Still getting some circulation noise.

PDB2

If anyone would take a look and see if I've made some basic errors in near boiler piping that would cause noise to radiate thru my baseboard zones. At first I thought I had oversized the pumps and noise was from excess volume, so I changed one zone pump, these are pump controlled zones, from a 007 f5 to a 006 f4 taco. Doesn't seem to have made any difference....I've bled system every way I can think of and even added an extra auto air vent at the very top of the zones, still no help.

Photos @ <a href="http://postimage.org/gallery/6asgth7y/">http://postimage.org/gallery/6asgth7y/</a>

gennady

piping

Hello, in my opinion it is very wrong. feeder and expansion tanks must be installed in point of no pressure change, 12 diameters of the pipe must be straight on the pump discharge and so on. you will have re-do all piping.

furnacefigher15

How much

Baseboard is connected to each zone? What size pipe is used for each?



From pic I see two zone pumps with 1 supply each, but I see 3 returns connected on the return header.

Gordy

It would appear

That there are only 2 zones each zone has its own pump. Technically poster is pumping away from the PONPC, Not usual component arrangement though. Lots going on with short pipe, and elbows in such a small space..........velocity noise I suspect from abrupt changes in piping.





Gordy

PDB2

Ok....

So you're saying the location of the expansion tank is wrong on the return, or the pipe size is wrong connecting it ? And the elbows at pump discharge not kosher ?

Both zones are baseboard, 3/4 in. copper lines. There is only 2 returns and the other is an auto fill supply.

furnacefigher15

baseboard

How much basboard in feet on each zone?

Gordy

Need the details

Furnace Fighter 16 is asking how many feet of baseboard in each zone. This info is needed to determine if the pump is to large. You need to give the distance from the boiler, and back for each zone, and pipe size to calculate head loss to see if the circs are sized properly.



 You are pumping away from the PONPC should be fine. Normaly the xtank, and water feeder are on the supply side of the boiler, and the pumps after the xtank.

PDB2

details

I've got one zone @142' with 26 fittings, and the other is 134' with 32 fittings. The taco 007 came with the boiler package so I bought another and zoned with the circulators same way the old boiler was plumbed. Changing the one zone to a 006 pump didn't seem to change the noise or the temp drop on that zone much....still around 35 degrees.

The location of the xpan tank and circulators are pretty much as shown in the Weil-Mclain install manual diagram for high temp, circulator zoned application .

It is piped tighter than than the old system (B&G 100's) was as you noted, and if that is answer to the noise problem I'll find a way to spread it out even though I haven't a lot of room to work with.

Gordy

Pipe diameter

Need to know pipe diameter also. Is the footage from the boiler, and back?

gennady

green taco

Green taco pump appears to be pumping  from top to bottom direction, and it will be air bound, also it appears that it is pumping into expansion tank. expansion tank with feeser line must be connected to tee on the top of the boiler where pumps inlets connected. but it is also a boiler discharge, so it is wrong place for placing pumps or exp tanks. this is just my opinion. this is highest temperature in the system and you made it lower pressure point by making it suction for the circulators. Not a good combination.

gennady

green taco

Green taco pump appears to be pumping  from top to bottom direction, and it will be air bound, also it appears that it is pumping into expansion tank. expansion tank with feeser line must be connected to tee on the top of the boiler where pumps inlets connected. but it is also a boiler discharge, so it is wrong place for placing pumps or exp tanks. this is just my opinion. this is highest temperature in the system and you made it lower pressure point by making it suction for the circulators. Not a good combination.

Gordy

estimation

IF its 3/4" cooper, type L, adding 50% for fittings, and footage is from boiler, and back I get 8.85 feet of head at 5 GPM that's the upper limit for velocity on 3/4" copper pipe. Whats the delta t on supply, and return for the loop? If its low your over pumping should be about 20*.



A series 100 circ has a flatter pump curve than a 007 I think a 007 is to big.

furnacefigher15

8.5 to 9 feet of head

is pretty close to restriction of flow in both circuits, could be as high as 12 with all those fittings (seems like a lot).



"I've got one zone @142' with 26 fittings, and the other is 134' with 32 fittings. The taco 007 came with the boiler package so I bought another and zoned with the circulators same way the old boiler was plumbed. Changing the one zone to a 006 pump didn't seem to change the noise or the temp drop on that zone much....still around 35 degrees."







http://www.taco-hvac.com/uploads/FileLibrary/curves003-008.pdf



http://completewatersystems.com/wp-content/uploads/2011/04/149.pdf



Do you get Heat? The pumps are at there limits in head capacity, and may not be moving any water. The head may be high enough for the pump to act like it is being dead headed, and that may be the cause of noise.



35 degree delta is high and indicates low flow.



Were there any other changes to the system other than just the boiler?



Is this a completely new set up baseboard and all?



If my suspicion is right, the 006 pump probably made the problem worse (less head capacity)



Before buying new pumps, I would try putting the 006 and the 007 (that was removed and you hopefully still have) in series. This will cause the total head capacity to be closer to 18 instead of around 8 (for the 006) and 10 (for the 007). The gpm capacity will not double, but stay the same / or average between the two.

Gordy

Is noise more pronounced

  If both zones are calling for heat, or just one, or is there no difference?



Gordy

PDB2

more info, and thanks for responses....

The green taco doesn't pump to the xpan tank....just looks that way. But it is circulating in down direction. Didn't think it was an issue as the old setup with he 100 series were similar.

The 35 degree drop seems to change to a 30 drop later in the cycle as the room temps rise toward thermostat settings. Both zones stay within 3-5 degrees of return temp tho, even with the smaller pump on the one zone.

I probably should have gone deeper into pump sizing than I did, but thought the series 100's and 007's were pretty close. Maybe should have kept the old B&G's in hindsight, but the motor's were original 50 yr's old....think I changed the pumps maybe 20 years ago.

I made no changes to system other than near boiler piping on the new boiler. The new boiler is a series 3, a little smaller than the old one, but a couple notches more efficient.

Everything is working Ok and we seem to have plenty of heat so far, so I guess other than changing the one zone back to the 007, I'll let it go for this season. Maybe the worst that would happen is burning up a pump if they are in fact undersized. Another thing on the pump sizing was not finding any information on what the baseboard sections output were. They have aluminum fins but no brand name I could find. I had to assume they matched the heat load requirements but at what volume?



So based on what I've learned here I should :

-recheck pump sizing

-change pump position and clean up pump discharge piping . Would increasing size of elbow at discharge help that, or does it require the 12x pipe diameter straight run no matter what ?



 

PDB2

and Gordy.....

forgot to mention....the zone with the most noise is the one with the down direction pump position. The noise level doesn't seem to change much with both zones circulating

Gordy

Velocity noise

the pump orientation is would be fine if you had more straight pipe before and after the 90's. Your getting. Velocity noise from the abrupt changes in direction which is resonating through the system.





Is the delta t at the base board loop or the boiler?

Need the base board delta





Gordy

Gordy

Varying delta t

Should be said if the system is cold start, and the dwelling is being brought up from low set point say setback, or maybe house is cold because you were installing boiler. You will have a wider delta t than if the dwelling were up to set point, and boiler is maintaining that set point.



20* DT is a design parameter usually used in rads, baseboard emitters. Rarely will you see that 20* through a heating cycle. It depends on conditions.



 IF you are seeing 30-35  supply, return on the baseboard loop you are under pumping....But do your temp measurement at a couple different times in the heat call. Beginning, middle, and near the end. You will see that delta t gap close up.



Also compare the pump curves of the B&G series 100 circ, and the 007 taco. You will see that the 007 is capable of more head than the series 100.  So IF nothing has changed except the near boiler piping from before, and everything worked fine before the 007 should be plenty big.



Gordy

PDB2

delta t

The temp difference I'm using is the boiler set point (180), minus what I'm reading with some strap on gauges at the loop returns, 12" before they combine at the boiler return.

Maybe not an accurate enough method ?

Gordy

Close enough

Thats fine

SWEI

Series 100

Curve on a Series 100 is a close match to the Taco 0010.  0010 tops out at 10ft instead of 8 ft, but most of the working portion is a near-perfect match.