). I have previously dealt with typical systems with a basic scoop and those air bubbles keep making noises for months.

njtommy

Did you get all your rads installed yet? Looks good

vvzz

No, I still have to do 2 second floor bedrooms and the hallway. I was originally gonna put corto-style 23" radiators on the second floor(which I got), but I was able to get a hold of beautiful American Radiator rococo ones, to match the first floor(and also in somewhat rare 23" height) Unfortunately the guy I'm getting them from is doing a reno and my rads are blocked off by a dumpster.

Meanwhile, I connected baseboards on the third floor(to be eventually replaced with either more cast iron or radiant) to the manifold to give the boiler a little more to chew on. That worked pretty well and I got even longer burn times.

Gordy

vvzz said:

I've had the system running for a couple months now and one thing that really continues to impress me is how well the hydraulic separator removes air(pumping away probably helps too). I have previously dealt with typical systems with a basic scoop and those air bubbles keep making noises for months.

Pumping away is a lot of it.