Can a 007 circulator output be slowed down?

Russ_11

I have a Taco 007 circulator supplying a small modine heater in my garage. The circulator appears to move the water too fast through the circuit not providing enough time for proper heat transfer. Can the 007 circulator be controlled to slow it down? I have a 003 bronze circulator supplying a wall heater in my basement and it works great.

Alan(OnVacationInOregon)Forbes

You could

do a few things:

1) Install a ball valve or some fancy flow setter on the discharge side of the circulator.

2) Shave the impeller so that it doesn't grab as much water.

3) Change the cartridge, perhaps down to a 005.

Bernie Riddle_2

What about using a dial dimmer switch to reduce the voltage to the pump and slow it down? They can be bought at the hardware store cheaply and easily wired inline and then you can at least figure out weather it will help your situation or not. I have done it on some pumps in my house messing around with flow and even have one on a bell and gosset pump that cools a compter system (long story in itself) and it runs 18hrs a day and has benn set up like that for 4 years......

Ken D.

007

Many radiant systems use modulated 007 circs. Controls such as Tekmar will slow it up. Perhaps they can be configured for the application you describe. Check with your supplier for advice. You could also install a bypass line to redirect most of the flow around it.

mark schofield

inductive load?

That's a neat idea. But on an inductive load like an AC motor, would a decrease in voltage result in an increase in amps which might overheat the motor windings?

John McArthur_2

Doesn't a dimmer switch (rheostat) vary the current rather than the voltage?

It's been a long time since school, I can't really remember.

[Deleted User]

Things are not always as they seem...

Russ, in your post you said,

"The circulator appears to move the water too fast through the circuit not providing enough time for proper heat transfer."

The only way you can tell if the water is moving through the circuit TOO fast is if there is residual noise from the piping serving that circuit. You'd hear a continuous HISSSSS, which is excess velocity.

As far as the coil is concerned, the water can NOT go through it too fast, In fact, the faster the water goes through it, the higher the average temperature across the coil, the greater the average differential in temperature between the entering water temperature and the entering air temperature, the greater the delivery capacity.

In other words, if water enters at 180 and exits at 175, average coil temperature is 177 degrees F. If water enters at 180 and exits at 160, average coil temperature is only 170 degrees F. If entering air temperature is 60 degrees F in both cases, then in example 1, your air to fluid delta t is 117 degrees F, and in scenario 2 it is only 110 degrees F. The greater the delta T the greater the delivery capacity. THis would be confirmed by looking at the air side delta T.

Iknow, I know, in your minds eye, the btu's are whipping around too fast to hop off the btu train, but trust me on this, its different than what your minds eye is seeing.

Unless you are hearing hydraulic hissing noises, I seriously doubt that you are moving water in excess.

If you can give me some kind of an idea of the length of the circuit, pipe size and fitting count, I have software that can calculate to the Nth degree how many GPM you are moving, and based on delta T, how many btuH you are delivery. Need the coils pressure drop data as well, and a simple piping schematic would be helpful as well.

As for the use of a rheostat, I have tried that before, adn it performed the function I was looking for, but the electrical noise associated with its operation is horrendous. The slower the speed, the more the noise generated. Kind of a real low groaning/buzzing sound that would drive you up the wall. Not recommended. The only way I could recommend doing it would be through the use of a triac relay in a manufactured product, like Taco's variable speed controller based on delta T, but YOU have to come up with the signal inverter to produce the 0 to 10 VDC signal to control the pump.

Wilo will be coming out with something soon taht will have the ability to perform that function, but economics may be an issue.

Now, if what you are trying to do is increase the discharge air temperature from the FCU, you can do one of two things. Raise the operating temeprature of the fluid circuit, or decrease the air flow across the coil, thereby creating a larger delta T on the air side. The problem with the first suggestion is that it may take a condensing boiler out of its ideal condensing range, and doing the air flow slow may affect face velocity and throw thereby creating drafts within the room.

If you want to experiment, try choking the water flow to the coil. It should not make that much difference in delivery performance, but to kill your curosity, its the least expensive thing to do, and the pump can handle it.

ME

Jim Bergmann_2

current vs voltage on the pump

You would only be correct if the same amount of work was done (watts consumed by the pump). Because the voltage drops so will the motor speed and the current. Simply, the motor is moving fewer pounds of water, which requires less work. If the work the motor did was the same, the power used would be the same also and the current would have to go up as the voltage dropped. I also have pumps on a rheostat in the shop to mimic different flow conditions, no problem for the past three years.

Maine Doug_59

One of my

eight 007's has been running slowly on a tekmar control for the variable speed injection floor loop since 2000. You can hear it change speeds if you change the setting on the globe valve to make it work harder. So far so good.

Perry_3

Variable Frequency vs Variable Voltage

It all depends on what kind of motor this is - and I'm betting that variable frequency is needed to slow the pump down.

If this was a DC motor - with brushes transmitting current to the rotor - then by varying the voltage to the motor will vary the speed (this is how variable speed portable drills work). The trigger octuates a rheostate that varies the voltage.

A dimmer switch also varries the voltage to a light bulb.

In both cases; varying the voltage does also vary the current (amps).

However, for an induction motor (no brushes) - where the current is induced into the rotor you vary the speed of the motor by varying the frequency of the supply current. That takes a special controler which first converts the input AC (be it 50 or 60 cycle) in to DC - and then electronically produces whatever "AC" frequency is needed to properely control the speed (and capacity) of the pump.

Given that these are a fluid rotor pump I will bet they are induction motors as I don't see how you could have brushes in there.

Thus, you would need a variable frequency drive controller.

Perry

Brad White

What Mark Said

Especially about the velocity not affecting transfer. As Mark pointed out it increases it by raising the average water temperature but also enhanced by turbulence. If noise is not an issue and the perceived excess flow does not affect other zones or the system in any bad way, I would not change it.

A balancing valve on the return is the simplest way but Taco and others do offer variable speed controlled versions of their normal circulators. Be prepared to pay several hundred dollars for the honor of doing so.

S Ebels

This is a recurring thought

And it's not right. From time to time the comment is made that the water is going "too fast" to give up it's heat. While at first glance it may appear that the water is not giving up any heat due to temps being the nearly the same in/out, what's really happening is that the flow rate is exceeding the abilitiy of the emitter to "liberate" the heat.

Think about it. If you have 30 feet of BB that's running nearly the same temp for it's whole length, is it not going to produce more heat than the same length with a 20* drop?

The concept that the small temp drop means no heat transfer is incorrect. One could say that the the emitter is too small for the flow rate and that would be more accurate. The emitter is going to do what it does based on the water temp in it. You can see this if you look at a chart of output/water temp for any manufacturers baseboard. As the avg water temp drops the output goes down, not up.

Kal Row

you hit it!!!

the future will be brushless dc Electronically Commutated pancake Motors (ECM’s) with the permanent magnets laid out radialy in a circle instead of axially in a sleeve – gives it more leverage at slower speeds, and allows for better control of the motor’s reluctance, – in fact, ac versions of such a motors are know as switched reluctance motors and are extremely quiet

the arrangement will be nice and compact, with the electrical connection coming off the middle of the pancake – real neat and easy to service - and only one center bearing

as more people adapt ziggi’s mini-tube injection method – manufactures will have to no choice but to adapt

I have a mini-tube job right now with 14 taco “vs” pumps – that I wish were ECM’s

Bernie Riddle_2

> That's a neat idea. But on an inductive load like

> an AC motor, would a decrease in voltage result

> in an increase in amps which might overheat the

> motor windings?




I am no electrical engineer or even a plumber by any means but from what I have fooled around with in my own home, It does give you great control over the flow rate on circulators. If nothing more the a cheap way to trouble shoot one temporarily, and does not seem to have any adverse effects on them. I left a 011 reduced with a dimmer switch for over a month and it worked fine. (I am the original poster about the dimmer switch.)

Beats buying a smaller circulator and finding out it doenst work!!!

Bernie Riddle_2

identity thief

Listen Tinkerer What a shame you cant get a life of your own and not be useing mine,what a pity "DAN" can't do something about this identity HI-Jacking.

SO you all know the original "BRENDAN" post on this thread even though it bares my name/e-mail address was sent by another.

Please be advised as a result of this behavour which in the past included derogitory remarks,I will not be using this site again.

Brendan Burke

Bernie Riddle_2

sorry to ruin your day......

Well, trust me I wasnt TRYING to steal your identity if thats what you mean. I replyed and even ADMMITTED I was the one who posted that and didnt realize I needed to change the fields at the top so if you think thats "trying to be like you" then I am sorry to ruin your day..........

And ya I am a "tinkerer" and dont break out the "Hydronic heating bible" every time I have a problem.......

GaryDidier

007

Sounds more like the modine is air bound. Do you have it set up for purging or have an auto air vent installed?
Gary from Granville

Russ_11

Didn't seem till I saw

> Russ, in your post you said,

>

> "The circulator

> appears to move the water too fast through the

> circuit not providing enough time for proper heat

> transfer."

>

> The only way you can tell if the

> water is moving through the circuit TOO fast is

> if there is residual noise from the piping

> serving that circuit. You'd hear a continuous

> HISSSSS, which is excess velocity.

>

> As far as

> the coil is concerned, the water can NOT go

> through it too fast, In fact, the faster the

> water goes through it, the higher the average

> temperature across the coil, the greater the

> average differential in temperature between the

> entering water temperature and the entering air

> temperature, the greater the delivery

> capacity.

>

> In other words, if water enters at

> 180 and exits at 175, average coil temperature is

> 177 degrees F. If water enters at 180 and exits

> at 160, average coil temperature is only 170

> degrees F. If entering air temperature is 60

> degrees F in both cases, then in example 1, your

> air to fluid delta t is 117 degrees F, and in

> scenario 2 it is only 110 degrees F. The greater

> the delta T the greater the delivery capacity.

> THis would be confirmed by looking at the air

> side delta T.

>

> Iknow, I know, in your minds

> eye, the btu's are whipping around too fast to

> hop off the btu train, but trust me on this, its

> different than what your minds eye is seeing.

> Unless you are hearing hydraulic hissing noises,

> I seriously doubt that you are moving water in

> excess.

>

> If you can give me some kind of an

> idea of the length of the circuit, pipe size and

> fitting count, I have software that can calculate

> to the Nth degree how many GPM you are moving,

> and based on delta T, how many btuH you are

> delivery. Need the coils pressure drop data as

> well, and a simple piping schematic would be

> helpful as well.

>

> As for the use of a rheostat,

> I have tried that before, adn it performed the

> function I was looking for, but the electrical

> noise associated with its operation is

> horrendous. The slower the speed, the more the

> noise generated. Kind of a real low

> groaning/buzzing sound that would drive you up

> the wall. Not recommended. The only way I could

> recommend doing it would be through the use of a

> triac relay in a manufactured product, like

> Taco's variable speed controller based on delta

> T, but YOU have to come up with the signal

> inverter to produce the 0 to 10 VDC signal to

> control the pump.

>

> Wilo will be coming out with

> something soon taht will have the ability to

> perform that function, but economics may be an

> issue.

>

> Now, if what you are trying to do is

> increase the discharge air temperature from the

> FCU, you can do one of two things. Raise the

> operating temeprature of the fluid circuit, or

> decrease the air flow across the coil, thereby

> creating a larger delta T on the air side. The

> problem with the first suggestion is that it may

> take a condensing boiler out of its ideal

> condensing range, and doing the air flow slow may

> affect face velocity and throw thereby creating

> drafts within the room.

>

> If you want to

> experiment, try choking the water flow to the

> coil. It should not make that much difference in

> delivery performance, but to kill your curosity,

> its the least expensive thing to do, and the pump

> can handle it.

>

> ME

Russ_11

Didn't seem till I saw

Mark, Thanks for the detailed insight (which I understood entirely) and perception clearing. It didn't occur to me about the temperature of the incoming air and the affect it had on the output temperature. I decided to verify that theory and with the temperature of the garage at two different temps 40 & 65 degrees I tested the output air temp of the Modine and when the garage is colder the air appears to be colder, as if there was not enough heat transfer, even though I had almost the same coil temp. The boiler maintained 170-175 water temp the whole time. Restricting the flow with the shutoff valve had no affect on the temp/heat transfer. The heater is working fine.

Russ_11

007 good

See my post above. The circuit is free of air. I just wasn't paying attention to the ambient air temp.