Same as a smaller pump?

mac

Here's the scenario: Need incredibly small pump for 3 small loops of climate panel, roughly need 3 gpm @5' of head. I have a Grunfos 15-58, speed 1 is way to much, was running with about a 2* delta T. In lieu of changing (finding?) to a much smaller pump, can I simply wire in a 120V dimmer (rheostat?) to "turn down" the pump speed?

Thanks in advance!

JohnNY

low flow

Why not just pipe a bypass around that Grundfos?

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mac

Its already piped..

and I thought, "hey, what if the power is modulated down, like with a dimmer/rheostat??

jeff_51

no

A dimmer switch works by decreesing voltage. You are essentialy "browning out" your pump, and that In't good. You can get a switch that slows down the 60 hz cycle to whatever you dial it down to, to slow down the pump, but leaves the voltage at 110/120. These can be gotten at most any supply house that deals in hvac. These are used in commercial applications all the time when you need to cool in cold climes

Rich Corcoran_25

Dimmer

The preferred way to dial in your pump is to use a valve to provide addtional head to the pump. You can dial in the flow to achieve your desired delta T.

RC

[Deleted User]

Why worry about it???

If you're not concerned with the parasitic cost of operation, which is minimal at best, let er rip!.

Choking flow to see a greater delta T will not necessairly deliver more energy.

Riddle me this. Which delivers more energy. A pipe flowing 100 GPM @ 1 degree delta T or a pipe moving 1 GPM with a 100 degree F delta T...

The panel will deliver its load based on the AUST differential. Having a low delta T across the panel actually has the potential of delivering more energy to the space than a panel with a large delta T...

Maybe the good Dr Bean will step in here and give one of his wonderful analogies.

PS, I've used dimmers on small circs before, and boy, are they NOISY! BUZZZZZZZZZZ.

ME