Storage control

[djblech]

I am thinking of installing storage before next year, and I am just figuring out the hook-ups. I am trying to understand how I would control whether my heat (water) goes to the house if it is calling or to storage. I am wondering if there is a way using a zone control valve or if I need a controller of some sort. One problem I see is that I need an aquastat to shut off my furnace pump so I don't pull hot stored water back to a cooling furnace. Currently I run a circ pump constantly between the furnace and the hx.
Thanks for any feedback

 

[sparke]

If you can post a drawing of your system it would help. Show the location of both boilers, pumps, valves, etc...

 

[timberr]

djblech,

In my system my boiler only heats storage, when there is a call for heat the hot water comes from storage. I usually do 2 burns per day and everything works fine. When we have temps at 0 or below then I need to keep the boiler running all night. The plumbing is easier that way. I have a Circ on the boiler to pump to storage and a circ on storage to pump to secondary loop.

Good luck

 

[sdrobertson]

I have 4 tanks - all the tanks are hooked together with manifolds. The tops run to one manifold and the bottoms run to another. I have the boiler hooked into the manifolds and also the house zone is hooked into the manifolds. When the boiler is running I have a motorized two way valve that will only allow water that has reached 185 degrees to leave the boiler and go to the manifold. The house zone has its own circ and when I'm calling for heat this circ is on and draws from the manifold which is either supplied with storage water or boiler water but it doesn't care which. The bottom manifold also has a line to the boiler and a line from the house zone. This also doesn't care where it puts the water, into the bottom of storage or into the bottom of the boiler.

 

[Nofossil]

I am thinking of installing storage before next year, and I am just figuring out the hook-ups. I am trying to understand how I would control whether my heat (water) goes to the house if it is calling or to storage. I am wondering if there is a way using a zone control valve or if I need a controller of some sort. One problem I see is that I need an aquastat to shut off my furnace pump so I don't pull hot stored water back to a cooling furnace. Currently I run a circ pump constantly between the furnace and the hx.
Thanks for any feedback

Both the 'primary / secondary' and 'simplest pressurized storage' stickies at the top of the page discuss control strategies. Sounds like you're plumbed very much like the 'simplest pressurized storage' approach.

 

[djblech]

I think the "simplest storage system" is kind of like mine. (Because I see things linear, its hard for me to compare it to mine.) Basicly, I had a gas boiler with a manifold that has 3 baseboard zones and 2 radiant zones and a hot water maker zone. I extended the gas boiler manifold to loop in a hx. I use the original gas boiler pumps to circulate through hx and house. I then have a loop from the boiler to the hx that circulates all the time. My gas boiler is turned down to 140* and has not kicked in since I started the wood boiler in Dec. It seems that if I put the storage in my basement, and just ran to storage instead of the hx this might be the simplest. Timberr said his system is hooked up this way. I wonder if my boiler will keep up.

 

[2.beans]

I am thinking of installing storage before next year, and I am just figuring out the hook-ups. I am trying to understand how I would control whether my heat (water) goes to the house if it is calling or to storage. I am wondering if there is a way using a zone control valve or if I need a controller of some sort. One problem I see is that I need an aquastat to shut off my furnace pump so I don't pull hot stored water back to a cooling furnace. Currently I run a circ pump constantly between the furnace and the hx.
Thanks for any feedback

i use a three way zone valve and an aquastat to isolate my boiler from my tanks. the valve only opens when supply water is above 170*

 

[chuck172]

Could you go into more detail 2.beans, Are you saying that the zones never see water temps above 170?

 

[2.beans]

the zones get what the tank gets up to in temp. right now i have the tanks set at 175* with a differential of 20, so when the tank temp drops to 155* it allows the draft to open on the boiler to heat the tanks up.i have a seperate aquastat for that. when the boiler starts back up the three way zone valve wont let supply water into the tank until its over 170* this helps with my stratification by letting in only hot water to the top of the tank. it doesnt slowly mix the water up. also the boiler doesnt cycle during the burn. now that its getting warmer i have been messing around with the settings to get down to one fire a day.

 

[chuck172]

the zones get what the tank gets up to in temp"
By that I take it that you only feed the load through the tanks. You don't ever just by-pass the tanks and heat the zones directly. Correct?

 

[2.beans]

i can do that as well but for the most part i dont need to. i have it set up so if i want to bypass the tanks and go straight to the zones all i have to do is flip a switch. once the zones stop calling the supply switches back over to charging the tanks. then when the tanks are at temp the house will run off them. once the tanks are depleted it starts all over again. i only need this when it stays below zero.