We live and sail in Alaska where some might say it never gets warm. Not ever
Over the years we''ve had a variety of heaters. The latest generation Espars are great. They are far more reliable than older ones. We have an Airtronic 4. It heats a well insulated 41'' boat easily at temperatures below freezing. It only draws .6 amps on low and 1.1 on medium. We have it setup to bring in 100% outside air (no recirc) and have woken up at below 0C temp''s to find no condendsation in the boat anywhere.
Downsides are initial expense, and they can be a maintenance issue. We''ve learned that European heaters like Espar despise American diesel
fuel. They run on it but it is not as refined as European diesel so the soot and sulfer plug them up. We have two
fuel tanks with the Espar drawing off the forward one. We put kerosene in that one except when fueling for a long trip. Costs more but it only burns .25 l/hour on medium so no big deal. Like most gear, good installation is key. Get proper
fuel line routing,
pump placement, low backpressure on the ducting etc. and you''ll like it.