i see 2.5 gallon 120v ones on amazon. 12 amps, (15amp circuit). not on demand but if u place somewhere covered with no air inlet it shouldnt kick on often at all, can put on switch until an hour before u need. https://www.amazon.com/Ariston-Andris-120-Volt-Mini-Tank-Electric/dp/B07RT71RYH/ref=sr_1_2_sspa?keywords=point%2Bof%2Buse%2Bwater%2Bheater&qid=1649951903&sr=8-2-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFIOEEwNjkxWlkxWTImZW5jcnlwdGVkSWQ9QTA5MjcwNTIzMzI1MFRZQjZMSFdLJmVuY3J5cHRlZEFkSWQ9QTAxNTYyMTIyRUlWNjZSVFlJS1Y0JndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ&th=1