Is my pump too big. Circulator velocity noise.

Le John

Hello all. Spring is almost upon us……

I have a tenant apartment that has roughly about 50 feet of Baseboard (supply and return are in 1/2 inch copper) that has a Taco 007E. The tenants are complaining of velocity noise and keeping them up at night. I do faintly hear it. I believe the apartment needs about 30K btu's. There are no complaints about heat just the noise.

Would it beneficial to change the Taco 007E it out for a smaller pump? I don't understand pump curves and would appreciate any guidance.

LRCCBJ

The velocity in 1/2" is only about 4 ft/sec with the 007e so it is unlikely they are listening to "velocity noise". When is the last time the zone was purged?

Le John

@LRCCBJ - Maybe about a year?

hot_rod

Are there multiple zone valves on the system?

Once you get to 5fps feet per second velocity you can start to hear some noise from the flow'

In 1/2" copper M that would be 4 gpm or more.

Is there a way to adjust the speed on that model?

It looks like it is designed for multi zone valves and adjusts on a delta P condition?

GroundUp

It's highly unlikely that the noise is velocity related, unless there is some sort of orifice or valve further reducing the diameter and therefore raising the velocity… Is it all 1/2" element as well or just the supply and return piping to the element?

LRCCBJ

https://forum.heatinghelp.com/discussion/comment/1847470#Comment_1847470

I would first attempt to purge it as it takes only 10 minutes. The tenants might be listening to air in the line.

Also, if you have a ball valve anywhere along the flowpath, close it down to about 30 degrees (90 being fully open). This will absolutely slow the flow rate and allow you to determine if they are listening to velocity noise.

Le John

https://forum.heatinghelp.com/discussion/comment/1847471#Comment_1847471

@hot_rod No Zone Vales. 2 zones with two Taco 007-e

1 007-e does the 2 bedrooms roughly about 80 feet of baseboard. Another 007-e (zone 2 Does a kitchen , living room and dining room. All is in 1/2 copper.

LRCCBJ

https://forum.heatinghelp.com/discussion/comment/1847471#Comment_1847471

He cannot get to 4 GPM on 1/2" copper (estimated 75 ft EL) with a 10ft limit of the pump.

Almost impossible to be velocity noise at 3.5 GPM……….which is the maximum possible flow rate.

hot_rod

80' fin tube at 500 btu/ft = 40,000 btu/hr. If in fact that is what the load is, 4 gpm at a 20∆, not realistic with all 1/2" tube?

1/2" copper recommended max. flow in most hydronic design guides is 1.5 gpm

If you have 80' of fin tube plus piping and ells, call it 120' EL

If you are only flowing 1.5 gpm, at 20∆ then you are moving 15,000 btu/hr.

techforlife

Is the IFC installed? 007E comes with one in the box. If it has a Flowvalve, you don't need an IFC.

LRCCBJ

https://forum.heatinghelp.com/discussion/comment/1847487#Comment_1847487

You cannot flow 3 GPM through 1/2"M with a 007e at 120 EL. Not even close.

The load is irrelevant to the discussion. A higher flow rate (possibly 2.5) simply results in a smaller DT.

Clearly, he does not have 80' of element. That's ridiculous.

Le John

I'm heading back to the property tomorow and I'll purge the zone as @LRCCBJ suggests. As far a 80 feet of element its more like 63. there is 25 feet of element in each bedroom and a 12 feet run in a hallway.

appreciate all the comments.

hot_rod

regardless if it is 80 or 120’ EL the pump is not causing excessive velocity

A valve that is partially opened can cause a hissing noise, any tight restriction in the piping actually. Maybe an isolation valve that didn’t open fully?

If the home maintains temperature on the coldest days, you have enough fin tube, regardless of the actual gpm

Le John

https://forum.heatinghelp.com/discussion/comment/1847538#Comment_1847538

here is a recording of the noise. The other pump is silent.

Circulator noise through pipes.m4a

GroundUp

Sure doesn't sound like a velocity noise, but I'll ask for a third time if there are any orifices or valves that may be partially restricting the flow? This could potentially cause a high velocity area and therefore some noise. The noise in the clip sounds more like a bearing than anything, but it's hard to say without being there to listen exactly where the noise is originating from.

pecmsg

pumps are cheap
Change it and see if the noise goes away

Le John

https://forum.heatinghelp.com/discussion/comment/1847626#Comment_1847626

@GroundUp I don't see any restrictions. All valves are fully open and the other TACO 007-E doesn't make the any noise.

Dave H_2

So, to quickly answer your question about a smaller circ, the 007e is a variable speed delta P circ, so it is running slower based upon the system that is connected to it such as yours with 1/2".

There are times I hear harmonics in the pipes in a house and sometimes the quickest and easiest fix is adding a pipe clamp on a long run that you can see and rteach