Indoor Space Heaters: what Claude and GPT would buy

Two AI models chose on their own, with no web access. Nobody tested these products: this is what each one says, and how to check it.

Claude and GPT choose the same brand, Vornado, but not the same product

In Home & Kitchen, Claude and GPT choose the same brand in 21 of 53 categories.

Claude Opus 5.5 · October 28, 2026

Vornado Vortex Heater MVH

A simple, well-built 1500 W fan heater that circulates warm air through a whole room instead of only blasting the spot in front of it, and it adds no combustion fumes or fuel handling.

Not for: People heating a garage, a large open space or a home during a power outage, and anyone who needs silent heat for sleeping.

GPT 6.1 Sol · November 10, 2026

Vornado VH200

Whole-room air circulation, straightforward controls, and tip-over and overheat protection make it a practical choice for supplemental heating.

Not for: Large, drafty rooms or bathrooms.

Which one fits you

off-grid or power-outage heat

Mr. Heater Buddy MH9BX

An indoor-rated portable propane heater with oxygen-depletion and tip-over shutoffs that runs without electricity.

Not for: Anyone heating a bedroom overnight or living above roughly 7,000 ft altitude.

permanent gas room heat

Rinnai EX direct-vent wall furnace (line)

A sealed direct-vent heater that draws combustion air from outside and exhausts it outside, so it adds no fumes or moisture to the room.

Not for: Renters and anyone without a gas line and an exterior wall for the vent.

Check before you buy

Fuel type. Use electric for bedrooms and occupied living spaces. Use combustion heaters only where they are rated for indoor use and the room has the ventilation they need. Fuel heaters produce carbon monoxide, water vapour and fumes. Electric heaters produce none.
Output vs room size. A 1500 W plug-in heater, which is about 5,100 BTU/h, suits roughly 150 sq ft as primary heat. Bigger spaces need fuel or hardwired heat. No plug-in heater on a standard 120 V circuit can exceed 1500 W, whatever the box claims.
Safety shutoffs. Electric heaters need tip-over and overheat protection plus a UL, ETL or CSA listing. Combustion heaters also need an oxygen depletion sensor (ODS). These shutoffs are what prevent fires and carbon monoxide incidents.
Thermostat. Prefer a real thermostat with a temperature setpoint over plain low/high switches. Cycling to hold a temperature saves energy and avoids overheating the room.

Where to find Vornado Vortex Heater MVH

Vornado
Target
Walmart

Shops seen in search results on November 5, 2026. A shop missing here may sell it too. Nothing was checked by a person.

Brands that matter

Vornado: Whole-room circulating fan heaters with good build quality.
De'Longhi: Oil-filled radiators, which give quiet, steady heat.
Lasko: Widely available, affordable ceramic heaters.
Mr. Heater: The reference brand for portable propane heaters.
Rinnai: Direct-vent gas wall furnaces.

What to avoid

Plugging an electric heater into an extension cord or power strip.
Running unvented combustion heaters while sleeping.
Uncertified heaters with no listing mark.
Wattage claims above 1500 W on a standard plug-in heater.

Questions

Do some electric heaters produce more heat per watt?

No. Every resistive electric heater turns 100% of its power into heat. Designs differ only in how they spread the heat and how quiet they are.

Do I need a CO alarm?

Yes, in any room where a kerosene, propane or gas heater runs.

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