I know that is a good idea to make hot water a priority in a normal boiler system but, does it make sense to make and indirect hot water tank a priority zone in a wood boiler system being that there is a lage amount of storage?
Dean
Dean
Eric Johnson said:If you never want to hear the words: "Honey, there's no hot water," then you will make DHW a priority in any system.
Rick Stanley said:I'm gonna have underground pex coming through the cellar floor from a Garn, going through a flatplate hx, then back to the Garn. The other side of the hx will be
pressurized and piped to the heat zones.
I want to add an indirect water heater and circulator. To make dhw a priority, it sounds like I should tee into the supply pipe coming from the Garn BEFORE it reaches the hx.
Does that sound right?
Thanks
Rick Stanley said:I'm gonna have underground pex coming through the cellar floor from a Garn, going through a flatplate hx, then back to the Garn. The other side of the hx will be
pressurized and piped to the heat zones.
I want to add an indirect water heater and circulator. To make dhw a priority, it sounds like I should tee into the supply pipe coming from the Garn BEFORE it reaches the hx.
Does that sound right?
Thanks
Eric Johnson said:If you never want to hear the words: "Honey, there's no hot water," then you will make DHW a priority in any system.
Jim K in PA said:Rick Stanley said:I'm gonna have underground pex coming through the cellar floor from a Garn, going through a flatplate hx, then back to the Garn. The other side of the hx will be
pressurized and piped to the heat zones.
I want to add an indirect water heater and circulator. To make dhw a priority, it sounds like I should tee into the supply pipe coming from the Garn BEFORE it reaches the hx.
Does that sound right?
Thanks
Rick - that is not necessary, and not what DHW priority means. HW priority on a zoned system means that the DHW demand will be satisfied before any other demand is supplied. This can be accomplished a number of ways. I am using a TACO ZVC-406 with priority. It is a zone valve controller with the 6th zone set up for (optional) priority. The valve (or pumps) for zones 1-5 will not energize if zone 6 is energized. Once Zone 6 is satisfied, then the other zones will energize (on a heat call, of course). The TACO SRCs will do the same thing with their priority on the last relay.
Rick Stanley said:Jim K in PA said:Rick Stanley said:I'm gonna have underground pex coming through the cellar floor from a Garn, going through a flatplate hx, then back to the Garn. The other side of the hx will be
pressurized and piped to the heat zones.
I want to add an indirect water heater and circulator. To make dhw a priority, it sounds like I should tee into the supply pipe coming from the Garn BEFORE it reaches the hx.
Does that sound right?
Thanks
Rick - that is not necessary, and not what DHW priority means. HW priority on a zoned system means that the DHW demand will be satisfied before any other demand is supplied. This can be accomplished a number of ways. I am using a TACO ZVC-406 with priority. It is a zone valve controller with the 6th zone set up for (optional) priority. The valve (or pumps) for zones 1-5 will not energize if zone 6 is energized. Once Zone 6 is satisfied, then the other zones will energize (on a heat call, of course). The TACO SRCs will do the same thing with their priority on the last relay.
What do you guys think of this?
I already have an insulated 40 gallon dhw tank that is piped to a coil in my oil boiler with a circulator/aquastat set-up. It works great. Provides plenty of hw for two families. Could it be as simple as adding a flat plate hx for dhw and have the existing circulator push water through that, when I'm burning wood, and through the existing coil when burning oil? What would be possible drawbacks to that? Maybe couldn't keep up with heavy demands as good as the oil burner does? I don't know. Any thought?
Thanks!! ps- possibly, maybe, the priority thing is already handled with that little dhw circulator being wired with priorty? How could I check?
Rick Stanley said:What do you guys think of this?
I already have an insulated 40 gallon dhw tank that is piped to a coil in my oil boiler with a circulator/aquastat set-up. It works great. Provides plenty of hw for two families. Could it be as simple as adding a flat plate hx for dhw and have the existing circulator push water through that, when I'm burning wood, and through the existing coil when burning oil? What would be possible drawbacks to that? Maybe couldn't keep up with heavy demands as good as the oil burner does? I don't know. Any thought?
Thanks!! ps- possibly, maybe, the priority thing is already handled with that little dhw circulator being wired with priorty? How could I check?
Rick Stanley said:Now, in considering other options, I looked at what I already have in place and that is this: There's an oil boiler with a dhw coil in it. Sitting 2 ft away is a 40 gallon tank, piped into the coil, with a circulator in the loop. I look at that and think that there must be a simple way to use a second smaller dhw flat plate hx to replace to coil in the boiler and then I could let the oil boiler go cold when I'm burning wood and make use of the tank and circulator that's already in place.
Does any of this make sense?
Jim K in PA said:Rick Stanley said:Now, in considering other options, I looked at what I already have in place and that is this: There's an oil boiler with a dhw coil in it. Sitting 2 ft away is a 40 gallon tank, piped into the coil, with a circulator in the loop. I look at that and think that there must be a simple way to use a second smaller dhw flat plate hx to replace to coil in the boiler and then I could let the oil boiler go cold when I'm burning wood and make use of the tank and circulator that's already in place.
Does any of this make sense?
OK - From your description above, it sounds like you have an indirect tank already. The circ is pumping water in a closed loop between the coil in the boiler (where it is being heated) and the coil in the 40 gallon tank. If I am wrong, then please straighten me out. There should be some means for expansion on that circuit as well. I have not seen a setup like that before.
Now, how are you going to keep water from passing through your furnace? If you are putting an HX on the return leg of the zone manifold before it gets to the boiler, then are you adding a bypass circuit to send the heated water to the supply leg of the zone manifold? If so, then the boiler will go cold, and you cannot heat the DHW via the coil in the boiler.
However, rather than buying another small HX, why not just pipe the circ you are already using on the DHW loop to circulate the heated water from the supply leg and then back to the return leg (before the HX)? The extra piping is going to be cheaper than the HX, and the amount of work is probably the same or less than adding another HX.
BTW - if you completely bypass the oil boiler as above, how are you going to handel backup situations? Unless you are using motorized isolation valves, you will have to manually open the circuits to allow flow through the oil furnace again. You will also have to shut down the oil furnace electrically, too.
Rick Stanley said:Hi Jim,
No, it's just a storage tank. I think it's an electric water heater that's not wired up. Instead, it's contents are circulated through a coil in the oil boiler. So, I just was wondering, that if I did decide to let the oil boiler go cold, if a second flat plate may be a good option.
I'm really torn, still, about all of the options and go back and forth a lot. Right now, I'm pondering the Eric Johnson approach. He shuts his fossil fuel boiler off, plugs up the flue and BURNS WOOD, period, during the winter. Because of the way it's piped he does keep his propane boiler hot with Eko water, but he has to change over manually if he's away or something. I could live with that, I'm here all of the time anyway. I think he built a side-arm hx for hw.
Anyway, thanks for helping me try to figure out whatever it is that I'm trying to figure out :lol: I can just picture people reading my questions and wanting to help but end up shaking their head saying "I can't tell what he wants to know"
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