What are the pro & cons of a 120V 6 element infrared heaters vs a 220 electric heater .?

At least two things going on in one question. First is the power issue.

Given that your basic US house receptacle is 15a/120v, 'can't use a 220v heater on it anyway. 220 circuits are more likely to be in use for major appliances, like a range or electric water heater, more likely to provide 30-50 amps, and again can't be used directly to power a 120v heater.

Related is the current needed by the heaters themselves, and the heat they can produce. A typical 120v portable electric heater is maxed at 1500 watts, giving you something around 4200 btus. A heater that can use 220 can produce lots more heat - if there's a proper circuit to power it, and the money to pay a higher electric bill.

If going for a 30a+ 220 unit, it's getting large enough to perhaps be called a furnace, and a primary heat source. In contrast, the 1500w 120 units are just for warming a cool room.

The second thing is the type of electric heater, like traditional resistance element, ceramic, and quartz-halogen, plus some "hybrid" types. I'm concerned you may be considering a "magic"/"Amish" quartz-halogen unit in a fancy box, basically over-hyped, misrepresented, and grossly overpriced at around $200-400. Still gonna be 1500w, and a little $30 1500w heater will heat just as well.

Best approach for most is to use a real furnace to heat the house just enough, then use a 120v portable electric to warm the room you're in a bit more.

Hey, I retail the things. 'Got about two dozen choices, from $25 to $300, including the "magic" boxes. If you get hyped elsewhere, I 'gotya covered, but I'd rather spend time with you to understand your needs and then make suggestions. My Christmas present? Somebody I sold a good thing to last year (heater, snow blower, etc.) who stops by to thank me, and has a relative who has a failed magic box they can't get fixed.

The advantage is you can spot heat areas you are using. The only way to save money is to use less heat. Electricity puts out 3.4 btu's per watt. Every watt the same, heat strip furnaces, IR, oil filled, ceramic, TV, vacuum cleaner, all the same heat. In fact it is such a constant that in some countries they convert natural gas billing into watts.

The disadvantage is using the 120v convenience outlets for heat is it is hard on the the electrical systems, I can't count the number of times I have been called to replace defective worn out receptacles or breakers and am told that they use temporary portable heaters as their primary heat source.

The only really relevant figure with heaters is the wattage. This indicates the heat output. Infra red heaters tend to be more comfortable as they heat objects (you) first rather than the air. But they are all equal in performance and running cost if the watts are the same.

I really need response from those who actually have used or are using this type of unit, and thanks for any and all responses other way and any comments about this type of heating system.