Thoughts on DHW, Sidearm vs. Flat Plate, Controls, etc.

[Clarkbug]

Hi All.

So Im still waiting on my boiler guy to come and actually hook up some pipes. While this is sad, it did give me an opportunity to try and simplify things some, I think.

I was intending to plumb up the two zones in my house now, but leave some on the manifold capped for future use. One of these I had hoped to hook up to serve as a zone for DHW. I currently have an electric tank type heater, and was thinking about either a sidarm or a flat plate with dual circs. The problem was going to be that I didnt want to heat the DHW tank with oil if for some reason the wood boiler was out, and there was a call for heat. My first thought was a couple of different sets of relays of some sort, but I had another thought this weekend.

There are pics of my intended piping diagram around here in a different thread, or you can reference the PT1 diagram from Tarm/BioHeat. My thought was to instead take an additional branch off of the "load" feeds out to the house, but directly adjacent to my storage tanks. This separate supply/return would go to the sidearm or the flat plate, and have its own circulator. I would put an aquastat on the tanks (or use the one thats going to control the wood/oil changeover), and another on the DHW tank itself. When there is a demand for heat from the DHW tank, and the aquastat on the boiler storage tanks says its hot enough, then it would run the pump until the DHW tank is satisfied. I figure this way I would only need a single switching relay to operate this zone, and it would also let me pull more heat out of the storage tanks since I have baseboard and need hotter water to keep the house comfy.

Any thoughts on this setup? Any reason not to proceed this way? I think I might have to incorporate an additional check valve in my system somewhere, but thats not a big deal at this stage of the game.

Also, is the additional expense of a flat plate and circ worth it, or will the sidearm perform OK when hooked up in a zone configuration? Can a switching relay control both circs simultaneously without a problem? (Since with a flat plate I would need to pump the boiler water and domestic water)

Thanks in advance!

 

[taxidermist]

Hi All.

So Im still waiting on my boiler guy to come and actually hook up some pipes. While this is sad, it did give me an opportunity to try and simplify things some, I think.

I was intending to plumb up the two zones in my house now, but leave some on the manifold capped for future use. One of these I had hoped to hook up to serve as a zone for DHW. I currently have an electric tank type heater, and was thinking about either a sidarm or a flat plate with dual circs. The problem was going to be that I didnt want to heat the DHW tank with oil if for some reason the wood boiler was out, and there was a call for heat. My first thought was a couple of different sets of relays of some sort, but I had another thought this weekend.

There are pics of my intended piping diagram around here in a different thread, or you can reference the PT1 diagram from Tarm/BioHeat. My thought was to instead take an additional branch off of the "load" feeds out to the house, but directly adjacent to my storage tanks. This separate supply/return would go to the sidearm or the flat plate, and have its own circulator. I would put an aquastat on the tanks (or use the one thats going to control the wood/oil changeover), and another on the DHW tank itself. When there is a demand for heat from the DHW tank, and the aquastat on the boiler storage tanks says its hot enough, then it would run the pump until the DHW tank is satisfied. I figure this way I would only need a single switching relay to operate this zone, and it would also let me pull more heat out of the storage tanks since I have baseboard and need hotter water to keep the house comfy.

Any thoughts on this setup? Any reason not to proceed this way? I think I might have to incorporate an additional check valve in my system somewhere, but thats not a big deal at this stage of the game.

Also, is the additional expense of a flat plate and circ worth it, or will the sidearm perform OK when hooked up in a zone configuration? Can a switching relay control both circs simultaneously without a problem? (Since with a flat plate I would need to pump the boiler water and domestic water)

Thanks in advance!

You should not have to pump your DW when you open your hot water tap you could have a flow swithc turn on a pump to run boiler water thru one side and your well/city dw pressure will run it thru the other. With a flat plate sized right you can have a on demand system. This is what I am doing. I have to wire in the pump and switch when I get home from deer camp.

Rob

 

[Clarkbug]

Thanks Taxidermist.

I think that I want to heat my tank instead of trying to do the on-demand thing just so I have another zone to dump some heat into. That way if for some reason my boiler goes out or there isnt enough heat in my tanks, the electric elements will kick back on and keep things a minimum temp.

Ill look into the on-demand idea, its not one I have considered before, but Im not sure if I like the flow switch thing, just since I dont know how reliable they are.