Adding bridge heat/ac?

First_Mate

First_Mate

New Member
Jul 22, 2010
125
Tennessee
Boat Info
2004 420DB
Engines
480CE's
Has anyone here added (after delivery) a bridge heat/ac system?

Ours didn't come with one and I'm thinking about taking the plunge. Biggest curiosities are:

16,000 BTU enough?
Will the existing 9KV Onan handle a third compressor?
Is the water difficult to plumb and get up to the bridge?
Where can you get the necessary parts to add one to the same standards as the $11K factory option? Cost?
 
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I'm interested in this also but I don't think my electrical system/generator is sufficient. I also understand that bridge AC systems don't cool the bridge, they just blow cool air on the captain which would be a marginal benefit for the dollars spent. Any input on this issue would be appreciated.

RB
 
I would go for the Cruisair 18000 btu model. It should be adequate on all but the hottest days. It will do more than enough when in heat mode in the winter. The 9 kw generator should be just enough to push all three a/c units on your boat at the same time. You may have a problem if you happen to be using all three units and you try to use your stove, microwave, water heater at the same time. But doing some quick calculations, I have seen more demand from smaller generator installations. The ductwork and electrical and plumbing is pretty easy to do since you have a bridge boat. I would say somebody with general diy knowledge should be able to handle this job. You will need a separate water pump to feed that new a/c unit which means a haul out to install a new through-hull. I would contact AA MABRU out of Florida. They are very knowledgeable and stock everything you need. Their prices are good too.

Cost?

a/c unit $3000.
water pump $450
thru hull and strainer and hardware and hose $600
registers and ductwork material $300
 
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I'm not even sure you would need another pump. I have 3 units on my boat a 7K, 9K, and 16K and they all run off of one pump. Also I can run all three at the same time on the generator (6.5 KW gas). As noted, it will run all three but in reality why would you need or want to when you're out on the water?

I would envision running the Salon unit and the Bridge unit at the same time.
 
I would PM Festivus44 if he doesn't chime in here. He installed bridge A/C-heat on his 44DB last winter.
 
Odyssey said:
I also understand that bridge AC systems don't cool the bridge, they just blow cool air on the captain which would be a marginal benefit for the dollars spent. Any input on this issue would be appreciated.

RB
Click to expand...

That's just not true... My bridge AC keeps the bridge at 72 degrees even on a 100 degree day...
 
I know this may be a cheap fix but I bought a stand up unit 12000 BTU it is a heater and air unit and does a good job just plug it in when needed only haft to run a exhaust hose it has a water pan but made a drain for it to go over board gusts sits in the corner behind one of the deck chairs.
I have A 8 kw westerbeke and two 10000 BTU and one 16000 BTU 220 units and it does fine
 
IMO, bridge air helps a lot. Last time I was on 480DB the difference was so big that all pannels were filled with moisture/condensation (I guess humidity level outside might have been high as well).

I happend to look at the most equiped and cleanest 420, which had custom bridge canvas with double lining. IMO, it makes a huge difference and is as close as you can get it to the hard top. So, this make a big difference when adding bridge air.

A stand up a/c-heat unit is an interesting idea. Now days they make very slick, conveniently small and yet powerful units.
 
You will need at least 32,000 BTUs to cool a bridge boat that has a hardtop. Anything smaller will not provide comfort in hot, humid conditions.
 
The hardtop is the key. Air conditioning a bridge with a dark fabric soft top is a tough proposition for a number of reasons. I have installed an 18,000 BTU unit and agree that it has a tough time keeping up on sunny days. It's not the heat so much (the unit does fine at night when it's hot out) but the sunlight flowing into an enclosed bridge makes for quite the greenhouse effect (the real kind, not the fake kind).

Think about it, if you left the bridge on a 420/44DB closed up on a hot sunny day, it would quickly get to about 120 degrees or more. The A/C is good to chop about 20-25 degrees off of that, which leaves you with... yep 95 - 100 degrees. I have managed it with sun shades that zip into the bridge panels (I have EZ2CY panels on the bridge), but they can't always be used. Like when driving!

I'm looking into getting a white vinyl top like they put on sportfish boats to help with the thermal loading. I'm also considering a zip-in "visor" for the top two feet of the front panels that I can use when driving.

All told, I'm still more comfortable up there enclosed in the A/C with the stereo on and no wind blowing my charts around and drowning out the VHF, and with the sun screen panels installed at night, they become privacy panels and the bridge becomes a nice "guest room".

Net net; I'm happy I did it, but I'm just trying to manage expectations.
 
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Also, to get the lines up to the bridge from the bilge, here is how I did it:

1. Remove the TV.
2. Remove the salon AC vent and register above the TV (while you're at it, check to see if the hole cut into the bottom of the register is actually the same size as the inbound duct... mine wasn't which was greatly reducing airflow to the salon A/C... but I digress)
3. Once that spot is open, you should be able to see a series of hoses/wires coming from the bilge area through the starboard side cockpit locker, up behind the TV unit and though a hole that goes from the salon to the hollow part of side of the bridge.
4. Decide where you are going to install the A/C unit, most likely in the starboard side cabinet of you have it. (Mine is installed in the U-shaped seating unit because I have a third helm seat. To do this I bought a low-profile unit [10 1/4" high] from Flagship Marine and I still had to raise the U-shaped unit 1")
5. Gain access to the hollow part of the starboard side of the bridge. "Gain access" being a euphemism for hacking large holes. I became quite comfy with the 4 1/2" hole saw during my install...
6. Run the lines from the bridge down to the salon.
7. From the salon, the lines should go aft through the starboard side cockpit locker and then down into the bilge. You will find that if you disassemble to starboard panels in that locker your life will be easier.
8. I protected all lines from beginning to end, both A/C and water, with hose tubing for chafe control. I don't know if that is required, but I did it. Various sized tubing can be purchased at cable organizer.com

Other thoughts/answers to your questions:

- I installed the A/C control panel on the starboard side of the arch.
for me, I was unable to run a gravity feed for the A/C condensate, there was no straight down run for me, so I used a Mermaid condensator which uses a venturi valve on the discharge side of the water flow to suck the water out of the condensate pan.
- I installed the third water outlet just forward of the salon A/C discharge on the starboard aft side. There is a pad of solid fiberglass back there where the A/C, generator and engine gas discharges are
- Upon recommendation of Flagship, I purchased a new pump to run all three A/Cs but I'm not sure I needed to since the new pump looked remarkably similar to the OEM pump. I now have a spare.
- The factory 2 position CruisAir pump relay is expandable to a third trigger by adding a simple board you can buy from any CruisAir dealer. So I have one relay that triggers the one pump if any of the three A/Cs come on. Remember to run a wire from the A/C unit to the relay. Given that the relay is behind the salon sofa, that run was something of a ***** too. Pull the icemaker out to get a better shot at it. You will need to do that (pull the icemaker) to get the main 10 gauge AC line to the panel anyway.
- I was able to install vents in the bridge arch by running twp 2" ducts up inside the arch.
- Running the AC units with the generator is not a problem. It is actually more of a problem with shore power. You may not have noticed, but you've got 30 amp main breakers on your shore power and 50 amp mains on the genny side. I have no problem running whatever I need with the genny on, but at the dock, you will need to manage the A/C hot water heater combination...

I'm sure there's more, that's all I've got right now.
 
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