Factory Energy Management

I am working on a job where the specification calls for a "factory energy management system" to control the Heating, Ventilaion, Air Conditioning, air compressor, and lighting in a 200000 sq-ft building. What is is the best way to do this job? All suggestions are deeply appreciated.
Lancie

Basically, how long is a piece of string? There should be some requirements documented in the spec as to what they want.

Be careful if there is not. YOU will get caught with how long is a piece of string.

Suggest you ask for written details on what is required. If they do no come up with written detail, run the other way.

I agree with Bob, coming from this area. The sticky bit is when is asked "to control all new and existing equip" and there is no points list attached.

The two major players for open protocol are Bacnet and Lon. eg Honywell, Invensys, Johnson, Seimens, Delta, Alerton and so on.

Make damned sure that your sub-station has a healthy margin for growth (20% minimum... of course, this is subject to "expected growth" in the near future, 5-10 years).

Then, it's simply a matter of matching supply with demand and managing load distribution (snort! ...easy to say, huh?) on the various panels.

If it hasn't already been done, then you need to have an energy audit done (have this done on a panel basis, and on a time basis. Then examine the loads in terms of expectations).

You'll need to know the demands as they exist and the capacity of the panels that are providing for those demands. Always try to have at least 20% available capacity in all panels. You'll also be responsible for cost of power... so keep the Power-Factor in mind.

You also need to be aware of the voltages and phase-counts that are available. It does no good at all to have 60% availability in a 120V/220V (2-Phase) panel when what you need is 220V 3-Phase.

Basically, you need a Supply/Load Map. Make those maps "living documents". As changes are made, motors added, panels upgraded, update the map and plan accordingly.

The two major players for open protocol are Bacnet and Lon. eg Honywell, Invensys, Johnson, Seimens, Delta, Alerton and so on.

Click to expand...

Have used BACnet interface from Citect SCADA system to Alerton on TCP/IP before. It is very slow. Do not know if there is a BACnet to Ethernet converter available for PLCs.

Have just finished a job into a Cummins PCC generator controller system with a LON/Modbus RTU converter into an Omron CJ1M PLC. The interface unit was supplied by Cummins and I believe it was an arm and a leg to buy from Cummins USA. Worked fine though.

They are looking for a system such as the other responders have indicated from Siemens, Honeywell, Johnson Controls etc... The requirements should have been outlined in a specification Division 15 Mechanical/HVAC (typically) in addition to what is on the drawings, unless the design is using the new CSI standards for specifications then there is a separate section defining what is required. Like the other responders have said, be careful, what does the "Energy Management System" do? Monitor only, supervisory control, are you using an HMI software? What are all the systems you are monitoring or controlling? HVAC, Fire Protection, Access Control, power distribution (power main, distribution, panel boards). The pieces / parts are all there to do it. You can use most HMIs with BACnet drivers and many manufacturers support the protocol. I have done a system using BACnet over ethernet with various converters to connect Citect HMI to power distribution using Lithonia products, HVAC using Alerton controllers, access control, fire protection with Simplex. We had a decent definition of what was being monitored and/or controlled for each of these systems.

Good luck

The complete energy management specification says: "Provide a factory energy management system to control the heating, ventilaion, air conditioning, air compressor, and lighting."

There are drawings detailing the HVAC, the 200 hp air compressor, and the light fixtures. I beleive that they want something to minimize the power bill, using the listed components. This is a spec from a Japanese company building a plant in the US. The entire building spec is only about 10 pages. They believe in letting the general contractor figure out what is needed, but holding him responsible for how it works. Questions from bidders are definitely NOT encouraged.

In this type of specification, no details are given. Only the desired results are listed. The rest is up to the bidder. I am thinking that, for a complete energy management system, I need also to add a power factor controller (variable capacitor bank). What do you think?

The air conditioning (heat source is gas) is a big energy load for a building this size, so the Alerton system sounds like a possibility. I could always install a PLC and run remote I/O to each listed power user. Another possibility is to add Devicenet to all units and network everything together back to the communications room.

I have read some negative comments about BACNET and BACTALK. Does anyone have any other comments about those HVAC control systems?

Lancie1,

One thing to think about is that HVAC control you did for that church way back when..If I remember correctly it was about staging motor starts.

Anyway, vague specs like these really scare me. The owners objective is to go cheap on the arch/eng costs of producing the specs. The problem is the bidders will be all over the place, and the'll be compairing apples to oranges when it comes time for evaluation and selection. I bid on a job like this ONCE. The job was then re-bid with chosen specs provided by the 1st bid process. After checking out our section (14000) it was obivious they had chosen all the least expensive alternatives. I didnt bother with it from there. The job turned out to be a total mess...

Is this a job that you have already been awarded? What does your companies quote to the customer say and how much monies was allocated to do it?

Mike,

Yes, Mike, I remember the church heating program. It apparently was satisfactory to the church members. They sent me a charitable contribution credit, which was nice at tax-return time.

No, we have not been awarded this contract. We are still in the bid stage, although the preliminary bid meeting has been held and only the bidders that showed up are now elgible.

I get the impression that cost in this case is not the main concern. I think that the specs are vague because the owners maybe prefer that a Japanese company get the bid. They probably have some inside information back in the home country. That makes it tough on us natives.

"Specifications: how detailed should they be?" is a topic for a whole other discussion. I have seen specs that described everything, including the kitchen sink. They try to cover every possibility, and wind up describing things that are not even part of the contract. Then a bidder has to wade through and separate the wheat from the chaff.

On the other hand is the performance-type that just describes the results and leaves the details up to the bidder.

There are problems with both types. The ideal must be somewhere in the center.

Being diretly involved in the industrial & commercial construction busniess, we're starting to see these all the time.

Most of the time it's the owners way of finding out how much it will cost, (job may not be actually intended or in the study phase), and/or not having to pay a consultant of some type to do the study. They pick just a few contractors to get propoals from; then if the cost meets the budget and the jobs a go, then they gather all the least expensive proposals into a comprehensive spec, and put it out for bids again. When the final version hits the Dodge Reports it'll be a feeding frenzy, and you'll have no better real chance of getting the award then the next guy who didnt get suckered into the 1st round of proposals.

Mike,

So it could be a way of getting the contractors to "write" the specifications? I had not thought of that; it is pretty underhanded. It may not work in our case. We are going to give them a one-page bid, with the cost and terms.

Lancie1 said:

So it could be a way of getting the contractors to "write" the specifications? I had not thought of that; it is pretty underhanded. It may not work in our case. We are going to give them a one-page bid, with the cost and terms.

Click to expand...

It sure seems that way to me.... Your "bid" would likely be rejected if it didnt include a specific "proposal" outlining a complete spec of what your proposing to provide.

Consultants (eng/arch) cost a bundle. For a project like this maybe a 1/2 million or so. The owner dosnt want to spend that because he's not yet sure if he's actually going do the project.

Mike,

The owners did include the one-page bid form in the package (one of the 10 pages). That is all they will accept, so there is no place for any specifications. In this case we ARE those expensive "Consultants (eng/arch)", except it seems that we usually don't wind up with much of the money! Check your PMs!

Under those circumstances, My second guess is their just doing a cost study. Or is it a Design/Build project on the fast track? We just finished with one of thoes...WOW! what a head rush... Change this.. NO! Change that...What Change that and this!....Now all we gotta do is get paid for all thoes changes!!