See Part 6 for links to Parts 1-6.
I'm lamenting the lack of any real winter this season, cold that is. With the Deep Portage improvements, including the added 4000 gal of pressurized storage, correction of the problem with the return water protection valve for the Wood Gun, and more accurate gpm flow calculations through use of measuring differential pressure on the circulators, the only other thing that's needed is a few really cold days and nights to again put these two fine boilers through some high output paces. That cold weather still is not in the forecast, and may not happen this season.
Observational and anecdotal perspectives:
1) The 4000 gal new storage (plus the 3200 gal of the Garn) has enhanced the combined boiler system performance considerably. The ability to have 7200 gal of 160F+ water has really smoothed out supply temperature and simplified operation of the heating system. With nearly 2 million stored btu's, good for 4 or more hours of heat from storage only, both day but especially night operations have become effortless.
2) It is now all but impossible to overload either boiler to cause the Garn temp to get too high or cause the Wood Gun to idle. Based on general winter cold conditions, the chief operator sets a target temperature for mid-tank of the 4000 gal storage tank, and staff just loads either one, the other, or both boilers to achieve that target during the day and especially for stating the night. Load 100 or so lbs of wood, which is pretty much a full load for either boiler, and walk away.
3) Staff preference and hot water temperature requirements have shifted to more use of the Wood Gun over the Garn, primarily because the Wood Gun puts out 170-185F water consistently when fired without needing to preheat any of the 7200 gal of storage. The 4000 gal storage tank is supplied directly by the Wood Gun and is plumbed as a hydraulic separator, and if storage is down to 130F, for example, firing the Wood Gun delivers that extra hot water to the top of the tank, which flows through to top of tank supply to system, and the heating system has all the hot water it needs. Extra boiler output then can gradually heat the entire tank without shorting or delay in supplying the heating system demand. Also, I don't think the Wood Gun ever has gone into idle this season, which was an unpleasant occurrence (to be avoided) last year.
4) Garn use has been heaviest in two situations. First, in fall and early winter (and probably also this coming spring) when higher temperature water has not been needed. Second, to quickly boost the temperature of the entire 7200 gal of storage. At temperatures seen so far this season, the Wood Gun output normally is sufficient to meet system demand, but at higher demand periods it cannot also build-up reserve storage temperature very quickly. This is where the extra output offered by the Garn is very helpful, as both boilers together have an output to system in the range of 1 million btuH, or around 500,000 btuH for each.
5) Perhaps best of all from an economic perspective, use of LP for space heating from the now backup LP boiler system is 0, and use of LP for DHW has been greatly reduced. No more big payments to the "oil man." Plus, use of local wood has supplied jobs for local loggers and firewood cutters, supported local families, and aided the local economy -- all through use of a local, sustainable, fuel wood source of energy. This is a win - win operation for jobs and the environment.
I'm lamenting the lack of any real winter this season, cold that is. With the Deep Portage improvements, including the added 4000 gal of pressurized storage, correction of the problem with the return water protection valve for the Wood Gun, and more accurate gpm flow calculations through use of measuring differential pressure on the circulators, the only other thing that's needed is a few really cold days and nights to again put these two fine boilers through some high output paces. That cold weather still is not in the forecast, and may not happen this season.
Observational and anecdotal perspectives:
1) The 4000 gal new storage (plus the 3200 gal of the Garn) has enhanced the combined boiler system performance considerably. The ability to have 7200 gal of 160F+ water has really smoothed out supply temperature and simplified operation of the heating system. With nearly 2 million stored btu's, good for 4 or more hours of heat from storage only, both day but especially night operations have become effortless.
2) It is now all but impossible to overload either boiler to cause the Garn temp to get too high or cause the Wood Gun to idle. Based on general winter cold conditions, the chief operator sets a target temperature for mid-tank of the 4000 gal storage tank, and staff just loads either one, the other, or both boilers to achieve that target during the day and especially for stating the night. Load 100 or so lbs of wood, which is pretty much a full load for either boiler, and walk away.
3) Staff preference and hot water temperature requirements have shifted to more use of the Wood Gun over the Garn, primarily because the Wood Gun puts out 170-185F water consistently when fired without needing to preheat any of the 7200 gal of storage. The 4000 gal storage tank is supplied directly by the Wood Gun and is plumbed as a hydraulic separator, and if storage is down to 130F, for example, firing the Wood Gun delivers that extra hot water to the top of the tank, which flows through to top of tank supply to system, and the heating system has all the hot water it needs. Extra boiler output then can gradually heat the entire tank without shorting or delay in supplying the heating system demand. Also, I don't think the Wood Gun ever has gone into idle this season, which was an unpleasant occurrence (to be avoided) last year.
4) Garn use has been heaviest in two situations. First, in fall and early winter (and probably also this coming spring) when higher temperature water has not been needed. Second, to quickly boost the temperature of the entire 7200 gal of storage. At temperatures seen so far this season, the Wood Gun output normally is sufficient to meet system demand, but at higher demand periods it cannot also build-up reserve storage temperature very quickly. This is where the extra output offered by the Garn is very helpful, as both boilers together have an output to system in the range of 1 million btuH, or around 500,000 btuH for each.
5) Perhaps best of all from an economic perspective, use of LP for space heating from the now backup LP boiler system is 0, and use of LP for DHW has been greatly reduced. No more big payments to the "oil man." Plus, use of local wood has supplied jobs for local loggers and firewood cutters, supported local families, and aided the local economy -- all through use of a local, sustainable, fuel wood source of energy. This is a win - win operation for jobs and the environment.