Trying to find a little balance in all things. First, goals: 1. Provide dockside heat at the boat as well as at anchor. At anchor would be less frequent, but that could change ina few years. 2. Provide power source to recharge batteries while at anchor. I have a Heart Interface 100 amp charger/inverter that would have to be powered. Immediate thoughts are to put in a 2.2kw genset (Yanmar for example) that should run the charger. Second thoughts are to put in a 9,000 btu ac reverse cycle or electric heat system from Mermaid or other. Concerns: I'm trying to keep the genset weight down to a reasonable level. This is going in a Hunter 356 and the 3kw units are getting over 200 lbs. The 2.2kw units are quite a bit less weight. It looks like the 2.2ks unit would run the 9000btu ac/heat units. I know this might be somewhat small for the boat, but I'm not looking to live on it either. Just want to take off a morning chill or cool the evening down a bit when we have the unusual hot spell. Reverse cycle or electric heat? Any thoughts or help are appreciated. Dan Jonas (S/V Feije II)
- Status
356 Install...
At some point, I will also be doing what you are thinking of. First of all, I would go with the larger reverse cycle AC/Heat unit, probably around the 16000 BTU size. It fits the cabin size better. An alternate might be to put two of the 9000 BTU units in the boat, and run just the single when needed, say for the aft cabin. Second, I already have a 2500 Watt inverter, and it should be able to handle the startup current of a unit, (or the two 9000 BTUs, as long as the startup was staggered). My thought was to be able to run a gen set to bring the cabin temp down (or up with the heat) after the end of a day, and then be able to use the inverter to maintain the temp through the night. Once the temp reaches the level set, maintaining it should not draw that much off the house batteries. You could even start at a lower level (cooler) and then bring up the thermostat a bit to give it a little help. I spoke with the people that make the inverter, and they say that the unit can take 4000 watts for a short period (startups), and the AC people say they haven't heard of anyone using an inverter, but it should work becasue thier startup is not that high. The draw is not continous, and you would certainly have to plan to have a full charge in the evening, and then cahrge up again in the morning, but for comforts sake, it sounds OK to me. The 2.2K genset will work only if it can handle the startup current. Getting a more expensive inverter that can sync with the genset might also be an answer. Kind of a different set up, where you're charging the batteries with the genset AC, pulling DC from the batteries to make AC with the inverter, and using both the genset and inverter to startup the AC unit. Once running, you can shut off either the genset or the inverter. What ever you end up with, everything should match as a system. As long as everything works and achieves the end goal, it's a success, right? Keep in touch and let me know what you end up with. Steve sestyles@yahoo.com
At some point, I will also be doing what you are thinking of. First of all, I would go with the larger reverse cycle AC/Heat unit, probably around the 16000 BTU size. It fits the cabin size better. An alternate might be to put two of the 9000 BTU units in the boat, and run just the single when needed, say for the aft cabin. Second, I already have a 2500 Watt inverter, and it should be able to handle the startup current of a unit, (or the two 9000 BTUs, as long as the startup was staggered). My thought was to be able to run a gen set to bring the cabin temp down (or up with the heat) after the end of a day, and then be able to use the inverter to maintain the temp through the night. Once the temp reaches the level set, maintaining it should not draw that much off the house batteries. You could even start at a lower level (cooler) and then bring up the thermostat a bit to give it a little help. I spoke with the people that make the inverter, and they say that the unit can take 4000 watts for a short period (startups), and the AC people say they haven't heard of anyone using an inverter, but it should work becasue thier startup is not that high. The draw is not continous, and you would certainly have to plan to have a full charge in the evening, and then cahrge up again in the morning, but for comforts sake, it sounds OK to me. The 2.2K genset will work only if it can handle the startup current. Getting a more expensive inverter that can sync with the genset might also be an answer. Kind of a different set up, where you're charging the batteries with the genset AC, pulling DC from the batteries to make AC with the inverter, and using both the genset and inverter to startup the AC unit. Once running, you can shut off either the genset or the inverter. What ever you end up with, everything should match as a system. As long as everything works and achieves the end goal, it's a success, right? Keep in touch and let me know what you end up with. Steve sestyles@yahoo.com
Reverse cycle should work.
Assuming the Alameda is the one in California that is. On Lake Erie my Mermaid 12K unit keeps us quite toasty until the water temp falls below about 45 degrees. The boat is 37' but has less interior volume than yours. I think one 16K unit would be ideal for an H356. I can run mine with my Honda 2000W generator but only because I also have a Heart 2000W inverter/charger. The inverter handles the 15+ amp surge at startup. I think you would need the same for a 2200 generator. I have always thought that I would go with diesel heat if I needed more. I do not have, nor want, propane. It would be nice to just tap off that 50 gallon diesel tank. Regarding Steve's idea of running off the inverter I don't think it will work. Maybe one 9K unit but certainly not 12K or 16K. Even if it would start it would eat the batteries. Our boats are so poorly insulated that you would have to really crank the thermostat up/down to the point it might as well be off.
Assuming the Alameda is the one in California that is. On Lake Erie my Mermaid 12K unit keeps us quite toasty until the water temp falls below about 45 degrees. The boat is 37' but has less interior volume than yours. I think one 16K unit would be ideal for an H356. I can run mine with my Honda 2000W generator but only because I also have a Heart 2000W inverter/charger. The inverter handles the 15+ amp surge at startup. I think you would need the same for a 2200 generator. I have always thought that I would go with diesel heat if I needed more. I do not have, nor want, propane. It would be nice to just tap off that 50 gallon diesel tank. Regarding Steve's idea of running off the inverter I don't think it will work. Maybe one 9K unit but certainly not 12K or 16K. Even if it would start it would eat the batteries. Our boats are so poorly insulated that you would have to really crank the thermostat up/down to the point it might as well be off.
Inverter/Charger Surge
Ed, I have the Heart Inverter/Charger. I'll have to look at how it is hooked into the air conditioner side of the panel. You say it handles the start-up surge and you are running the 12k btu unit ok. That's helpful information. I wonder if would bridge the start-up load for a 16k Unit with a 2200 watt genset? Also, our water temperatures run in the mid 50's or more pretty consistently. As much as I would like to use the 16K unit, I'm a little concerned about the start-up. If I can only start it on shore power, than the investment was not planned out as well as I would hope. Also, how do you like the reverse cycle heat vs. an electric strip model? I agree that running the ac off the batteries is a non starter. We are talking 8 amps minimum at 120, which would take my 400 amp bank down to recharge in just over 2 hours. Not the kind of cycle load I want to waste on them. Dan Jonas
Ed, I have the Heart Inverter/Charger. I'll have to look at how it is hooked into the air conditioner side of the panel. You say it handles the start-up surge and you are running the 12k btu unit ok. That's helpful information. I wonder if would bridge the start-up load for a 16k Unit with a 2200 watt genset? Also, our water temperatures run in the mid 50's or more pretty consistently. As much as I would like to use the 16K unit, I'm a little concerned about the start-up. If I can only start it on shore power, than the investment was not planned out as well as I would hope. Also, how do you like the reverse cycle heat vs. an electric strip model? I agree that running the ac off the batteries is a non starter. We are talking 8 amps minimum at 120, which would take my 400 amp bank down to recharge in just over 2 hours. Not the kind of cycle load I want to waste on them. Dan Jonas
- Status