Capping Electric Peak Demand

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Old 11-15-13, 07:58 AM
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Capping Electric Peak Demand

My electric company severely penalizes peak demand over 10 kwh. We usually run in the 7 to 9 range but on really hot days we have briefly peaked at 12. Does anybody know of a device that would shut off the air conditioner at 9.9 kwh or otherwise stop us from accidentally exceeding 10 kwh on a hot day?

On Google I found this: Demand Limiting and this Peak Demand Control

I just don't know what the difference is between these devices and what kind would be best for my building...
 
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Old 11-15-13, 08:25 AM
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I just don't know what the difference is between these devices and what kind would be best for my building...
Is this a residential or commercial application?
 
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Old 11-15-13, 08:38 AM
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It is a commercial building.
 
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Old 11-15-13, 08:53 AM
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Shaving peak demand in commercial applications is a practice that can successfully lower electric bills, but if you only have one air conditioning unit, your options are severely limited. Generally, shaving peak demands is accomplished by shutting down some air handlers and rotating which air handlers operate when approaching a preset peak. It all depends on the comfort levels you must continue to maintain and priority levels in some of those areas. How many units do you have. Shaving peak demands is usually easier to do when you have a chiller and multiple air handlers. I have in the past worked extensively with Johnson Controls on shaving peak demands, but there are many companies that can do the same thing. I'd suggest that you contact some of these companies in your area and discuss with them what they can do for you. This is normally not a DIY project. FYI, here is some info on JCI.

Building Efficiency | Johnson Controls Inc.
 
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Old 11-15-13, 10:47 AM
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Capping Electric Peak Demand

Thanks Joe. We have one heating/AC unit on the roof and a bunch of ducts in the 10 rooms of our 2600 sq. ft. facility. So who would help with this? A company that installs controls? What would I google to find people in my area, or look for on angie's list?
 
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Old 11-15-13, 10:52 AM
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Do you have windows that open? If so I can see a future of tenants installing window ACs and unless they have separate electric metering I can see any saving being canceled out.
 
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Old 11-15-13, 12:35 PM
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Capping Electric Peak Demand

Not in most of the rooms, no.
 
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Old 11-15-13, 12:59 PM
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Like Joe.... I also work with energy management systems. If you only have one A/C unit your energy management options are limited.

If you only have limited over-peak times you may not be able to shave energy use to make it cost effective.
 
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Old 11-15-13, 01:04 PM
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I know one of the "tools" large commercial buildings use to increase efficiency at little cost is power factor correction. Is this effective for small commercial buildings? I don't know much about it so I'm just throwing it out there hoping someone will comment on it.
 
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Old 11-15-13, 04:46 PM
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I know one of the "tools" large commercial buildings use to increase efficiency at little cost is power factor correction.
Typically power factor correction will provide savings when a customer has a lot of motor loads as in, multiple air handlers, chilled water pumps, condenser water pumps, cooling tower fans, etc. For example, a building with a number of 25 HP to 100 HP motors would definitely see some savings. A smaller commercial building or a residence won't see any savings.
 
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Old 11-15-13, 05:00 PM
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We have one heating/AC unit on the roof and a bunch of ducts in the 10 rooms of our 2600 sq. ft. facility. So who would help with this? A company that installs controls? What would I google to find people in my area, or look for on angie's list?
You could just Google "Energy Management Systems", but I think your building is too small for a full blown system. Unless you can find a company that specializes in small buildings, you'll probably be better off making a priority list of list of capital projects such as replacing your current air-conditioning system with a new high effiency air-conditioning system, retrofitting fluorescent light fixtures to T5 lamps, installing occupancy sensors, installing a setback thermostat, adding insulation and possibly replacing the windows. If you check with your local power company, there may be incentives available to help reduce the cost of upgrades. Full blown energy management systems are better suited to building with electric bills running at least $20,000 - $40,000 a month.
 
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Old 11-15-13, 05:14 PM
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Can you describe your building in more detail? What is it used for? How old is it? Do you own or rent?
 
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