Got some good work done on the 12000 BTU HVAC

Early of March 2013 – At anchor in the Bahia de Navidad lagoon

Because time is ticking away and we want to have our AC working for the summer, we decided to start working on the install of the final A/C unit. The Mermaid 12000 BTU unit that sits in the salon. The Mermaid 5200 BTU unit is installed and working in the stateroom and head. Both are completely separate from each other for back up.
 First we decided to install the supply grill. This is the gril that the Mermaid AC and Heat (HVAC) unit uses to get the air to cool from. We are definitely limited by space on the locations of all this as it being a boat and an old boat at that.

 The only spot that the HVAC unit fit we put it in (under one of the salon seets) and the only place the supply grill fit we put it.

First Debbie cut  out a template for the outside and a second one for the insert part for the inside.

We had to re-locate or at least move for now the mast wiring.

Debbie held the engine raw water loop hose out of the way while the cuts were being done.

We had space to work so we drilled a few holes and used a jig saw then the Japanese saw.
The we put some teak oil on the grill so it would blend it better for now.

Next Debbie hunted down some screws and lock nuts and regular nuts and washes for the ducking flange from the HVAC. She then temporarily installed the flange.

We then did a mock up of how we want the ducting to run. The HVAC unit has some requirements as to how far the first duct can be from the unit and what size it must be, also how many ducts need to be installed.
Debbie then made a template of the insulated ducting size for the hole we needed to make. The ducting that is silver we hope to not use (as it's not insulated). If we have enough insulated ducting we will use only that. The silver ducting was easier to work with for mapping out the ducting.

After deciding roughly where the ducting should go we had to move some plumbing.

Now we had known how we wanted to run the ducting before it was just a matter of if we really could and exactly where it would go so we could make the cutouts.

We also had to cut one side off the teak grill so we could fit it in. This you can not see unless you get on your knees and we will finish it off nicely.

Now that we know exactly where the first return grill is going we had to make a cut out for it. This required another two templates that Debbie made and some figuring. We made the marks and had to use the drill to make a series of holes that we then could connect to with a hack saw blade. Remember we are at anchor and have a limited amount of tools. That done we used a rasp to finish off the fit so the grill would slide in.
This time we used a drill and then a hack saw blade to make the hole. Then a rasp to finish it.
Not that easy.

After we fit the grill it was obvious the grill would require a second trim on each side. Either the grill or the teak on the salon front. The grill was much easier.

That done we sanded the edges and later applied teak oil
to the cuts and grill and wa la - it is fit!

Next was the hole for the ducting to run past the hot water heater and around the salon. There will be a grill in the galley and one in the upper part of the salon on the shelf. That is a plastic circular one that is installed but no ducking. The teak grill and the transition box for the galley we cannot find. I know they were on the boat and we will find them. I mean how do you lose stuff on a 36 foot sail boat???

Debbie moved the head toilet plumbing and removed an old T
that we were not using any more.

Then Debbie installed a different valve and a new hose to connect to the fresh water system. Then she moved the fresh water hose to the heater and connected them all together. We then staked it all down so it would not move.

Back together for now, more work to be done.

This work we did over a series of three days. Each morning we would work till about 1:00 PM then go play.


  1. It will be interesting to hear how well the unit works, but I'll bet any relief will be better than nothing.

    Don from FOGgers

  2. looks good! hope you are having fun! sorry i didnt get a chance to say good bye b4 you left! all is well with me

    take care,
    randy (enay)