How efficient is this Boiler setup

troyak

These are the boilers I have

https://www.ibcboiler.com/consumer/products/vx-series/vx-series-boilers/

hot_rod

the piping you have is what the manufacturers show. There are options that still accomplish what they ask for with hydraulic separation

I don’t think you are up for an entire repipe for the small gains you may get?

IMG_9336.png

LRCCBJ

Checking the mfr. specs…………the boiler can operate with a flow rate as low as 2 GPM. I would think the radiant zone would flow that amount in the worst case with the fixed output pumps.

hot_rod

6 to 1 turndown seems unusual in this day and age?

I wonder why they dont show direct piping schematics in the manual?

Their training lab has Caleffi separators on their piping🥰

LRCCBJ

@hot_rod

6 to 1 turndown seems unusual in this day and age?

I wonder why they dont show direct piping schematics in the manual?

Too conservative to risk 10:1

Too conservative to risk a possible high headloss emitter with an unknown pump, unknown pipe diameters, and unknown pipe lengths…………could result in less than 2 GPM and risk a high pressure release of water/steam.

Kaos

https://forum.heatinghelp.com/discussion/comment/1831245#Comment_1831245

There are a number of ways of skinning this feline. Simplest is don't have any small zones, old gravity feed conversion is the best for this.

The other option is to have a reference zone that always runs that is sized for the minimum flow rate the boiler needs. The rest of the zones can now be any size. As long as the reference zone is the coldest part of the house, it will always have more runtime than the rest so you still get good zoning control.

You can also set up all the zones valves to bypass some flow when off, so even if a small zone is calling there is enough flow through the rest to satisfy the boiler. Our typical setup where zones are either on or off is not needed except for something like a snow melt or garage, inside a house you don't need a zone to be truly off. If all zones receive some flow all the time, the return water temp will be much lower than an on/off setup which improves efficiency. As long as the bypass flow is reasonable, you still get decent zone temperature control.