Questions about next year's project

[Kristen]

A smaller tank has a larger surface area, proportionally to the volume it contains. So more heat losses (or more thickness of insulation needed to have equivalent heat loss). Ideally you would have a spherical tank ... but other than that the biggest tank, and shape nearest to a sphere. However, a sphere doesn't help with stratification as much as a taller tank, so I suppose the take away might be:

Taller tank for best stratification
Fattest tank for water-volume (less heat loss than a skinny tank)
Fewer (big) tank(s) rather than several smaller) tanks

That said, I ahve two tanks. Main reason was that we could not get a bigger tank into the room - not because of its height, but because of the tipping height, once inside the room, because the rim of the top would hit the ceiling trying to get the tank upright.

As it turns out, in day-to-day operations, I prefer two tanks. I have Solar Hot Water heating which provide quite a bit of heat in summer, but it does a much better job (i.e. raising the temperature over 60C) of heating one 2,500L (660US Gallons) than it would a single 5,000L tank, so the heat I get in summer is much more "usable"

 

[warno]

Ok thanks for clearing that up. I'll stick with the 2 larger tanks.

 

[warno]

Now I have a question on wiring and pumps.

How is it ushally done with batch burning and storage? Do you run the pump to storage just as long as the fire is burning or a little longer? What is used to shut the pump down? If my garage is pulling it's heat from the boiler storage itself how do I run warm water back to my boiler when the garage needs more heat?

 

[warno]

Now I have a question on plumbing and pumps.

When doing batch burning and storage Do you run the pump to storage just as long as the fire is burning or a little longer? What is used to shut the pump down? If my garage is pulling it's heat from the boiler storage itself how do I run warm water back to my boiler when the garage needs more heat?

 

[maple1]

Now I have a question on wiring and pumps.

How is it ushally done with batch burning and storage? Do you run the pump to storage just as long as the fire is burning or a little longer? What is used to shut the pump down? If my garage is pulling it's heat from the boiler storage itself how do I run warm water back to my boiler when the garage needs more heat?

My boiler pump (loading unit) is wired through an aquastat with A-B switching (Honeywell, forget the model number but it's a common smaller one), and a flue temp stat, with a 3 way wire in between. On startup it's on A side to the flue temp stat. When the flue temp gets to setpoint, pump starts. If by chance the flue temp stat doesn't start the pump in time (malfunction, or maybe the flue temp doesn't build as fast as the boiler temp for some strange reason), the aquastat switches to its B side on its setpoint (think I have that at 200), which is wired directly to the pump, and the pump starts. Shutdown is the reverse - flue temp drops below flue stat setpoint & pump stops.

I'm not sure on your other question since I'm not sure of this boiler storage setup - but if you charge the boiler storage at the same time your charging your other storage, the garage would pull from it the same as the house would pull from its storage.

 

[warno]

By "boiler storage" I mean the water in the boiler itself is what the garage pulls from. There's 120 gallons in the boiler. The garage draws the heat down pretty quick when it's cold out due to lack of insulation which I plan to fix. I'll need to push hot water back from the storage tanks to the boiler for the garage. Is there any way to do that with only 2 lines in the ground. Is there a reversing pump available on the market? Or could I plumb a pump running one way then another pump running the other way on the same line and wire them so only one can run at any given time?

 

[warno]

I still need to size my water to air HX for the house but if I over size the HX will that help keep temps up in storage longer through a cold day or night or will that make the temps drop faster giving off more BTUs?

Also I plan to build a manifold that I will be running the HX and my DHW off of, should I put the HX on a zone valve or should I just let it keep circulating 24/7 with the sidearm?

 

[warno]

Any help with my recent questions? Anyone have any input?

 

[maple1]

I don't have a WAHX so no first hand experience to give, but I am thinking the thing that would drop your storage temps faster, is just your house calling for or needing more heat. So the size of the HX shouldn't matter all that much in that respect - if the house is gets satisified, the blower should turn off earlier with a bigger HX. Or run longer with a smaller one. But a bigger one would have more horsepower for recovering house temps if needed (like coming back from a setback, or from being away), and should also get more heat out of lower water temps.

On running the water all the time - I think it gets done both ways. I think OWB guys just run the water 24/7 for both WAHX & sidearm. But it could get hotter in the house than you want, in milder temps, from convection flow if it does pump all the time - depending on how well your ducts convect heat. So zone valve might be the way to go.

 

[warno]

I've been trying to figure out my plumbing on this project and I came up with this.



Would it work like this or would another way be better? Please any input would be great.

Also would I need a heat dump zone if I start doing batch burns? I'm assuming, yes. If so what is the best way to accommodate that?

 

[warno]

Could anyone help me with my drawing above? I feel an early spring coming this year, for some reason, and I want to start getting things in order early on, if possible.