Circulator Energy Consumption

SENWiEco

I am working with a vendor to flesh out the 'near boiler' configuration of my hydronic heating/cooling system. As part of this system, I will have a chilled water coil installed into the HRV intake duct. The purpose will be to condense out humidity as needed (latent load) during our very short cooling season (shorter still for me due to high performance building envelope). It is likely that this condensing system would be running less than a month a year.

The vendor has suggested an "EC Circulator on autoadapt / constant pressure mode which stays on all the time and fires-up in response to pressure drop". They then suggested adding a zone valve to the circuit to control the 'on/off' times.

I am trying to find out what the standby energy consumption on a setup like this would be.

I was expecting to just install a circulator that was controlled by a relay and turned on and off as needed for condensing.

I am assuming the constant pressure is needed in this single fixed length circuit because the pressure drop of the condensing coil would increase as it ices up before dropping during a 'thaw' cycle.

Thoughts?

hot_rod

Is there more than one loop of circuit involved? If not really no reason to have a circ with a single zone valve? You would have the energy consumption of a transformer in the relay, running 24/7. what is the source of the chilled water?

ECM circulators draw around 7W in standby or idle mode. Do electric meters even register a 7W load?

Dave H_2

The MOST efficient circulator is the one that is off!

Add a zone valve instead of a relay so you don't get unwanted flow in the system? I would rather shut the thing off!

DaveH.

Big Ed_4

You can't hurt to add or connect to and outdoor thermostat when using a constant circulator . Then you get the best of both ...

SENWiEco

@hot_rod - yes there is only one loop for the condensing system. The chilled water will be created by an outdoor heat pump (probably Goodman) and the ThermAtlantic DX2W-2 indoor unit. I had not heard of the autoadapt/constant pressure circulators and am not sure why they think it is needed here. I think I would prefer just turning the circulator on and off as needed, especially since it would be off for the vast majority of the year.

hot_rod

SENWiEco said:

@hot_rod - yes there is only one loop for the condensing system. The chilled water will be created by an outdoor heat pump (probably Goodman) and the ThermAtlantic DX2W-2 indoor unit. I had not heard of the autoadapt/constant pressure circulators and am not sure why they think it is needed here. I think I would prefer just turning the circulator on and off as needed, especially since it would be off for the vast majority of the year.

I agree, you could use one of the ECM in a fixed speed, is saving some electrical consumption is a concern