What are people's thoughts or experiences on the following: Design for a 500,000 sf hotel/condo with garage and retail. Preliminary expected load of around 3000kVA(no actual loads, using 6w/sf for basis of conversation). water-cooled Fan coil units in condos and hotel rooms. The majority of the loads are served at 208Y/120V. We're thinking of supplying the building with a 208Y/120V service. we feel as thought the 480Y/227V service would be overkill because we would need to buy large transformers(750kVA) to supply the condos with 208Y/120V and as we all know floor space is always an issue.
condo/hotel service
- Thread starter bwyllie
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- Lockport, IL
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- Semi-Retired Electrical Engineer
Re: condo/hotel service
I have been through that drill several times. Surprisingly, it is not an engineering question. It is initially an economics question, then it becomes a subjective decision. Here's what I mean.
With a 480 volt backbone, you will have much lower energy losses in the distribution system. You will also have lower material and labor costs for the smaller sized feeder conductors. You can also use 277 volt lighting in the hallways, and I think there is a cost savings there too.
With a 120/208 volt system, you don't need to buy extra transformers. You also don't need to set aside space for transformers and distribution panels, and there is a cost savings in terms of real estate.
It is arguable as to which system will require the greater amount of air conditioning, to offset the heat loses in either the transformers or the feeder cables.
Do the math both ways, and tell the owner which will cost more money. Be sure you have included maintenance costs. Then it becomes a subjective decision. Some owners just don't like the look or feel of a transformer room on each floor.
I have been through that drill several times. Surprisingly, it is not an engineering question. It is initially an economics question, then it becomes a subjective decision. Here's what I mean.
With a 480 volt backbone, you will have much lower energy losses in the distribution system. You will also have lower material and labor costs for the smaller sized feeder conductors. You can also use 277 volt lighting in the hallways, and I think there is a cost savings there too.
With a 120/208 volt system, you don't need to buy extra transformers. You also don't need to set aside space for transformers and distribution panels, and there is a cost savings in terms of real estate.
It is arguable as to which system will require the greater amount of air conditioning, to offset the heat loses in either the transformers or the feeder cables.
Do the math both ways, and tell the owner which will cost more money. Be sure you have included maintenance costs. Then it becomes a subjective decision. Some owners just don't like the look or feel of a transformer room on each floor.
Re: condo/hotel service
Make sure you can get properly sized HVAC chilers and pumps that will run on 208. If they are huge, you'll want 480 for them. Talk to the HVAC designer and see what he is going to need.
If the central plant is in a building seperate from your main building, you may be able to get a 480/277 service just for that building.
Make sure you can get properly sized HVAC chilers and pumps that will run on 208. If they are huge, you'll want 480 for them. Talk to the HVAC designer and see what he is going to need.
If the central plant is in a building seperate from your main building, you may be able to get a 480/277 service just for that building.
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