Design Load for Doctor's Ofiices

[stevedye]

Hello, This is Steve Dye from Beckley, WV. My firm is building a 5,627 sq. ft. doctor's office building. 2000 sq. ft. will be leased out to another doctor. 3,627 sq. ft. will be used by my client. We are assuming a 400 amp panel for the larger side and 200 amp for the lease space, all single phase.. The space has no special equipment such as x-ray equipment. There will be standard receptacles, lighting and HVAC and parking lot lights. The local electrical company wants us to supply the estimated demand load for our project. Can you give me some guidelines using historical guidelines for similar projects? What other useful info. could you pass on to us? We are in an office park development and the developer will run power up to a transformer at our property line. The electric company needs to know the demand load. What should we tell them?

 

[Dennis Alwon]

If you have an electrical contractor involved then they can do a load calculation but you need more info then what you presented. The power company around here also wants locked rotor amps of the a/c units.

 

[petersonra]

Hello, This is Steve Dye from Beckley, WV. My firm is building a 5,627 sq. ft. doctor's office building. 2000 sq. ft. will be leased out to another doctor. 3,627 sq. ft. will be used by my client. We are assuming a 400 amp panel for the larger side and 200 amp for the lease space, all single phase.. The space has no special equipment such as x-ray equipment. There will be standard receptacles, lighting and HVAC and parking lot lights. The local electrical company wants us to supply the estimated demand load for our project. Can you give me some guidelines using historical guidelines for similar projects? What other useful info. could you pass on to us? We are in an office park development and the developer will run power up to a transformer at our property line. The electric company needs to know the demand load. What should we tell them?

the code has procedures for making these calculations. see article 220. the procedures are not especially complicated but they are not all that obvious either. best to hire someone to do them that has some experience.

this is no real different than similar calculations that would be made for any other type of building.

 

[Ingenieur]

as others have said EC's have experience doing the utility load sheets
you have 4 primary load types:
lighting, easily calculated
HVAC, worst case either heating or cooling or both if dehumidifying
special equipment, must be supplied by owner, usually easily calculated once you get the data, not so easy (washing machines, dryers, stoves/ovens, water heater,medical equipment, etc.)
receptacles loads, kind of a WAG, I use the residential load of 180 VA each, never been bitten

as far as demand
100% for lighting and HVAC
75% for the balance

just eyeballing it the 400 and 200 should be plenty
VA/sq ft for office at 80% loading is 21, a little high
for lease space 19

you can find similar for most utilities

http://interchange.puc.state.tx.us/WebApp/Interchange/Documents/40627_44_742994.PDF

second page, item 14, clinics, 12.8 VA/sqft

 

[stevedye]

If you have an electrical contractor involved then they can do a load calculation but you need more info then what you presented. The power company around here also wants locked rotor amps of the a/c units.

Thank You Dennis.

 

[stevedye]

as others have said EC's have experience doing the utility load sheets
you have 4 primary load types:
lighting, easily calculated
HVAC, worst case either heating or cooling or both if dehumidifying
special equipment, must be supplied by owner, usually easily calculated once you get the data, not so easy (washing machines, dryers, stoves/ovens, water heater,medical equipment, etc.)
receptacles loads, kind of a WAG, I use the residential load of 180 VA each, never been bitten

as far as demand
100% for lighting and HVAC
75% for the balance

just eyeballing it the 400 and 200 should be plenty
VA/sq ft for office at 80% loading is 21, a little high
for lease space 19

you can find similar for most utilities

http://interchange.puc.state.tx.us/WebApp/Interchange/Documents/40627_44_742994.PDF

second page, item 14, clinics, 12.8 VA/sqft

Thank You Sir.