Hey all,
I have a Trinity Ti-150 condensing boiler. I've lived in the house for four years and would like to make some improvements to the system. Current it does a fine job of heating the house, perhaps a little slow, maybe 90-120 minutes to heat the entire house when recovering from a setback. It seems like it could be more efficient ($3k for propane last year, minimal setbacks because we were here all the time, thermostats set at 60-62F). Also the system is very noisy. There is expansion noise (mild clicking and loud snapping) when a loop starts and big water hammer on half the loops when shutting off.
I noticed that the outdoor reset was not hooked up which makes the boiler operate in "standard mode" meaning it goes all out until it gets to the set temperature (currently 190F). I can't find an efficiency curve for this particular boiler but I assume it something like this:
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But that is for natural gas and probably low elevation. I'm on propane at 8,500 feet, which I think means it would be lower, perhaps 120F (educated guess, can't find any good info on it) instead of 135F for that "Dew Point." With this boiler I can change how aggressive the rest curve is and set the max output temp. Default curve has a revised max output temp of 141F when it is 40F outdoors, and at 0F outdoors it will use the boiler max temp. I can post a table if that helps. Anyways - are these lower temps even worth chasing? I think I'd have to give up doing setbacks...and maybe change out a bunch of radiators. I'll probably just give a try and see how it performs.
Install issues; there are two Grundfos UPS 26-99FC 1/6HP pumps, one pumping away from the boiler towards an expansion tank (I hear this is a no no as it causes air issues) and the zone valves. The other one pumps towards the boiler. There is a "closely spaced tee" set with a valve in the middle but it is right off the boiler, which doesn't match any diagram I've seen. No instructions were provided with the system so maybe that valve on the Tees was supposed to be closed anyways. I haven't looked in to pump sizing yet so I have no idea if those are over sized or what setting (hi med low) I should be using. So one thought here is get one or more fancy new variable speed pumps and relocate them so the expansion tank is before.
Lastly one of my loops might be too long...76.5 LF of radiators. Using the cheapest one I see on SupplyHouse (which matches visually) that is 600 BTU/ft at 180F, or about 46k BTU total. Grand total for all 5 loops is 181LF or 109k BTU.
Sorry this is very long and complicated. Like I said - I'm not sure where to start!
But that is for natural gas and probably low elevation. I'm on propane at 8,500 feet, which I think means it would be lower, perhaps 120F (educated guess, can't find any good info on it) instead of 135F for that "Dew Point." With this boiler I can change how aggressive the rest curve is and set the max output temp. Default curve has a revised max output temp of 141F when it is 40F outdoors, and at 0F outdoors it will use the boiler max temp. I can post a table if that helps. Anyways - are these lower temps even worth chasing? I think I'd have to give up doing setbacks...and maybe change out a bunch of radiators. I'll probably just give a try and see how it performs.
Install issues; there are two Grundfos UPS 26-99FC 1/6HP pumps, one pumping away from the boiler towards an expansion tank (I hear this is a no no as it causes air issues) and the zone valves. The other one pumps towards the boiler. There is a "closely spaced tee" set with a valve in the middle but it is right off the boiler, which doesn't match any diagram I've seen. No instructions were provided with the system so maybe that valve on the Tees was supposed to be closed anyways. I haven't looked in to pump sizing yet so I have no idea if those are over sized or what setting (hi med low) I should be using. So one thought here is get one or more fancy new variable speed pumps and relocate them so the expansion tank is before.
Lastly one of my loops might be too long...76.5 LF of radiators. Using the cheapest one I see on SupplyHouse (which matches visually) that is 600 BTU/ft at 180F, or about 46k BTU total. Grand total for all 5 loops is 181LF or 109k BTU.
Sorry this is very long and complicated. Like I said - I'm not sure where to start!