I'm trying to put together a list of parts. My goal is to preheat my dhw, not replace it. I've made up my mind to use factory-made collectors, and other than that the only big part is the tank. I currently have a stainless indirect producing off my boiler. 2 years old, good condition and produces a TON of hw. I'd like to preheat the incomming cold water to reduce the dino btus.
In a perfect world I'd replace the indirect with a 100 gallon dual coil, but unless I can find one of those for cheap I'm going with 2 tanks, one to preheat and one to boost to temp. Most 2 tanks setups are of two options: The first is a tank full of preheated water with coil used to exchange water from the collectors. The second is the storage part of the tank holding the fluid from the collectors, and then running the cold water through the coil to preheat. This is the design I'd favor because it would allow the most btus stored per the size of the tank, but because of where my collectors will end up (below the storage tank) I'm going to have to use a glycol solution for freeze protection, and because of the volume of heat diffusion liquid I would need a huge exansion tank.
Do the packaged solar setups take stagnant water into consideration?
In a perfect world I'd replace the indirect with a 100 gallon dual coil, but unless I can find one of those for cheap I'm going with 2 tanks, one to preheat and one to boost to temp. Most 2 tanks setups are of two options: The first is a tank full of preheated water with coil used to exchange water from the collectors. The second is the storage part of the tank holding the fluid from the collectors, and then running the cold water through the coil to preheat. This is the design I'd favor because it would allow the most btus stored per the size of the tank, but because of where my collectors will end up (below the storage tank) I'm going to have to use a glycol solution for freeze protection, and because of the volume of heat diffusion liquid I would need a huge exansion tank.
Do the packaged solar setups take stagnant water into consideration?