return water location

mswilks

New house to me. Like the system. Hot water rises, cold water sinks. Was looking at the zonal pumps and noticed the returns for each zone are directly under the supply for each zone rather than at the bottom of the entire system. I'd like to know if this would make a significant difference in performance of the system. The bottom two zones are on individual thermostats, top zone circulates all the time.

Jamie Hall

And, I presume, that whole manifold is fed by another pump from boiler, and returns to it? That's a very common, and very good, arrangement for a zoned system. It ensures that there is adequate through the boiler at all times, and yet that there will be adequate flow through the various zones when they need hot water.

mswilks

yes a taco 007, the top zone is definitel warmer than the bottom one so im wondering why the return(s) arent all at the bottom of the system. Very cold climate in Eastern UP MIchigan, so want to know if rerouting the returns will make a big difference

EBEBRATT-Ed

@mswilks

The did not manifold it correctly. The should have come off the main wit1 1 tee and fed all the supplies and then a second tee for all the returns.

The way that is piped the upper zone return water coolds the next zone depending on which way the water flows in the main. Either way it could have been piped a lot better

mswilks

supply comes in from the top, return on the bottom of the main stack on the left. It's pretty easy to reroute the returns, BUT I'd like to know if it will make a big difference or not

Mosherd1

Are the heat emitters all the same throughout?  Or does the top manifold feed fintube baseboard, the next section feed cast iron radiators, and  the last manifold feed radiant floors? It’s possible it was set up this way purposely to supply cooler water to the lower manifolds, but if all your heat emitters are the same style throughout the building, it can be reconfigured to supply the same water temperature through out. 

mswilks

the middle zone has radiant floor (between joists in the basement) and one radiator on that zone. All the rest are radiators. I can balance them reasonably, and I like the fact that each one returns directly. Looking to know if rerouting the returns to the bottom of the stack will give me some more efficiency. This was added about 15 years ago to a 1902 house.

hot_rod

Looks like you have a series primary loop. If so each set of tees will see a lower supply temperature. This is not a problem if different SWT are ok as you go around the primary loop.
The biggest "win" is the various pumps are hydraulically disconnected.

If for example every connection or distribution circuit needed or want the same SWT, a parallel primary/ secondary piping may be a better fit.

How is the building working as far as heat? Comfortable in all the rooms or zones?
The key will be when you are at design condition, the coldest days of the heating season. That is typically where a series loop can fall behind when all zones want the same SWT.

Time, and high load conditions will be telling.

mswilks

today its -10. The lower floor is running 4-5 degrees cooler than the thermostat is calling for, and the boiler is running at 185, the max supply temp. the upper zone which supplies the radiators primarily on the second floor are mostly shut. I know the system isnt optimum, but I'm really trying to figure out how much I would gain if I rerouted the returns into another stack. The end game is I'm also trying to figure out if the boiler is capable enough, and before I make that investment it would be good to know how much I might gain by rerouting the returns. Thanks for all the comments, they are helpful.

mswilks

FYI, the system has been cleaned out with Rhomar cleaner.

pecmsg

Is the second-floor open to the 1st?

With my second floor at a lower set point the heat runs up the stairs and barely maintains the temperature.

mswilks

no, only 1 radiator heats the entry way and stairs. 90% of hte lower floor is not exposed to the stairs.