Choosing a Backup Generator for Sarasota Homes With AC, Refrigeration, and Medical Needs | CoHarbor Electric

We did a job a while back in Sarasota Springs for a homeowner whose husband uses a CPAP machine every night, no exceptions. She wasn’t interested in a conversation about “typical” backup power. She wanted to know, specifically, that machine would keep running no matter what the storm did outside. Fair enough. That’s a very different sizing conversation than the one we have with someone who just wants the fridge cold and a few lights on.

That’s really the heart of this whole topic. Generator sizing isn’t a one-size-fits-all number pulled off a spec sheet. It’s math that starts with what actually has to keep running in your house, not what sounds impressive on a sales flyer.

Start With What Actually Can’t Go Down

Before talking kilowatts, we walk through what’s non-negotiable in the home. For most Sarasota households, that list includes some combination of:

• Central air conditioning, especially critical given how fast a closed-up house heats up here once the AC’s off
• Refrigeration — the fridge, and often a separate freezer for anyone who stocks up before storm season
• Medical equipment — oxygen concentrators, CPAP machines, home dialysis equipment, refrigerated medications
• Well pumps, for homes on private wells rather than municipal water
• Sump pumps, which matter more than people expect in low-lying parts of the county after heavy rain

Once we know what’s actually on that list, sizing stops being a guess.

Why AC Changes the Whole Calculation

Central air is the single biggest power draw in most homes, and it’s also usually the reason people end up wanting a bigger system than they originally planned. A portable generator can run a window unit or keep a few rooms tolerable, but it generally can’t start and run a full central AC compressor — that startup surge alone can exceed what a lot of portable units are rated for.

If keeping the whole house at a livable temperature during a multi-day outage matters to you — and here in Sarasota, in August, it usually does — that’s really the deciding factor that pushes people toward a whole-home standby system sized to handle the AC’s startup load, not just its running load.

Refrigeration Sounds Simple, But It Isn’t Always

Keeping a fridge running sounds like the easy part, and usually it is. But we’ve had homeowners near Indian Beach and Sapphire Shores who also run a second freezer in the garage, loaded up before storm season specifically so they’re not making grocery runs during a state of emergency. Every additional appliance is more load, and more load means the sizing conversation has to account for what’s actually plugged in, not just the obvious kitchen essentials.

Medical Equipment Isn’t Optional Load — It’s the Whole Point

This is the category where we push back hardest against undersizing. If there’s medical equipment in the house that someone genuinely depends on, that’s not a “nice to have” circuit. That’s the reason for the generator, full stop. We size around it first, then build the rest of the coverage around whatever capacity is left.

A few things worth knowing here: oxygen concentrators and CPAP machines draw relatively little power on their own, but they need continuous, stable power — no gaps while switching between grid and generator. That’s a transfer switch and sizing conversation, not a “plug it into whatever’s available” situation. If home dialysis equipment is involved, that conversation gets even more specific, and we’d rather over-plan for that than leave any margin for error.

Sizing the System Without Overbuying

Once we know the must-run list — AC, refrigeration, medical equipment, well or sump pumps if applicable — we run an actual load calculation rather than recommending a size based on square footage alone. Two homes near Ridgewood Park the same size can need very different generator capacity depending on whether one has central AC and a well pump and the other doesn’t.

Oversizing isn’t harmless, either. Bigger units cost more upfront, use more fuel, and sometimes need a bigger propane tank or gas line than the property really needs. The goal is matching capacity to what actually has to run, not buying the biggest unit available because “more is safer.”

What Homeowners Get Wrong Here

The most common mistake we see is homeowners deciding on unit size themselves, based on advertised wattage numbers, without accounting for AC startup surge or the cumulative draw of everything else in the house. The second most common mistake is treating medical equipment as an afterthought instead of the starting point for the whole sizing decision. Both of these are avoidable with an actual site visit and load calculation instead of an online generator size calculator that has no idea what’s actually plugged in at your house.

A Quick Word on Installation Itself

However the sizing shakes out, the system still needs a properly sized automatic transfer switch, and depending on your panel’s condition, sometimes panel work alongside it. All of this falls under NEC Article 702 for generator wiring, and it has to go through Sarasota County permitting and inspection — not something to shortcut, especially on a system you’re depending on for medical equipment.

Let’s Figure Out What Your Household Actually Needs to Keep Running

If AC, refrigeration, or medical equipment are part of the equation for your household, the sizing conversation deserves more than a generic recommendation. Coharbor Electric is a licensed and insured electrical contractor serving Sarasota homeowners from Sarasota Springs and Indian Beach/Sapphire Shores to Ridgewood Park and beyond. We’ll walk through exactly what has to stay running in your home, run a real load calculation, and help you choose a system sized for your actual needs — not a guess based on square footage alone. Reach out and we’ll get that assessment scheduled.