420DB – Bridge A/C and Heat Installation

CAMELLA said:
And that is the whole discussion here, if I get a larger unit I would need a bigger pump with a larger ID hose, more amps which would require a bigger genset, RIGHT?
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Exactly, otherwise your boat will burst into flames and burn down to the waterline.
 
CAMELLA said:
And that is the whole discussion here, if I get a larger unit I would need a bigger pump with a larger ID hose, more amps which would require a bigger genset, RIGHT?
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Depends. If you already have 3 systems running, I would check to see if your gen could handle the extra pull.
 
Greg said:
I think the idea is to swap out the pump. i.e. remove the existing pump and replace it with the 1800 gph pump. Which leads me to mention this: Look at the relay that controls the pump and be sure it can handle the increased load of the larger pump.

I looked at the manual for that pump and it says it can _not_ self-prime, and can not run dry. Is your pump below the waterline? if not, you may want to reconsider the pump choice. If it doesn't prime, you may burn up the impeller. Even if it is below the waterline, you should see if they have something that can run dry. It would be a shame to burn up a pump because you forgot to open the seacock after cleaning the strainer.....
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Greg,

Thanks for taking the time and looking over things. Great point on the pump limitation "can _not_ self-prime, and can not run dry".

So, here's a quick update:
I checked my existing pump and it's a Cruisair.

I placed another call to March and had another discussion with tech support (sort of like a 2nd opinion). I guess, something we didn't know, March makes the pumps for Cruisair and Cruisare just puts their private label on the pump. So, the pumps we all have are the same in regards to the limitation "can _not_ self-prime, and can not run dry". I was told that the pump we have is very popular AC-5C-MD Magnetic Drive Pump (http://www.marchpump.com/ac-5c-md/) that can be bought in most marine stores like WM. So, I guess this is no longer a concern since there's no difference other than the new pump is much more powerful. And as you can imagine, the pump is below the waterline.

Then I asked the tech to comment on overall project. He said that there are different ways to do it and one of the major advantages for separate pump and strainer is to avoid dependency on one pump. If something goes wrong (clogged line or seastrainer, burned pump, etc.) my whole A/C system throughout the boat goes dead. However, it's still very common installation.

Mike (ididntdoit) - this also answers your questions. I told the tech that my preference is to minimize the overhead, drilling holes under the waterline unless I have to. I also told him that one of the reasons I wouldn't want to install new scoopstrainer with new seacock is b/c all the ones on the boat have "Barnegat Bay or Great South Bay" (whatever people like to call them) strainers to keep eelgrass, seagrass, jelly fish, etc. out. I prefer not to drill a hole for any of these extra components, b/c if I didn't than most likely I would have my strainer for the bridge clogged all the time (we have tons of eelgrass and jelly fish in our area). Then, the tech said that he had seen an installation where a seastrainer has multiple output allowing to use single seacock and strainer feeding multiple pumps. I asked what's the difference and advantage of adding an extra pump to the same line if the output is the same 1" hose. He replied that the scoop strainer should have 1 1/4" and it's good enough to supply water for multiple 1" lines. I thought that it's a great alternative vs. drilling the holes for new scoopstrainer and the BB strainer guard. So, this would mean that I could leave existing 5 series pump and just add the same 5 series for the bridge.

Then, I asked the tech to do a scenario comparison, two 5 series pumps vs. single 5.5 series (large 1800GPH pump). He said that 5.5 will win big time in regards to delivering pressure and volume to the units. It's just different level of pumps and it's rated to handle up to 60,000BTU A/C systems. The combination of my 2 existing 16K and the new 24K units makes it 56,000BTU total.

Then, I asked about the concern of having the "monster pump" to deliver all that pressure and possibly damage the A/C system's plumbing. He replied that the maximum pressure these pumps designed to produce was only 17PSI. He said that there's no harm to the systems.

Finally I asked, considering all of the variables what's his recommendation on overall approach? He said, do a single 5.5 series pump (http://www.marchpump.com/te-5-5c-md/), add the controlling valves to properly adjust the water supply to the furthest unit (the bridge) and you'll be fine. Keep existing 5 series pump in the tool box, so in the worst case scenario I can swap the pump and connect originally plumbed salon and fwd stateroom units.

I think this clarifies number of questions, especially for me.
 
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is
 
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Between this thread and the one I opened to get some more feedback on OB units (Ocean Breeze Marine A/Cs Quality - Good or Bad?), I think I've got enough comfort level in purchasing 22K BTU Ocean Breeze unit with electrical 2x2KW heating. It also looks like I'm pretty much set on the pump, so it's time to finalize the installation kit and go shopping.

Here's what my comparison matrix looks like (it's not 100% complete, but it has plenty of info for making a decision on the purchase):

Bridge_AC_Specs_Matrix.jpg
 
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A btu is a btu this is true. Looking at a sea ray sheet on my 560 sedan bridge it looks like my factory optional bridge AC is only 16,000 btu. 1.3 tons. my bridge is bigger than yours and mine dose a pretty good job.
 
Someone PLEASE take Alex' Excel away....


Let's see honey...you want to have a baby?

Well, let me fire up the computer and calculate all the variables...
What time of day is it?
What is the season of the year?
How many people had babies in the world last year?
How many babies were born in the United States?
When was the last time you had a pedicure?
Should we have sex or artificial insemnation?
Does my lift pump have enough lift or do I need some Viagra?
Which position is best for successful pregnancy?
How many times a day/week/month should one have sex to give the best chance of success?
What days do I have to work next week?

What do they call it? Paralysis by analysis...
 
Greg,

You beat me to it! I do believe that Alex originally questioned the quality of Ocean Breeeze because of it's 1 year warranty -VS- the others which were all at 2 years.
 
Yeah, but everyone seemed to be very happy with them, both the quality of there products and the customer service. So I wouldn't consider that a big negative at all.
 
unless it breaks during year two.
 
Lady Ashley SR560 said:
A btu is a btu this is true. Looking at a sea ray sheet on my 560 sedan bridge it looks like my factory optional bridge AC is only 16,000 btu. 1.3 tons. my bridge is bigger than yours and mine dose a pretty good job.
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I have to say that I'm really surprised that SR installed only 16K BTU unit. Even though your boat most likely has 240vac, but as you said BTU is a BTU. Other than your 16K unit draws less AMPs I don't see how it could perform better than an 16K turbo or 18K BTU unit SR installs on 420/44DBs. If I'm not mistaken 480DBs and 500DBs (there could be more) have 24K BTU units up on the bridge. I guess, the main difference is the white hardtop vs. dark color canvas top.

mistercomputerman said:
Someone PLEASE take Alex' Excel away....


Let's see honey...you want to have a baby?

Well, let me fire up the computer and calculate all the variables...
What time of day is it?
What is the season of the year?
How many people had babies in the world last year?
How many babies were born in the United States?
When was the last time you had a pedicure?
Should we have sex or artificial insemnation?
Does my lift pump have enough lift or do I need some Viagra?
Which position is best for successful pregnancy?
How many times a day/week/month should one have sex to give the best chance of success?
What days do I have to work next week?

What do they call it? Paralysis by analysis...
Click to expand...

Rick,

I don't man, there must be something going on there, but I see a connection when anytime I post a spreadsheet you immediately talk about sex. At least now I know not to say a word about Excel when we meet eye to eye.....:lol:. Is your "better half" working for Microsoft or specializing in Excel?


Greg said:
Nope, it's called being thorough....
Click to expand...

Exactly!!!

Greg said:
...Alex, didn't the Ocean Breeze unit have a lower warranty?
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That's what I asked them on the phone and referred to their warranty disclaimer on their site, but Joe (I think he's the owner) said that it's 2 years. In any event, I don't think it's a deal maker or breaker.

Turtlesboat said:
unless it breaks during year two.
Click to expand...

You got to be more optimistic. It's gonna work fine and much longer that 2 yrs, I have faith....:thumbsup:
 
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I own a boat, optimism is no longer in my vocabulary.
 
So when do we get to vote on where to drill the hole in the side of your boat for the discharge hose?
 
Alex,

I wouldn't read much into the fact the the 560DB has only a 16K bridge air unit. Bridge and cockpit a/c is a relatively new "must have". Prior to the mid 2000's it seems only the bigger boats had them and the size of the units were only what would fit within the standard generator capacity. Later models have more energy efficient electrical components so there is more "room" in the generator capacity for bridge/cockpit air. Sea Ray did/does offer enough bridge or cockpit air to hang meat, if you order the boat with an optional up-sized generator and that, plus the added cost of the A/C units and plumbing was way more than any dealer would order on an inventory boat.
 
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