Open storage with dip tubes

[Grover59]

I have had questions as to how I set up my tank with dip tubes, here is a drawing, very simple, but it works.

Steve

 

[WoodNotOil]

From your drawing I see two things that would concern me. First you have the boilers and hx in series (which I know from exprience doesn't work well) and second you have no way of heating the open loop unless storage is up to temp and no way of heating the baseboards from storage. You should look into using a P/S piping setup instead of series and having all heat loads on the closed system with the ability to heat from wood, oil, or storage. That will give you the most efficiency, flexibility, and consistant heat.

As for dip tubes in general the pumps needs to be below the water line and you have to have some way of priming the lines. Check out my website for how I did mine. Note that I will be changing from a series hookup to a P/S this summer as the series does not work well.

 

[Grover59]

From your drawing I see two things that would concern me. First you have the boilers and hx in series (which I know from exprience doesn't work well) and second you have no way of heating the open loop unless storage is up to temp and no way of heating the baseboards from storage. You should look into using a P/S piping setup instead of series and having all heat loads on the closed system with the ability to heat from wood, oil, or storage. That will give you the most efficiency, flexibility, and consistant heat.

As for dip tubes in general the pumps needs to be below the water line and you have to have some way of priming the lines. Check out my website for how I did mine. Note that I will be changing from a series hookup to a P/S this summer as the series does not work well.

I agree with some of what you are saying, and I looked at your set up and considered maybe making some changes, there is always room for improvement. However as I was in my basement pondering the whole thing, I remembered why I set it up in this fashion, I really did not want all the heat loads on one closed loop, the big reason was that I planned to get a couple flat plate solar collectors and heat my storage with that in the summer for DHW. I like to shut my oil boiler down completely in the summer, this past summer I used electricity to heat DHW. Also I like the ability to change anything at anytime without shutting the boiler loop down.
As far as the series connection, I do lose some heat on standby with the oil boiler and I agree that this is not always the best way to go, some heat up the flue, and some just in the cellar, the flue is the bad one. Total water volume for both boilers is about 12 gallons, so I am keeping this warm most of the time. The only time that I use the baseboard is when I start the wood boiler and the loop between the oil and wood boiler reaches 180*, and if I am calling for heat, most of the time I am just heating the house with the tank. One last thing, the whole idea of using the modine heater and radiant floor heat is so that I can get my tank down to lower temps and still heat the house effectively and so far this has worked. I came home the other night my storage was at 130* and the house was still warm to the desired themostat settings, I do notice that the floor heat has a hard time to reach the temp I want because I only have that one zone done in the house, a lot of the heat in that room is making it's way to the kitchen, I will hopefully have the other side of the house done before Jan.

I will say this, I am sold on the radiant floor heat, even with that thick carpet that I have in the living room, the comfort is incredible compared to the other parts of the house. If you are in the living room, and the thermostat shows a temp of 65* you feel comfortable with no drafts, you walk back into the kitchen and you quickly feel the difference. Last night I changed my thermostat in the living room to control only the floor temp. I believe this will be better, I noticed that the air temp may reach the set point and shut the floor heat down, and then the floor would get cold, once the thermostat called for heat again it took awhile for the floor to recover. I am still playing around with this.

Steve

 

[WoodNotOil]

Sorry Maine. I read your post fast and assumed you were proposing a system design and offered feedback on it. If it works for you, go with it. You may find over time though having a fully integrated system that can heat from oil, wood, or storage may serve you better. Or maybe not! Good luck with you floor. I agree it is way more comfortable.