Saturday, March 3, 2012

Solar Vent Installation

Over at Captn Pauley's, he has just installed some vents and has some excellent information regarding vents. Take a read and pop over for more info.
Here is his installation.

The vent installation is quick and easy. My daughter and I installed one vent in less than an hour.

The first step is to cut the hole needed to mount the vent. The nominal three-inch vents I purchased called for a 3-3/4 inch diameter mounting hole. This hole can be made by using a hole saw or with a saber saw. Hole saws these diameters are not stocked in your local home improvement store. I purchased mine on line from Jamestown Distributors (, one of my favorite on-line tool suppliers.

I made an “X” of masking tape in the approximate center of the mounting area and then measured the center exactly, marking it on the masking tape.

If you use a saber saw to cut the hole, mark the diameter with a compass and then drill a clearance hole in the center to start the saber saw cut. Cut slowly and keep to the line as accurately as possible.

Using the hole saw, I first removed the outside hole cutter and drilled a pilot hole. After re-installing the hole cutter, I centered the hole saw in the pilot hole and proceeded to cut the finished hole. I was careful to keep the hole saw level with the surface of the hatch and cutting evenly.

The next step is to take the vent apart to access the base and mounting holes. The top cover, including the solar cells, motor and battery, are removed by taking out three screws. These screws have small O-rings around the heads; don’t loose these as they seal the seals and motor.

Removing the top cover leaves the vent base and its three mounting holes. I placed the vent base, centered in the opening, and drilled the three mounting holes through the hatch. I used 10-24 stainless steel machine screws through the base with nylock nuts on the bottom side.

Here is a hint, after you drill the first hole, place a screw in it. Then drill the second hole and place a screw in that hole. That keeps all the holes in alignment.

With the mounting holes in the hatch drilled, I turned the vent base upside down and applied a thick bead of sealant around the mounting spigot and the mounting holes. My sealant of choice in this application is BoatLIFE LifeCaulk. After poking the three 10-24 screws through the holes, I placed a neoprene rubber washer on each of the screws.

These rubber washers are key to getting a god seal around the base of the vent. They allow the vent mounting screws to be tightened but prevent squeezing out all the sealant. A thick sealant line is necessary for a long lasting installation as it accommodates the different rates of expansion and contraction between the hatch and vent.

Once the vent base was properly mounted, all I had to do to complete the installation was to fasten the top cover back in place, making sure the O-rings around the mounting screws were still in place.

All told, installing a solar vent like this took about an hour start to finish. I got them both installed just in time for our current heat wave. Both fans are busy moving air through the cabin around the clock.

Friday, March 2, 2012

New iAIS Receiver and Wireless Mulitiplexer for your iPad

I have shown elsewhere on this blog site, how a wireless multiplexer from Brookhouse, call an iMux, can be used to serve data to your iPad etc. Here is another similar device by Digital Yacht along with a couple of video's to help explain.

Digital Yacht's Description
The world’s first wireless AIS receiver that links wirelessly with the latest iPhone, iPad and iTouch devices. Consisting of a high performance dual channel AIS receiver, an integrated 802.11b+g wireless access point plus a free app downloadable from the Apple App Store, the iAIS brings AIS data to a whole new generation of mobile devices.

iAIS also multiplexes any other NMEA data that is available on board the boat - for instance GPS, depth, speed and wind etc. All of this data is combined with the AIS data into a single wireless feed, that becomes available on any compatible application. By using the boat’s own GPS, even an iTouch or iPad that does not have an internal GPS can now be used for navigation and superior performance will also be seen on an iPhone, which some users have complained suffers from jitter or poor lock-on with its internal GPS.

As well as sending data wirelessly, the iAIS also has an NMEA0183 and USB interface so that you can output data to a PC (via USB) and a dedicated plotter (via NMEA) for larger installations.

The free iAIS app is available from the App store and is a simple AIS display program. For more advanced use, Digital Yacht recommends the iNavX app ( Compatible with Navionic’s charts, iNavX provides a complete set of navigation functions that turns your Apple device into a full function electronic chart plotter. It supports waypoints, routes and tidal data and is beautifully simple to use. It even overlays GRIB weather data. iNAVx sell and support this app directly and the cost is just $49.95 (click here).

World’s first wireless AIS and NMEA Data server
Tri-output; WiFi, NMEA 0183 and USB
Multiplexed NMEA input for wireless NMEA data feed of boat’s instrument and GPS data
Free iAIS App for iPhone, iTouch or iPad
Integrated 802.11b+g wireless access point
Fully compatible with popular iNavX navigation application for Apple mobile devices
Rugged IPX5 aluminium housing
Requires VHF antenna or dedicated AIS antenna (available as optional accessory) or splitter
Simple “fit and forget” black box solution

* NOTE - AIS target range, like VHF range is dependent upon a number of installation factors such as; antenna gain, antenna height and size of ground plane. Ranges in excess of 20-30 miles should be possible if all of these factors are perfect.