Those of you with uninsulated aluminum boats have you found the D4 to put out enough heat for winter use? Looking to change out my current heat source for an espar and want to make sure I get enough heater this time. I have a 24' Boulton explorer, standard aluminum hardtop with vberth. By the sound of it the d4 should be plenty for my boat, but price is only $100 deference between the d4 and d5 kit. My salt boat is used 90% for winter use and my current heater puts out 7500btu's and 37 cfm's of heat and does little more than serve as a hand warmer. The downside of the d5 is obviously size and the battery drain is substantially greater than the 4, but for the minimal cost difference I'd hate to get the d4 and wish I'd have gone with the D5.
I've been on a few boats with Espars and they all put out plenty of heat even with the cabin door open, however they have also been insulated boats so its not an even comparison. I'd appreciate any feedback you guys can give before I make the order. Thank you