Mike Dolt Enterprises
Mike Dolt Enterprises
User: Open Neutral, Location: Inside the Beltway
Asked on: Wednesday, March 30, 2011 at 1:04 pm EDT
Answered on: Tuesday, May 14, 2024 at 3:29 am EDT
Question: A friend hit me up with a "Hey, you're an EE, you'd know..." query. And I don't...His employer, a non-profit, is buying a building, and there's a question as to how much service they will need; i.e. is the existing adequate to their needs.It's 4 stories, 12,000 ft^2, and will be offices. It's a nerdy organization, so everyone has a computer; but then doesn't everyone now? [A friend in Ohio built an ISP into a 1920-30's office building. There were two 15A outlet circuits per floor when they took over the space...]It's the Bay Area, so HVAC will be far less than in Houston or Miami.They might add an elevator; I'd think such would go on a separate metering per PG&E.Where do I go to start researching an estimate?
Sources for Research
US Department of Energy Building Energy Standards Guide
https://www.energy.gov/sites/prod/files/2014/02/f5/commercial_building_energy_standards_guide.pdf
ASHRAE Handbook - HVAC Applications
https://www.ashrae.org/technical-resources/bookstore/hvac-applications
IEEE Standards Association
https://standards.ieee.org/
PG&E's Energy Efficiency Guide
https://www.pge.com/en_US/residential/save-energy-money/tips/home-improvement/energy-efficiency-guide.page*
California Energy Commission (CEC)
https://www.energy.ca.gov/buildings
Steps for Estimating Service
1.
Determine Building Load
- Calculate the total wattage of equipment (computers, printers, lighting, etc.) per floor.- Multiply the wattage by the number of floors to get the total building load.2.
Consider HVAC and Elevator
- If adding an elevator, determine its power requirements and add them to the total load.- For HVAC, consult ASHRAE Handbook or CEC guidelines for typical energy consumption rates based on building type and climate zone.3.
Estimate Service Requirement
- Convert the total building load from watts to amps using the formula: Amps = Watts / Volts.- The voltage in the Bay Area is typically 120V or 240V.- Divide the total amps by the voltage to determine the service requirement in amps.4.
Check Existing Service
- Inspect the existing electrical service panel to determine its amperage rating.- If the existing service is inadequate, you may need to upgrade the panel or install a larger transformer.
Example Calculation
Assuming:- Total building load: 100,000 watts- HVAC consumption: 30,000 kWh per year (from CEC guidelines)- Elevator power: 15,000 watts-
Calculate Total Building Load
100,000 watts-
Convert to Amps
100,000 watts / 240 volts = 417 amps-
Estimate Service Requirement
417 amps-
Compare to Existing Service
If the existing service is rated for less than 417 amps, an upgrade will likely be required.
Note: This is just an estimate. A licensed electrician should be consulted for an accurate assessment and any necessary upgrades. Flag for review