I think I’ve pigeonholed myself in this aspect, Garn And flat plate are in the barn 75ft from house, primary odr mix valve is between the Garn and flat plate. The thought is to limit the exposure of high temp water in the insulated pex underground. The Tekmar controller on a dwh call will temporarily raise the temp beyond the odr mix temp to satisfy the demand and resume mix temp after, it also looks at the oil boiler temp, if wood won’t cut it after a set time it the ob satisfies and will resume to wood after.
This all works but there are a few caveats, 1. The default dwh oil temp is the max limit for the oil boiler, which is recommend to be 10 deg above the max odr temp. So if your max odr temp is 145, the max ob temp is 155, this is based upon not short cycling the oil boiler, makes sense from that standpoint but kind of overkill to satisfy a indirect tank with a 127 setting with a 3 deg cut in differential.
2. That dwh temp really disrupts a odr curve for the rest of the system on a regular basis.
I realize this is splitting hairs but why take 155 deg storage water that could go along way to house heating at much lower temps to heat a indirect tank with its own losses to eventually supply a 103 deg shower.
So I’m monitoring the time with a old analog clock that the dwh circ currently runs over a 2 week period.
I’m not changing the odr mix temp setup to bring storage water temp to the house and pull dwh from there, I’m thinking of taking dwh out of the wood equation all together with a wall hung tankless gas unit. I already have gas in the house, and the analog clock will give a indication as to how much farther storage could go to house heating. What am I overlooking?
This all works but there are a few caveats, 1. The default dwh oil temp is the max limit for the oil boiler, which is recommend to be 10 deg above the max odr temp. So if your max odr temp is 145, the max ob temp is 155, this is based upon not short cycling the oil boiler, makes sense from that standpoint but kind of overkill to satisfy a indirect tank with a 127 setting with a 3 deg cut in differential.
2. That dwh temp really disrupts a odr curve for the rest of the system on a regular basis.
I realize this is splitting hairs but why take 155 deg storage water that could go along way to house heating at much lower temps to heat a indirect tank with its own losses to eventually supply a 103 deg shower.
So I’m monitoring the time with a old analog clock that the dwh circ currently runs over a 2 week period.
I’m not changing the odr mix temp setup to bring storage water temp to the house and pull dwh from there, I’m thinking of taking dwh out of the wood equation all together with a wall hung tankless gas unit. I already have gas in the house, and the analog clock will give a indication as to how much farther storage could go to house heating. What am I overlooking?
