Beneteau 461 AC instalation

[John Zienda]

I am looking for any information about the AC installation on Ben 461. Specifically location of the cooling water intake sea-cock and pump, and supply air duct configuration in the main saloon. and forward cabin.

John Z.

 

[PeterBreit]

I have a 2000 Beneteau 461 with 2 AC/reversal heat pump units installed.
One is located beneath the main cabin starboard settee in front of the bulk head (Very easy access). The rear one is installed behind the quarter berth bulk head in the stern lazarette (quite difficult to get to for servicing, but the filters are reached from inside the rear cabin).
Air outlets are one in the main cabin on the starboard book shelf, one in the V-berth (forward cabin on the starboard locker) which is not very effective. I have a small fan mounted in front of the outlet to help with the cooling, not great for heating. The rear cabin has the air outlet on the rear buk head and the return beneath it. There is also an outlet in the pantry in the upper corner above the freezer. This works great.
There is only one cooling water pump for both units. Mounted in front of the engine compartment, beneath the steps with the through hull and strainer in front of it. Very easy access. The electrical switch control unit (2 switches) is mounted in the engine compartment on the starboard side wall. This turns on the pump automatically when the compressor starts up.
The digital AC/heat panels are on the side of locker cabinets in the main cabins and rear cabin. The circuit brakers are on the AC panel beneath the chart table (dumb location, difficult to reach).
I hope this helps. Peter Breit "BELVEDERE"

 

[Gunni]

Similar install on the 411. 12k BTU forward, 8k BTU aft. There has GOT to be a better way to mount/install that aft A/C unit that would allow for easier access to the stern compartment. Like maybe duct the return so that the access door is not blocked by the A/C unit. That would provide critical access to the rudder post assembly.

 

[PeterBreit]

I have 2 15k heatpumps. I wish Beneteau would have a 50amp line installed. the 30amp is pushing the limits when both compressors are running. I do have a dedicated circuit breaker and outlet. So the battery charger, outlets , ect. are separated.
In the B461 there is no conflict with the rudder post and return location. Filter change is easy from the cabin. otherwise servicing is done from the lazaret. Crawling around the rudder post....

 

[Gunni]

Yeah, two 15k A/C units require too much amperage - nearly 30 amps with no safety margin for overload due to plugs and connection resistance. Shoot for an installation requiring no more than 24 amps (less 20% of rated load). A 50 amp shore power feed doesn't fix the problem since you would have to be minding your other loads (HWheater, charger, outlets) if you ran off 50 amps. And where do you find a slip provisioned with both 50 amp service and 30 amp service? You pretty much have to manage your VAC power requirements to two 30A shore legs. One for house, one for A/C.

 

[John Zienda]

So this is what I am doing after getting some info from Beneteau and few other sources. I am installing two Marine Aire (www.marinaire.com) AC units with designated water intake sea-cocks and cooling pumps. One, 16,000 BTU, located beneath the main cabin starboard settee in front of the bulk head. I will have a 6" duct going to the angled register located on the starboard shelf over the settee. Right before the register, I will have a " T" connector taking a 5" duct to the forward cabin, with a 3" split for a small round register in the forward head. Have not decided yet about the size and the location of the supply register in the forward cabin. Also, I still have to find the location for the sea-cock and the cooling pump.

The second, 9,000 BTU unit, will be located in the starboard cockpit lazarette. Return air register on the starboard bulkhead in the rear cabin. I will run a 6" duct splitting into a 4" (going to the galley) and a 5" duct to going the rear bulkhead of the stern cabin with a 3" "T" to run 3" duct going to a small register in the rear head. I might install a cooling pump right behind the engine, unless I will find a better spot.

As for the shore power, I have installed a dedicated (second) 30A line with a circuit breaker panel located over the rear bulkhead shelf in the galley. This was an easy install from the starboard cockpit lazarette.

I will try to find all the supply air registers with dumpers, so i can control the flow between different zones. I will try to post some photos as the project progresses. My boat is in Kenosha, WI, being stored outdoors, so I have to wait for little warmer temps to keep on going. I would welcome any comments and suggestions.

 

[Gunni]

You should include a soft-start AC power relay for the units and the seawater pump. Keeps the power spikes managable when running both units and protects the pump by shutting it down if there is a problem. A single pump is all you need. It should be waterproof because it will be below the waterline in the bilge. March makes a tough unit. There are some specific ABYC install instructions that should be followed. Make sure you have easy access to your pump and strainer, priming the pump and strainer maintenance are frequent tasks.

 

[PeterBreit]

Se my earlier posting on the through-hull and pump location, also the electrical switches.
I considered a soft start switch to be able to run the AC with a smaller generator (2000 Honda). But then settled for a fixed installed NewGen 5500 generator in the cockpit locker. Some of the soft start switches don't work with older heat-pumps.
I never missed not having outlets in the 2 heads. Just leave the door open a bit and use a hatch mounted solar exhaust fan.
But you will need the largest duct you can install in the forward cabin. My outlet is above the starboard locker on the bulk head with a small fan located in front of it.
BTW.: Small 5" AC fans bought for $ 10.00 are strong and work great to distribute air throughout the cabins. They last about 2 years running almost continuously. Much more efficient then fixed build in ones for $ 80.00+ .