Edit: added second drawing
Good evening guys,
I was wondering if anyone would be willing to give me some guidance on this. This is the job I posted about before, where we lost the bid and they gave the job to the low bidder. They royally messed it up and they're struggling to keep the heat on in the building - an old folks nursing home. I would like to propose a complete solution, not a patch job. Including new boilers, piping, venting, and controls. This is a large customer, 30+ properties and we have their maintenance contract. If they don't approve a complete fix I am going to walk away. But I at least would like to provide them a full solution. I attached a picture of what I had in my head.
I have no idea if this would be the best way to do it. There are two Weil McLain Slimfit 550 boilers. There is a water source loop that stays at 70 degrees during the winter. And there is a 100% outdoor make-up air coil also in the boiler room that needs hotter supply water as it gets colder outside to maintain a 68 degree supply air temp to the building. The pumps, mixing valve, and diverting valve are there already piped to the loop / coil how I drew them. (sorry for the messy drawing, I'm not good with hydrosketch yet).
Am I on the right track? Or is this not even close? I know the boiler piping isn't drawing 100% accurately and if I am not mistaken the two secondary loops with the 3-way valves would need a check valve on them.
Never stop learning.