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[intensedrive]

From reading this forum over a few years, I have always read a faster pump speed means more heat delivered to the home through the exchanger.  I believe I have a small taco pump, it has three setting.  I normally run it on second setting.  Just for fun I turned it down to the first setting and the the air from the ducts seem much warmer.  Maybe it's in my head.  I would like to hear more comments on pump speed and heat delivery through the water to air exchanger.

[E Yoder]

It'd be interesting to know the pump model, piping distance and size, etc.
But lower pump speed means a lower volume of water delivered to the coil, which means part of the coil would be using cooler water... Should equal cooler air. But depending on the piping distance it might not be a noticable drop in flow rate. In other words depending on the size of the coil it may only need 4 gpm, and you may have dropped from 7 to 5 gpm. (Possible scenario). Then there'd not be any difference, and the stove temp at the moment of testing would be the only variable.
I can't think of a scenario where less water would equal hotter air.
My rambles anyway...

[greasemonkoid]

The pump cavitating at higher rpm. That's what pops in my mind, but the odds of that happening with common, modern pumps probably makes it not worth mentioning.

[mlappin]

If, and I say IF the pump is in your basement and you turned it down one click then it was caveating before and wasn’t moving as much water on speed two as it is on speed one. If its mounted on the back of the boiler then ignore this.

[Radio Tech1964]

Possible scenario for altering pump speed... My install called for using several elbows due to the air handler location,outside access and such.
The actual piping footage is less than the previous 60 feet. I haven't measured exactly yet but I'm guessing with all the bends I had to use to gain access to the air handler location that it's roughly 30 -40 feet max distance using 1" pipe.

This is a manufactured housing home as in double wide 24X60 so I will probably need all the output I can get,especially considering the climate here which has been downright cold a few nights already

So would it be of any benefit to move to the highest speed ?


Thanks!

Wt

[E Yoder]

Checking the difference between supply and return water temps will tell you if you could benefit from more flow. Anything over 20F difference could use a higher pump speed and cut down on air handler run time possibly..

[Radio Tech1964]

I'll check the differential between supply and return when I get it fired up and see what that says.
May also have to change the blower speed providing the motor has taps for this. I'm afraid the standard heat only blower
in this rig runs at a fixed unchangeable speed.


Thanks for the help!