Have you considered kerosene? (As used in cabin kerosene lamps.) Much less smelly than diesel. With non-smoke versions it's pretty human-friendly. I used to have a kerosene burner in a central heating system with radiators under the bunks. Excellent combination, kerosene and sailing boats.
The "Ge-Hå" heater is made in Sweden, by POD AB, thus not available in the US. The only noise is from the circulation pump for the water. Since it is a 12 V pump run on 6 V you have to put your ear next to it to hear it. It has 1.3 kW effect, and requires four 1-m radiators. With that onboard I could sail in the winter, no problem. I put it in the closet, doesn't need much space.
Here is a photo of the burner: POD