I’m installing a diesel heater and an alcohol stove. Sall good
Hi Smmahaffey, Love the Diesel Heat! What type, brand, size, boat are you heating? And where do you use the boat? (I ask this to know more about your climate/how cold it gets). If you're in a cold climate, good choice on a 'vented' Diesel heater, and especially so if you already have a diesel-engine boat; you can draw the fuel from the main tanks. (I know, that's not likely the case if you have a Parker, so whatever! Install a pony-tank!)
Try to properly size the Btu/h output of the heater to your specific needs. Even a small Diesel heater will put out a lot of heat. Most have multiple and/or variable settings. (In our 2520 pilothouse/cuddy we use a small portable propane heater, day-use-only, and only on the low setting as that is even too much heat most of the time. At night, and even when it's in the 20's outside, a 1500 Watt, 5120 Btu/h electric heater is more than adequate; even on a lower 800 Watt setting (2730 Btu/h), it is usually all that is needed. We had a vented, Espar Diesel heater on a previous boat. It was great, super-warm heat (about 130 degree supply-air temperature, vs the 95-105 degree supply-air temperature from our 16,000 Btu/h water-source, reverse-cycle Marine-Aire heating/AC system). Although that 95-105 degree heat would 'heat' the boat comfortably, the 95-105 degree 'heat' does not feel warm when you blow it on your 93-95 degree hands/body. (yes, 98.6 is our 'core' temperature; but the 93-95 is average body surface-temperature, is usually around what our hands are).
For giggles, try this experiment; 1) Take a deep breath. 2) Hold it for 20-30 seconds. 3) Put your mouth close to the back of your hand and SLOWLY blow that 98 degree air out of your lungs, onto the back of your hand. 4) It will feel warm. 5) Repeat steps one and two. 6) Put your mouth near the back of your hand and blow HARD, at high velocity! That same 98 degree air that felt warm a minute ago will now feel cool. But, it's the SAME temperature air!
You have just demonstrated 'wind-chill-factor' and also explained why we try to slow down the supply-air, on forced-air heating systems. The slower the air, the warmer it feels. (it's why some humans refer to 'heat-pump' heat, as 'cold-heat'!... whoops, didn't mean to get off subject...
Is your alcohol stove a 'pressurized' system or is it evaporative like an Origo Alcohol Stove? We had an Origo two-burner stove on our Albin back in the early 1980's. We really liked it, especially for it's safety factor, and ease of use, and lack of maintenance; just be aware it takes a LONG time to boil even a small pot of water. There's less Btu's produced with alcohol, and also be aware that burning alcohol produces carbon monoxide, and also produces tremendous amounts of moisture; best to use it in a ventilated space....