Radiant install questions

DigitalBob

I am finishing up a radiant install.  Story and a half house, 41017 zip code.  First floor is staple up.  This is complete.  It has five loops connected off one manifold fed by 1" copper.

I am in the process of doing second floor.  It will be two loops sandwiched between subfloor and hardwood fed off the same manifold. 

First floor requires 26,250 BTUH.  Second floor is roughly 5,000 BTUH giving me a total demand under 32,000 BTUH.  So far, so good.

My question is boiler choice.  I previously had tube and fin radiators with a 30 year old 100,000 BTU boiler.  Needless to say, this is less than optimal.

For boiler replacement I have looked at two:



Peerless PF50 - modulates from 15k to 130k BTUH

Triangle Tube Prestige Solo 60 - modulates from 16k to 60k



Does anyone have any preference one way or the other?  It seems strange switching from a 100,000 BTUH boiler to one so small (and even then only needing just over half of it's capacity).  Have I missed anything? 

Thanks-

Patrick

CMadatMe

Before Boiler Choice

How do you plan on controlling the radiant? What are you doing for domestic hot water? Curious before I give my boiler choice.

EricAune

Comment on the boilers

Are the water temps needed for the two zones within 5-10 degrees of each other?  If so then my choice would be the TT with primary secondary piping utilizing a Taco variable speed delta t circulator as your secondary pump.  This boiler, IMOP, has a superior heat exchanger than the Peerless that will also alleviate the need for a low loss header or larger diameter boiler loop piping and circ.



This set-up is rather simple and most often the simple is what works best.

NRT_Rob

I'd question primary/secondary

on systems this small.



the first and most important question is what boiler is best serviced locally?



no boiler is worth much if you can't get parts or anyone to work on it. all else being equal I agree the solo 60 is a great boiler.



with a 32kBTU load, it should be possible to run this system without secondary piping at all, and either of those boilers should be fine as long as no zone runs with less than 1 GPM.

DigitalBob

Hot water

I have a Paoloma tankless unit (199,000 btu) installed.  I went with something so large as to have sufficient hot water for two showers as well as a jacuzzi tub.   As far as control...good question.  There will only be two thermostats.  Ideas? 

DigitalBob

Room temp

The entire 2nd floor (secondary loop) is the master bedroom so it will tend to be on the very cool side...low to mid 50's is my preferred sleeping temp.

CMadatMe

My boiler of Choice

would be a Viessmann Vitodens 200 with a modulating 3-way mixing valve. I would add a Vitotrol 300 for indoor feedback  and be on my merry way.