A/C Retrofit
Posted by TangoLimaGolf@reddit | sailing | View on Reddit | 15 comments
Has anyone done their own AC/Heat install or recently paid for the yard to do it? I’m trying to figure a cost to retrofit a 16k system into our boat.
Outside of living my best life as a sailor I unfortunately have to work a real job as a Mechanical contractor so I have extensive plumbing and HVAC knowledge.
We are considering upgrading our current boat as well to one that has reverse cycle cooling installed from the factory. Either way this summer was brutal overnight at the dock and having heat would entice me to put the boat in the water much earlier than we normally do. Basically it’s a season extender for us.
DarkVoid42@reddit
get a mabru 12vdc unit. i have 2 on mine.
TangoLimaGolf@reddit (OP)
I’ll check it out!
tumbleweed314@reddit
I've done a lot of research and work on this, and finally got an install I'm very happy with. Go back through 20 years of forum posts, and the primary issue on sailboats is the startup current required when the unit clicks on. Usually this is overcome by putting heavy wiring or a capacitor in place. I went with a different solution, which was to get a continuously running aircon with an inverter that slowly ramps up the power to the compressor. The A/C stays on continuously, rather than switching on/off.
In practice, this has turned out very well. The overall power requirements are lower than a system that cycles on/off. On it's highest setting it draws about 1,100 watts continuously, and can cool the boat even on hot days in the tropics. At it's lowest setting it draws 450 watts, and keeps the interior cooler, and dryer, which is huge on an ocean crossing. Also, on it's lowest setting, combined with a Watt and Sea Hydrogenerator, I can run the A/C purely on sail power, without running a genset, which was my holy grail.
The difficult part of the installation was to find an appropriate self priming pump because I run the unit while sailing and it often loses prime in waves. Finding a brushless, self priming diaphragm pump was quite hard, and I eventually found one on Amazon that's meant for lawn sprinklers for $60.
The actual units that do this are the "Frigomar INVERTER BLDC SELF-CONTAINED UNIT" There's also one by Marbu, and Frigomar has a US version under a different brand (might be marineair, can't remember). These units also have a heat pump and can be used as a heater.
milesgloriosis@reddit
Which pump is it? GPM?
tumbleweed314@reddit
DC HOUSE 42-Series Brushless Motor Water Transfer Pump 110V 5.5GPM
I got the AC version so it would hook up to the aircon terminals, but a dc version would work too.
milesgloriosis@reddit
Thank you. I have 2 units on my boat but one common pump. It works fine until jellyfish plug the thru hull. And of course there is no redundancy. The self priming feature gives me more leeway on where I put the pump(s).
TangoLimaGolf@reddit (OP)
Awesome response. Thanks for the advice!
caeru1ean@reddit
I fell like we're on the verge of having some really great, efficient heat pump systems purpose built for the marine setting, they're just not quite there yet. I thought Marbu was supposed to be great but I've chatted with a few folks now that have had issues with them.
Holden_Coalfield@reddit
Do they have a DC equivalent?
Ancientways113@reddit
I have not but was toying with the idea when my system was malfunctioning. Seem to be plug and play, Provided you have raw water plumbing, wire runs and ductwork all in place. Heat and AC key at the peaks of season.
TangoLimaGolf@reddit (OP)
The only raw water plumbing I have is for the head to pump in. I might have to add a through hull.
Ancientways113@reddit
I would. You’ll need a vain pump on the raw water feed but otherwise i think the units are ready to go.
StarshipSausage@reddit
I am in the middle of a complete swap out. I went with 2 ctm units and micro touch thermostats. I have 2 units a 16,000 and 12,000 btu units. I recommend citimarine they have quick shipping and good support. The work is pretty easy, just time consuming. I would say about $2500 US.
TangoLimaGolf@reddit (OP)
Thanks!
NotThePoint@reddit
I have installed 3 marineaire systems. 2 of them on my current boat. It's not too difficult and summer or winter is always lovely inside.