circ pumps vs. zone valves

bovide_2

for a 3 zone residential hot water heating system, which is better: three circ pumps w/relays, or one pump w/3 zone valves? No radiant - standard baseboard radiators only.

ta finnegan

Opinions.....

Personally I like to zone with circulators, then you can avoid the possibility of a larger circulator making velocity noise in a small zone.

Some zone valves are problematic, the Taco valves are nice, so are the B&G.

It costs less to zone with valves, but I don't think performance wise you can beat the circulator.

Primary loop around the boiler, pump away with primary circulator, size circulators in secondary zones to the load, relay panel, you are off and running.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Boilerpro

I have started leaning towards zone valves...

Because of the electical consumption of multiple small, low efficiency pump motors. This is especially the case when using reset water supply temperatures. With reset, most of the time all the zones are on, so a single pump would be more efficient. Multiple pumps are nice for back up though.

Boilerpro

Mark J Strawcutter

velocity and cost issues

A differential pressure bypass should solve any velocity noise problems when only a small zone is calling for heat.

I was surprised that a Honeywell zone valve was slightly more expensive than a Taco 007 at my local supply house. Not sure how labor, controls etc would affect total cost.

Mark

Unknown

zone valves are the work of the devil

ok, maybe not quite.. but really, cost of a zone valve is comparable to a taco 007 or Grundfos Brute series pump. Zone valves fail more often, you have to think about balancing, and you are running a larger pump then you have to whenever fewer zones are calling for heat.

Overall you probably use a bit more electricity, but flow and performance are easily predictable and maintenance is less with pumps. I can't think of too many situations where I would prefer to use a zone valve.