Any experience w/modular boiler system?

[wccfgene]

We are going to rennovate our facility and new mechanical equipment is on the list. We are going to replace 2 Kewanee steam boilers with new hot water boilers and the boss wants to go with a battery of modular throw-aways, the count is somewhere around 14 of 'em. Does this make any sense? Does the energy savings offset the maintenance that's going to be needed to keep them all operational? I understand that these things will run maybe 5 years or so before running into endless repairs. Any thoughts? Thanks, Gene

[slimwoodie]

i'd stay w/ commercial quality product....

maybe 4,or 5 condsensing boilers, of 1mm +

[HVAC Teacher]

I've had many satisfied customer with this strategy.

Multiple boilers provide backup if one fails, staged according to the load, energy savings.......

I also would go with quality units (many to choose from).

I would also use a control system that rotates the boilers for equal run time.

[wccfgene]

I've had many satisfied customer with this strategy.

Multiple boilers provide backup if one fails, staged according to the load, energy savings.......

I also would go with quality units (many to choose from).

I would also use a control system that rotates the boilers for equal run time.

Any suggestion on who makes a reliable unit? Rheem, Lochinvar? Thanks, Gene

[HVAC Teacher]

We've had real good luck with Burnham & Weil McClain (Cast iron sectionals)

[slimwoodie]

cast iron defeats the energy savings potential of multiple boilers

[slimwoodie]

AERCO BMS

Strongly recommended to maximize modular heating plant efficiency, AERCO’s Boiler Management System (BMS) offers remote access and control of multiple boiler installations and is compatible with Building Automation Systems (BAS) via Modbus open protocol or conventional analog signals.

The BMS is specially designed to leverage the operating efficiency of condensing gas-fired boilers capable of unmatched 20:1 and 14:1 unit turndown. It comes equipped with a Header Temperature Sensor and offers customers sequential or parallel application flexibility, constant or remote set point operation and provides 100% control of auxiliary boiler equipment while equalizing module runtime in the boiler plant.

BAS-equipped customers can be notified of faults throughout the boiler plant and can remotely examine up to 35 aspects of each boiler’s operation through a single connection point.

[HVAC Teacher]

I'm with ya slim, the Aercos are awsome. But it sounds like he wants to do it on the cheap. The CI's last forever & don't cost an arm & a leg. Too bad they are only 80%. But staging them would still save $$ compared to the present setup.

[slimwoodie]

i just converted a School from 27 c.i. Hydrotherms, to 3 Aerco's ...

expected savings are 50+ %

[heatingman]

This is a great trend that I've seen and done alot of. The biggest thing here is how the system is piped. PLEASE PLEASE PLEASE don't let the designer/ engineer get away w/o having flow controls, and a properly designed header.

Sounds like you may have a huge problem converting from steam to hot water though, as the radiator surface area will be inadequit at lower temps.

The University Of Chicago made that mistake a few years back. They ended up having to double the radiator surface area to account for the lower btu disipation.

[HydroK]

Hydrotherm has recently introduced a new line of boilers, the KN Series, that merges the modern technologies of condensing and modulation, with the proven reliable and long-lasting cast iron heat exchanger. These boilers have been independently tested to be ASME certifiable for 30+ years, with seasonal efficiencies near 98%. Your client might want to take a look at these, as they don't have the costly proprietary controls that make the Aercos so ridiculously expensive to maintain.