Cross 8 Manifold or 8 Pumps?

watercourse

Is it crazy to put a pump on each zone?

Also, what's your take on Cross manifolds with their integrated controls?

HomerJSmith

It depends upon how you want to regulate each zone. Zone Valves, manifold or Circulators??? That is the question.

Consider an ECM pump with Zone Valves. A multi speed fixed pump with the manifold as flow is regulated with manifold flow valves. With Cross manifold thermo acuators and contolling thermostats, I would consider an ECM pump.too

Zoning with circulators is probably as expensive as ZVs as you would need balancing valves to regulate the flow thru each circuit. Cost wise electricity usage with circulators would be greater. Using a manifold is the way I would go, I think even tho it may be more expensive up front.

I have never used a Cross manifold. So, caveat emptor. Mechanical manifold controls can fail over time. I would consider a fixed manifold with thermo acuators if needed like Caleffi twist flow.

GGross

I sell Cross manifolds. So far no problems that were not installation related, and when you call up there for info a lot of times you are talking to the guy that owns the company. One guy broke the drain fitting and when I called they said "we don't have a part number for that, they never broke before" I sighed because its a tale as old as time, thought they would tell me to get a new one. Nope! They sent 2 new drain fittings out to me that day no charge, an extra one just so I would have a spare.

I say go for it.

TAG

My last project used three Cross Manifolds and one Bluefin w/ a zone valve. This is the third season -- the Cross are very slick and nicely made. The bluefin manifold is used to supply water to a single room of subfloor plates -- so there was no need for individual zone controls. The other three manifolds needed various zone (loop) control. When you add up the thermo heads for most manifolds the higher cost of the Cross starts to come down and if you need full control of say an 8 loop manifold -- they are cheaper. Another nice thing about the Cross is they come with the control and transformer -- all you have to do is connect up the thermostat. So ..... no additional parts and there is no extra power used -- only power for a short time when the carriage moves. I have the whole system on one Alpha pump with the Cross power coming off of the main pump power tap of the Viessmann boiler

HomerJSmith

Those two comments are nice to hear.

hot_rod

What is the total load? Always strikes me as odd seeing a wall of pumps all moving 1-2 gpm, each way off curve. When a single pump and zone valves could accomplish the same task.

mattmia2

hot_rod said:

What is the total load? Always strikes me as odd seeing a wall of pumps all moving 1-2 gpm, each way off curve. When a single pump and zone valves could accomplish the same task.

Manuals and books are great at showing piping diagrams for zoning with circulators and for zoning with zone valves but are not good at explaining why you'd use one or the other.

HomerJSmith

Cost, installation cost, and cost of operation. It works out a little cheaper with an ECM pump and Honeywell ZVs, than fixed pumps, flanges, and balancing valves.