Please help me design my boiler setup

[juddspaintballs]

(broken image removed)

A very crude drawing. Let me know what you think. I'll add kitchen heat later on if I feel like a super-warm house isn't enough. Right now I'm keeping the house at 67 degrees (COLD!) on my old oil burner and still getting killed on buying oil.

 

[Gooserider]

I assume the little yellow deals are valves, and the green ones are pumps, correct?

Looks pretty decent, except, as I mentioned I would look into doing a "sidearm" HX on the water heater, rather than a flat plate. If you do a sidearm, you will automatically charge the DHW tank via thermosyphoning, if not you will need a second pump on the DHW side of the HX. Either way you will definitely want a mixing valve on the DHW line to the house.

For a really neat setup, check out NoFo's website (in his sig on any of his posts) and look at how he does his two stage hot water mixing - a bit extra on the plumbing, but guarantees just about infinite hot water...

If you do go with a flat plate, it is probably worth looking up the thread I referenced in the Tidbits sticky on the care and feeding of FP's especially including the Webstone valves that HR suggested to allow easily isolating and flushing the HX.

Gooserider

 

[juddspaintballs]

I'll check out sidearms and NoFo's plumbing later on today. I'll also try drawing up the other kind of setup later today too, though I'm favoring this setup so far. The Taco 007's are fairly inexpensive at $60/each, which is about the price of a zone valve.

 

[juddspaintballs]

Let's try this setup. The green circle R is a relief valve, one zone valve on the A/W heat exchanger, ball valves on everything else. I am favoring this setup now. Water always flowing through the DHW, garage heat will only be turned on when I'm out there, so therefore, no zone valve on it. Some fancy plumbing at the water heater, allowing me to either bypass the heater, or use it as a storage tank, or turn off the sidearm exchanger and use the water heater as normal. Mixing valve after the water heater.

(broken image removed)

 

[Gooserider]

The sidearm plumbing needs a bit of attention to make it do right...

Essentially a sidearm needs to have the DHW side plumbed alongside the DHW tank and tied to it at the top and bottom. The boiler side should go in the top and out the bottom. This way you get thermosyphon flow as the cooler water in the tank flows into the sidearm, gets heated and flows into the top of the tank, pushing / pulling more cooler water in at the bottom, etc. Basic gravity flow, but it MUST be set up so that gravity can work...

Easiest way to do this on most tanks is to pull the drain valve and put in a tee - the straight section goes to the drain, and the branch goes up to the sidearm. On the top side, you can either tee into the tanks hot water out line, or do the same tee setup at the T&P valve connection - the branch goes to the sidearm, and the T&P valve goes into the straight.

Some like to put the makeup water into the bottom of the sidearm, others prefer to leave it going in the cold water dip tube per stock...

Once the sidearm has been verified leak free, it and the associated plumbing should be heavily insulated.

Gooserider

 

[juddspaintballs]

Changed the DHW setup a little bit. Still have it plumbed in case I want to bypass the water heater completely.
(broken image removed)

Learned a little bit about sidearm exchangers vs. flat plate. If I get a large tube or sidearm exchanger, convection will take care of the flow through it as it's plumbed. That's what I'll go with. Unless you see any problems with this setup, I think this will be the route I'll take.

Here's the sidearm I'm thinking about
(broken link removed to http://www.outdoorfurnacesupply.com/side-heat-exchanger-p-89.html)

How good is the Taco electronic ball valve for a zone valve?

My next step will be learning wiring for this sucker

 

[Gooserider]

Changed the DHW setup a little bit. Still have it plumbed in case I want to bypass the water heater completely.

Not bad, as long as you keep the distance between the top of the tank and the sidearm connection really short. I just did a quick minimal layout of a sidearm in QCAD, this is a slightly better way to configure it, as it eliminates the downward loop coming out of the sidearm....

Learned a little bit about sidearm exchangers vs. flat plate. If I get a large tube or sidearm exchanger, convection will take care of the flow through it as it's plumbed. That's what I'll go with. Unless you see any problems with this setup, I think this will be the route I'll take.

Exactly - this is why I like sidearms better - no moving parts, no electric power needed, less likely to have problems w/ mineral buildup, etc...

Here's the sidearm I'm thinking about
(broken link removed to http://www.outdoorfurnacesupply.com/side-heat-exchanger-p-89.html)

Looks like a nice unit.

How good is the Taco electronic ball valve for a zone valve?

They are supposed to be pretty good - there were a few problems with the actuators on the early units, but those have supposedly been ironed out now. One of the things I like about the EBV is that it doesn't draw any power except when it's changing state, unlike the traditional ZV's that always drew a small amount of power when active.

My next step will be learning wiring for this sucker

Shouldn't be any harder than doing the plumbing diagram... Again you'll have a fair number of choices, but if you keep it simple things shouldn't be very difficult.

Gooserider