420DB – Bridge A/C and Heat Installation

[Alex F]

FWIW, my 40MY has a a 16,000BTU Bridge/Cockpit AC and a 9KW generator; never had any power management problems. The AC works reasonably well in a space I imagine is larger than the 420DB although it does have a hardtop and glass windshield. She does have 240V/50A power which is suppose is the major difference.

Thanks Al for chiming in. This kind of feedback gives me more comfort level about the project. According to the formulas 16K BTU unit should be good enough for the job, but considering the greenhouse affect of the bridge boat with soft top I understand that the larger size units would be a better fit.

Have you ever heard about Ocean Breeze brand, by any chance?

 

[Four Suns]

I think it's time to lock this thread.

 

[Alex F]

I think it's time to lock this thread.

You're posting this in a wrong thread. You wanted to lock LI Rendezvous thread.

Did you get my PMs? I didn't get your response.

 

[Four Suns]

I only respond to PM's from people with bridge AC.

 

[Alex F]

Well, now it all comes together, you can see why I'm busting my butt to get one.

I just got your PM, thanks.

 

[Hampton]

Alex, just checking in on this. I read all 11 pages. Very informative.

Pick a single unit. Keep it simple. I love the turbo. It's all about keeping the environment quiet with great air flow.

How many people sit next to a window in the sun in their living room at home and stay cool? I can't. I can't do that on the bridge either. What makes the bridge A/C nice is that in the morning, the air is crisp and cool for a nice breakfast. In the evening, same thing for a nice dinner. In the middle of the heat of the day, we sometimes open the glass and run the A/C because, as mentioned above, just having the cool air blow on you is very, very nice. In the winter, we can keep it warm under all circumstances - that is very, very nice.

I recommend the factory installation with one additional vent on the port side of the helm, next to the drink holders. My dealer removed one of the drink holder screws, rotated the drink holder around and re-mounted the second screw. Then, they installed the additional round vent where the original screw hole was. This was my wife's Christmas present last year (for starters). She loves it.

When we have guests over for brunch with the sun shining brightly, I pull the louvers off from the back of the unit where the air flows directly from the A/C toward the settee. This boosts the air toward the table and we all stay comfortable. The A/C is inevitably the conversation piece of the meal. If we are going to be cruising or just chillin' at the helm, I put a nerf ball inside the air duct near the settee to increase the airflow at the helm. For about $8,000 dealer money, it is an awesome addition.

Water flow: Our dealer installed a second through-hull, strainer, and 1000 gph pump. The water flow is huge. My thought on T-ing it off with a 1500 gph pump. Try it. As it is, my forward A/C water flow is usually just a moderate trickle and the forward A/C works just fine. Once primed, there will be no more head pressure to the bridge A/C than to the salon - the forward A/C outlet is the highest one, and that flow is therefore the least. I think my dealer may have installed a check valve to keep it primed. I'm not sure. That may benefit your install, but I am not an expert on the matter.

Electrics: I had to sign an agreement that I would not run the forward A/C and the cockpit A/C at the same time while operating on the genny. Doing so would void my generator warranty. We have never run both on the genny. We don't need to. The problem is not the 10 amps/unit, it's the startup/peak amperage. If by chance, both the cockpit and forward A/C's came on at the same time, the peak amperage would greatly exceed the 30 amp limit on the breaker panel. I don't know how this affects the genny, but I don't think it would be good - is it split into two electrical systems? Bottom line, when we run all three A/C's at the dock (only very, very, very hot sunny days), we make sure the cockpit A/C is set down to an in-achievably cool setting to keep it from cycling.

The turbo 16K BTU unit is a very nice, quiet, high flow unit. It will not cool your bridge like your living room on hot, sunny days. It will make your bridge very comfortable under all circumstances if you stay out of the sun. It will make your bridge very comfortable under 90% of conditions. You will use your bridge 10 times as much. It greatly increases the living space on your boat.

Don't over complicate the issue. Install a reasonable set and enjoy your boat.

 

[fc3]

So, when the next owner catches the boat on fire, is Alex liable for the damages and or loss of life because the new guy didn't know how not to overload the system?

Yes. Alex created a hazardous condition by building into the vessel excessive power consumption. I'm sure a court would find liability, especially if the plaintiff's attorney could find some evidence that he reasonably should have foreseen that problem. Even if the attorney can't find, say this thread, he can still go for negligence.

Greg's analogy does not hold up and is a false analogy. I wouldn't plug in ANY portable electric heaters either in my house or my boat for routine use. That would be stupid. It would also be very stupid of me not to consider power draw. If the builder of a house installs an excessive number of electric heaters, then he is at fault. They are built in. A bridge air conditioner is built in. The modifier has a responsibility to perform the modification in a manner that is safe and compliant with applicable codes. When I updated the kitchen, each appliance has a dedicated feed and there are multiple 20 amp circuit for outlets with no more than two duplex outlets per feed. Over speced, but safer because kitchen appliances draw a lot of power. A chef would have a very hard time overloading a circuit.

I already considered and discarded the idea of retrofitting air conditioning for my cockpit. It's not cost effective to add AC and upgrade the generator. But that is what is necessary to do the modification right. Drawing a high current over a long duration is not wise.

What secret society? Are you guys holding out on me?

 

[Alex F]

John,

Thanks a lot for your input. I'm glad you found the thread. You've provided a lot of good tips and most importantly your experience with the A/C up on the bridge. I always thought that if you're satisfied with the way your unit works being down South in FL region, then it's no brainer that I'll be very much happy with the same up here in the Northern region.

I have pretty good idea on the overall project, but one thing that remains puzzled is the condensation discharge from the drip pan. Do you know how the dealer routed yours? I thought that one of the options is to bring the line down to the salon's A/C unit and follow that line to the common drain sump box by the guest stateroom. Or T-off and tap in to the line from salon A/C to avoid running totally new line from throughout the whole salon. It's just gravity, no pressure. So, all it needs to do is just drain.

Thanks again,
Alex.

 

[Alex F]

Can someone comment on the difference in refrigerant NU22, 407 and R-410A. As I understand, Dometic units use R-410A. I just spoke to Ocean Breeze and they use NU22 and 407. They told me this is the latest and greatest refrigerant for recreational boating industry. They said that R-410A creates too high of a pressure.

 

[Greg]

Yes. Alex created a hazardous condition by building into the vessel excessive power consumption.

I still don't see how this is hazardous. I wonder if when SeaRay adds factory bridge air they also upgrade the shore power to 50A service. Seems if they don't that could be an issue while at the dock.

Greg's analogy does not hold up and is a false analogy. I wouldn't plug in ANY portable electric heaters either in my house or my boat for routine use. That would be stupid. It would also be very stupid of me not to consider power draw. If the builder of a house installs an excessive number of electric heaters, then he is at fault.

Why would he be at fault for building in an excessive number of electric heaters? I agree it is stupid, but as long as they don't exceed the rated load for the branch circuit they are on it is not unsafe or illegal.

They are built in. A bridge air conditioner is built in. The modifier has a responsibility to perform the modification in a manner that is safe and compliant with applicable codes. When I updated the kitchen, each appliance has a dedicated feed and there are multiple 20 amp circuit for outlets with no more than two duplex outlets per feed. Over speced, but safer because kitchen appliances draw a lot of power. A chef would have a very hard time overloading a circuit.

Here is something to think about. Go to your circuit panel in your house, add up the current ratings of all the individual branch circuits. Then compare that to the rating of the main breaker. So if you load each branch circuit to the maximum 'safe' load you have exceeded what the main can handle. Is that unsafe, or illegal?

I already considered and discarded the idea of retrofitting air conditioning for my cockpit. It's not cost effective to add AC and upgrade the generator. But that is what is necessary to do the modification right. Drawing a high current over a long duration is not wise.

I guess 'high current' is a relative term. I agree if the wiring, etc. is not rated for the current then that would not be wise.

What secret society? Are you guys holding out on me?

It's only for diesel bridge boats (with bridge air), sorry :grin:

 

[Alex F]

Greg, you're cracking me up.......:smt043

I got so much to comment, but I'll just stay quite so I don't offend anyone.

 

[Turtlesboat]

I never tripped my gen breaker, I run everything without thought. Even my awesome toaster oven. Mmmm toasted bagels.

 

[jg300da]

R410A and R407C are both HFC's and contain no free chlorine molecule (zero ozone depletion) which has been proven to be a contributor in destroying the earths ozone layer.

Both refrigerants are "blends" and as such require special attention when filling or recharging systems.

R407C's operating pressures closely mirror those of refrigerant R-22 (the refrigerant most household and commercial units have used in the past). BUT it cannot be used as a direct replacement in an existing R-22 system. This refrigerant requires no special fittings or guages to use.

R410A operates at much higher pressures and therefore requires specialized fittings and pressure gauges in order for these systems to be safely worked on.

 

[Hampton]

Drip: The drip is routed to keep a down-hill angle and leads down to the salon drip pan. It drips into that pan.

Off to the beach (if boat is back out of barn and into water, which I think it is).

 

[Alex F]

I never tripped my gen breaker, I run everything without thought. Even my awesome toaster oven. Mmmm toasted bagels.

Even your famous TNT lift doesn't trip the breakers?.........LOL

R410A and R407C are both HFC's and contain no free chlorine molecule (zero ozone depletion) which has been proven to be a contributor in destroying the earths ozone layer.

Both refrigerants are "blends" and as such require special attention when filling or recharging systems.

R407C's operating pressures closely mirror those of refrigerant R-22 (the refrigerant most household and commercial units have used in the past). BUT it cannot be used as a direct replacement in an existing R-22 system. This refrigerant requires no special fittings or guages to use.

R410A operates at much higher pressures and therefore requires specialized fittings and pressure gauges in order for these systems to be safely worked on.

Thank you!
Ocean Breeze told me that they can charge it with anything I want, they suggest NU22 or 407. Would you agree with their recommendation?

Drip: The drip is routed to keep a down-hill angle and leads down to the salon drip pan. It drips into that pan.

Off to the beach (if boat is back out of barn and into water, which I think it is).

That's sounds way simpler than I thought. Enjoy the beach, John.

 

[jg300da]

Stay away from NU-22. It's cooling capacity is less than 85% of R-22's or R407C.
To you that would mean considerably longer unit run time to do the same amount of cooling.

 

[fwebster]

Drip: The drip is routed to keep a down-hill angle and leads down to the salon drip pan. It drips into that pan.

Off to the beach (if boat is back out of barn and into water, which I think it is).

Everything is back in the water.....you are on the fish cleaning dock.

 

[Alex F]

Stay away from NU-22. It's cooling capacity is less than 85% of R-22's or R407C.
To you that would mean considerably longer unit run time to do the same amount of cooling.

So, I guess that leaves me with R407, unless I insist to go with R410.

 

[Alex F]

Update:

I spoke with March about their pumps and they're suggesting to go with this one, they said it's 1800GPH pump:



In regards to the 3-way splitter to feed all 3 units, they don't see an issue. As mentioned by few people here, they also said that all I'll need to do is to add basic valves to adjust the flow to make sure the furthest A/C (bridge in my case) will get enough pressure and the closest one doesn't use most of it. The valves will do the trick.

 

[douglee25]

Sounds like you got all the details now!

Doug