IP38 A/C

Hello IPYOA - First post! Happy to finally be an IPYO...

I see that I'm not the first seeking advice on installing A/C on my IP38. Has anyone out there personally done the upgrade themselves?

Defender is having a deal on "MARVAIR" units for Activecaptain subscribers, and I was wondering if now was the time to get an A/C installed.

Information I'm seeking:
- Where best to install the unit (Consensus seems to be port side behind settee)
- 1 or 2 Units? (I'm thinking a single 16,000 BTU would be enough to cool most spots on the boat)
- BTUs recommended for each case?
- Raw Water Source (Not thrilled about cutting a new thru-hull - thinking head intake or possibly salt water washdown)
- Duct Routing options
- Recommended Brands (If not the MARVAIR)

Thanks for any insights you can provide - I need to get cracking on this project before the weather (Finally) turns nice.

-JP

i'm looking at the same thing for my IP31. i have the same questions. my buddy warned me there is still about $500-800 more parts and stuff to install the entire thing, pump, ducts, grills, plumbing supplies- existing inlets sound good to me too.

I think that with the price at which Defender is selling these units(Sub $1000), the extra $500 - $800 seems reasonable, considering a comparable 12-16k BTU Mermaid, Dometic, or Cruisair will set you back some $2000 without even the installation kit. But I'm wondering if anyone has any experience with the Marvair units and can either attest to their quality or lack thereof. In my experience, especially with boat/yacht stuff -just because you can't find it on the interwebs doesn't mean it's of low quality or value.


I'll probably be asking a similar question when Electric Windlasses go on sale...

Just a thought on raw water intake. It is always best not to use the raw water intake for the engine for anything else. It should be dedicated only to the engine. A leak in any other component, such as the pump seals for the head, could allow air int the system, and suction loss resulting in engine overheating. I took the factory installed raw water intake for the head shared with the engine off my seacock.

I believe (not on the boat at the moment) that the only consumer of the engine raw water seacock is the engine. Perhaps I should have chosen my words more carefully with regard to my use of the word "raw water ." What I had meant to ask was where is a good source of cooling seawater that doesn't involve me cutting a new through hull?

My thanks to emergpa1 for reminding me not to do something stupid in the effort to find the best source.

Yep- the IP31 intake is shared by the engine and the head

On my 38 (-181) I have two reverse cycle units (heat and cold) installed. I have a 16K BTU cooling/heating the main salon installed under the galley sink. It has two blower vents on the stbd side, one forward above the forward setee seat, and one aft just forward and above the stove. I have a second 9K BTU unit installed behind the port aft setee with two blower vents on the port side, one in the aft stateroom on the high shelf and one in the forward stateroom also on the high shelf. I'm in Maryland where temps routinely hit 90-100 in the summer. I've tried it with temps in the mid 90's, and the single 16K BTU unit would could not keep up until the sun set. Might be OK in Rhode Island but probably not further south. It's never been hot enough with both units running where I couldn't keep the temps in the low 70's.

Also, the engine intake has both head intakes connected. Never had a problem with that. I have a separate single through hull for both the AC units located on the stbd side opposite the engine intake. Believe it fits a 1 inch ID hose. That leads to a strainer and cooling water pump, both installed near the top of the bilge in the aft stateroom, accessible via the forward access cover over the bilge. Plus you need an above the waterline overboard through hull for cooling water discharge, one for each unit. Those fit 5/8 ID hose. One is in the aft head cabinet next to the sink drain through hull, and the other is under the main galley sink cupboard, next to the galley sink through hull.

Hope this gives you some ideas.

Well - that certainly is a lot to think about.

I went ahead and pulled the trigger on a 16000 BTU unit - so now I have some options going ahead. Not sure that I want to sacrifice all the storage under the galley sink - though I suppose a shelf could be constructed to minimize the impact...

Rhode Island is where I call home, for now, so I'll give the single unit a shot and see if it's going to be adequate for our needs. It very well may be since we have the benefit of both the milder air and sea temps, making A/C much more efficient. However, since it would only be a single unit, I'd need to figure out how to run ducting into AT LEAST the forward Stateroom and somewhere in the salon/galley - with the added possibility of expanding with a smaller second unit. We'll see how it goes - I'll dig around and see what I can come up with - though any further suggestions would be very welcome - particularly single unit solutions.

Lastly - I too have a through-hull opposite the Engine Raw Water Intake. it appears to be a mod one of the previous owners had installed quite a few years ago. This feeds a number of seawater systems - again, I'm not currently on the boat - which I believe includes the heads. The previous owners did a great job in making some "common sense" mods - of course without considering to add a/c...

Something you might want to consider is a Mermaid Condensator. This installs in the water line between the A/C unit and the overboard discharge. It T's down to the condensation drain and sucks any condensation overboard. Both our A/C units were installed to drain into the bilge and we ended up fighting that and the stink of stagnant water for 4 years. We live aboard and run our system 24/7 and within a week we'd have 10" -12" of water in the bilge. Just now installed the two Mermaids and it's made a huge difference. The boat smells clean and the bilge stays dry (mostly).

We have two units on our 420 but the forward one has always had problems, never works in the Summer high heat. We've managed OK just running the bigger unit out in the salon and pushing cold air forward with a fan. We finally got it straightened out but If you were to run a duct up to the forward compartment I believe you'd be OK with just the one unit. We reprogrammed ours to run slower than the factory settings for quiet operation and the boat stays very comfortable. Ours are Cruisair units.

Tom Ward
IP420-35
La Vida Dulce