Air Conditioner Thru Hull Questions?

1970Columbia34 · #1 01-14-2007

As some or most of you know we are installing a Air Conditioning unit in our boat and I have found a nice low spot on in the bilge for the water intake, but uts near the knot meter through hull. Is there any reason or rule of a distance they need to be apart.

Also I need to run and 4" duct to the v-berth can I drill the 4" hole through a bulk head? and if I do, do I need to support the hole buy doing backing plates on each side of the bulk head?

Also I have 2 options for the condensation from the unit to drain into the bilge or pump it out. I would like to pump it out is there a special pump for that? or just another bilge pump? And where do I exit the water from this pump another thru hull above waterline? Thanks

camaraderie · #2 01-14-2007

Columbia...I would put them about 6 inches apart just for hull integrity insurance. No problem on cutting a 4" hole and no backing plate required unless you are doing it at the very bottom of the bulkhead.
A regular small bilge pump will work and you will need an above the waterline through hull for it unless you can T it in to another overboard line like from a sink. Don't T your existing bilge pump line. Be sure to put a loop in any new line you run to prevent siphoning when heeling. All in all it is a LOT simpler to just run the drain to the bilge.

PBzeer · #3 01-14-2007

On my Cruisair, I have a above waterline thru-hull for the A/C discharge. I also have a very hefty pump, but it runs on 115V, not DC power. Your power source is the determining factor as to the pump. My raw water is T-eed off the top of my cockpit drain (which for some reason is on a thru-hull on the bottom of the boat).

As far as I know, if you are running your pump on AC power, all the pumps are designed to be below the waterline (not self-priming).

1970Columbia34 · #4 01-24-2007

Does the raw water pump for the Air Condition unit have to be near the unit or can i put it back buy our motor, its has the easiest access for installing the thru hull and easy access for the future, but i would be pumping the water about 15'. thanks.

Scott

Zanshin · #5 01-24-2007

My A/C intakes are far from the units - you just need to make sure your pumps are up to the job.

camaraderie · #6 01-24-2007

You can put te pump wherever you want...just make sure you don't ask it to LIFT beyond spec.

1970Columbia34 · #7 01-24-2007

it will be a flat run maybe with about 6"-12" of rise at the unit its self.

Cruisingdad · #8 01-24-2007

Cam,

I may be mistaken, but isn't it the longer the run the more the resistance? He should put the T-Hull as low as possible, and put the pump pretty close to the unit, right? The pump has to be below water line for an "easy to reprime"... which will happen quite a bit. 15 feet seems like a long run to me. However, it is the distance "up" that can be even more compromising.

Just my thoughts, though. I could be wrong.

- CD

1970Columbia34 · #9 01-24-2007

so your saying to mount my thru hull fitting near the motor the run my 15' hose to the pump located near the unit? I can do it that way to. The unit required min 250gph, and the pump i bought is a 500gph.

Cruisingdad · #10 01-24-2007

Scott,

Mine are mounted within five feet (or actuall closer) to my unit. They need to be below the waterline for ease of priming. You will have to match the gph with Mfg reccs. They should have that in their write-up or can answer. In my experience, it is not the GPH of the pump that is critical, it is the strainer(s) that clog up and have to be cleaned that shut down the pump. I think I mentioned all that in a differnet thread, though.

As far as its location, Cam could be right. He typically is (well, except about who makes the worlds finest yacht). Double check with the pump mfg for specifics. However, if it were me:

1) My T-Hull would have an outside strainer on it. http://www.westmarine.com/webapp/wcs...allpartial/0/0
It would be mounted low on the boat. It would have a "t" fitting that we discussed earlier.

2) Just outside of the T-Hull I would have a large Bronze strainer. http://www.westmarine.com/webapp/wcs...llpartial/30/0

I would NOT use that piece of junk little strainer they give you.

3) I would make the R-Water run to my a/c RW pump, which would be below the waterline. It is neccessary that this pump and the strainer and T-Hull all be easily accessible. I would put the strainer beside the T-Hull instead of beside the pump for ease of cleanout. The pump must be accessible to make it easier to reprime. The more accessible, the better.

4) Put your compressor wherever you want, but discharge to an easy to see location because this is how you will make sure you really are making/moving water and it is also how you will see if your water flow is getting impeded. I would not discharge underwater.

Hope that helps.

- CD