Load calculation for an outdoor living remodel

[clemver]

Received drawings to bid on a large scale outdoor resi remodel. Haven't been to site yet. It's obvious to me they haven't considered the electrical load in anyway or got involved with an electrical engineer. I'm having trouble figuring out how to load calc all of this. Here's what theyre getting, this is all outdoors and detached from the dwelling:

• In ground pool. Not part of my scope, another electrician is handling this. Pretty sure equipment will be gas though.
• Detached shed. 2 lights and a few outlets for convenience
• Outdoor kitchen
  • 2 small appliance circuits
  • Gas grill
  • Gas cooktop
  • Fridge drawer
  • Ice maker
  • Mini fridge
• Hot tub
• Detached garage
  • Approx 12 lights
  • Approx 8 receps
  • 2 garage door openers
  • 1.5ton 18kw heat pump mini split
• (2) outdoor pergolas (this is where I get concerned over load)
  • Total of (8) 5200W 240V hardwired infrared electric heaters. Sized for continuous load, which is very likely they'll have all of these on full blast simultaneously gives me 216A.
  • (16) LED lights
  • (4) motorized screens

I'm assuming they have a regular 200A existing service. I want to say they'll need a 400A service just for the back yard. Obviously not looking for someone to calc this, just where I should start. Would the best approach be to calc each individual structure/component and then just add up the VAs? Doing it that way gives me a total VA of 71,943 with a calculated amperage of 299 not including the pool. Thank you.

 

[retirede]

My opinion:
Calculating everything individually and adding them will result in oversizing. You should confirm the pool loads. The main (non-house) loads to consider are the hot tub, mini split, and infrared heaters. The remaining outdoor and garage loads are small and diverse enough to ignore. If the house has gas heat, cooking, and hot water, I’d bet a 400 will handle everything.

 

[winnie]

• 1.5ton 18kw heat pump mini split

Double check this item.

In HVAC land, 1.5 tons means 18000 BTU/hr. A 1.5 ton heat pump will not need 18kW, even if it has 1.5 ton backup resistance heat. 18kW is about 61K BTU/hr, or about 5 tons. That is enough to heat my house on a -5 day....

The IR resistance heaters could very plausibly be on continuously if they are having a party in the winter ??. You need to add the continuous load factor for the circuits feeding these heaters, but I don't think need it when you are doing the total load calculation.

 

[WD40]

• (2) outdoor pergolas (this is where I get concerned over load)
  • Total of (8) 5200W 240V hardwired infrared electric heaters. Sized for continuous load, which is very

We did a restaurant/ bar with those for the outdoor eating, as the town would not allow gas heaters, I can't remember how many but I installed a new service, a dedicated panel-board, a contactor control panel that panel shop built just for the job, cost the bar owner a small fortune. They do run for all hours the patio is open. Owner said it was worth every penny. Next thing they will be blowing AC outside LOL.