Air conditioning on a live aboard

[ranger58sb]

Originally Posted by Quadrille in JB

Why not discharge the condescent into the bilge?
My bilge (keel stub) always has ~1” of water in it and the condensate discharge is minimal.

Gak!

Our AC discharge is serious. One direct overboard, one to a shower sump.

And we like our dry bilge. If there's any moisture there, I want to know why -- right now!



-Chris

[redsky49]

Originally Posted by Quadrille in JB

Redsky49
Why not discharge the condescent into the bilge?

Originally Posted by Quadrille in JB

My bilge (keel stub) always has ~1” of water in it and the condensate discharge is minimal.

Condensate from a cooling coil, contrary to popular opinion, is not potable water. It is quite likely contaminated by trace heavy metals, bacteria, particulates, viruses, etc. While there is a process to distill fresh water from salt water using condensation, this ain't it. Proper practices with any HVAC unit should include the regular scheduled cleaning of the coil, condensate pan, etc., with an approved anti-microbial. Ensure that the HVAC unit is installed to ensure condensate drainage from the unit - minimize any standing water.


This is to ensure healthy conditions for the occupants of the vessel. But wait, there is more!


Allowing the accumulation of water in the bilge, particularly water that may contain pathogens, at the least will lead to odors, and could lead to far worse conditions. A well known boat broker in the Annapolis area cut his finger while cleaning something in a boat's bilge. The wound developed a staph infection that was initially resistant to antibiotics. There was some concern that this gentleman might lose his hand as a result. Fortunately they figured out a course of treatment. As more antibiotic resistant diseases arise (MRSA for example), these incidents could have far worse outcomes.



Legionella, the bacteria that leads to Legionaire's Disease, is one of those beasties that lurk in cooling systems. It is particularly nasty as it resists many common control methods such as were previously used in the basin of cooling towers (the likely source of the first well-known outbreak of Legionaire's Disease in Philadelphia, 1976). It resists both hot water (needing temps over 140 F to kill), and chlorine bleach ( susceptible only to hyper chlorination or "shock treatment"). And let's not get into Aspergillus and other molds that prosper in dark, warm and moist environments.


And if that is not enough, there is considerable evidence that wet bilges might contribute to hull blisters!


By the way, a cooling coil also dehumidifies, removing moisture from the air passing through the coil. The moisture condenses on the fins and tubes of the evaporator coil (based on coil temp, air conditions, etc.). When the water/condensate forms a drip, it dribbles down the coil and drops into the condensate pan. This could easily amount to several gallons each day with units of the size we are discussing. An unattended boat, with a non-functioning bilge pump, could quickly find water over the floorboards, (especially in French shallow-bilge boats), if condensate is discharged into the bilge!



I could point out several other concerns, but hopefully this will encourage everyone to maintain a dry bilge, a clean HVAC unit, and a happy, healthy and odor free boat.

[mabowers]

Originally Posted by redsky49

Condensate from a cooling coil, contrary to popular opinion, is not potable water. It is quite likely contaminated by trace heavy metals, bacteria, particulates, viruses, etc. While there is a process to distill fresh water from salt water using condensation, this ain't it. Proper practices with any HVAC unit should include the regular scheduled cleaning of the coil, condensate pan, etc., with an approved anti-microbial. Ensure that the HVAC unit is installed to ensure condensate drainage from the unit - minimize any standing water.


This is to ensure healthy conditions for the occupants of the vessel. But wait, there is more!


Allowing the accumulation of water in the bilge, particularly water that may contain pathogens, at the least will lead to odors, and could lead to far worse conditions. A well known boat broker in the Annapolis area cut his finger while cleaning something in a boat's bilge. The wound developed a staph infection that was initially resistant to antibiotics. There was some concern that this gentleman might lose his hand as a result. Fortunately they figured out a course of treatment. As more antibiotic resistant diseases arise (MRSA for example), these incidents could have far worse outcomes.



Legionella, the bacteria that leads to Legionaire's Disease, is one of those beasties that lurk in cooling systems. It is particularly nasty as it resists many common control methods such as were previously used in the basin of cooling towers (the likely source of the first well-known outbreak of Legionaire's Disease in Philadelphia, 1976). It resists both hot water (needing temps over 140 F to kill), and chlorine bleach ( susceptible only to hyper chlorination or "shock treatment"). And let's not get into Aspergillus and other molds that prosper in dark, warm and moist environments.


And if that is not enough, there is considerable evidence that wet bilges might contribute to hull blisters!


By the way, a cooling coil also dehumidifies, removing moisture from the air passing through the coil. The moisture condenses on the fins and tubes of the evaporator coil (based on coil temp, air conditions, etc.). When the water/condensate forms a drip, it dribbles down the coil and drops into the condensate pan. This could easily amount to several gallons each day with units of the size we are discussing. An unattended boat, with a non-functioning bilge pump, could quickly find water over the floorboards, (especially in French shallow-bilge boats), if condensate is discharged into the bilge!



I could point out several other concerns, but hopefully this will encourage everyone to maintain a dry bilge, a clean HVAC unit, and a happy, healthy and odor free boat.

I'm in process of installing a 16K Dometic. What about running condensate to a shower sump ?

[sailorboy1]

Toss some "Pan Tablets" into your AC pan a don't worry about Legionella. But regardless the blower coil is the place to worry about Legionella as that is the air blowing around that you going to breathe.

If you use the pan tablets that water going into the bilge is treated, it isn't going to smell. I long lost interest in the "dry bilge" idea!

[Alita49DS]

There are lots of threads here about a/c.

1. You have answered, in my view, correctly, your own question. Not to have a/c in a hot climate such as Florida is not an option. I would suggest ignoring all the diehards who write about fans and chutes.
2. You get what you pay for. A built in system will steal space but work well. A Mickey Mouse luggable unit will be, err, Mickey Mouse.
3. Therefore it will cost you.
4. However, you will not need a shore supply the diameter of your arm to run it. A 13 amp system on 240v or the US equivalent should do.
5. Conversely, a generator is probably not going to be able to run all the units at the same time. (We have 3 on 49ft/15m)

[ranger58sb]

Originally Posted by mabowers

What about running condensate to a shower sump ?

That's a very common solution.

-Chris

[170122]

We are cooling a 48 odyssey beneteau here in Dania FLORIDA with just 4200 BTU, it is amazing how a small unit can transform a humid boat into a dry an confortable one, 95 % of the time it is adequate but 7000 will be better, now the new copper fins are very efficient, they produce as much cooling as a much larger old equipment. The 4200 got heat and cool , the most impressive part of this system was the ability to run with a 28 lbs 1000 Honda generator at idle econo mode, 7 hours consuming just 3/4 gal of fuel.. the 7000 is the equivalent of an old 12000, copper evaporator fins are antimicrobial , they control your mold and avoid sick air problems. Depend how fast you want the vessel to be cooled, the size of your generator determine the size of the unit for your boat, for example a carry on Cruisair hatch unit was able to cool most sail boats with just 4500 BTUs!!

Originally Posted by Keithward

I’m in the process of buying a Pearson 422. Great boat excellent condition but no Air conditioning.
I will be keeping the boat in Florida and plan on cruising the gulf and Caribbean.
I am working from the boat . To not have air-conditioning is not an option.
it seems that for the 300 ft.² that I’m going to be living in I am at 25,000 BTUs or there about’s.
That seems incredible to me.
How big are the units in most 40 ft boats and thinking that Pearson 424s would be a perfect example but other 40 foot boats what do you have for air-conditioning and how effective is it and what are your issues. blessings thank you
Sweating in Florida

[john61ct]

For those with 100% dry bilges, I'm sure they would prefer to keep them that way.

For those accepting and dealing with wet ones, then yes sounds like adding another trickle of relatively clean fresh is NBD

[170122]

Amazing how bad air conditioning are designed for the marine industry, most 16000 BTU units only produce 10000.. on one of my boats a 40 ft I have 2 units, one 16000 and one 4200 BTU, 98% the last one keep our boat dry and cool, it run out of a 15a shore power, with the battery charger and 3 refrigerators. The 16000 is used only when we are all 6 on board, summer, generator, open door, 100F outside. The 4200 keep our boat confortable under way without running the generator, running on inverter with the engine alternator.