I had the good fortune recently to be able to observe some younger colleagues who are also employed in the whacky world of marine refrigeration and air conditioning. On reflection, it could be said that these and other members of the millennial generation may have become so immersed in screens and keyboards that they've glossed over the important step of grasping a thorough understanding of the actual machines. Maybe they didn't get the memo. Maybe they don't feel they need to, as it's all there on the screen. Or is it?

Refrigeration and air conditioning machines are incredibly dynamic devices where the operating parameters and conditions are constantly changing. Much of this type of equipment now features digital displays and controls that give the operator a comprehensive view of how the machine is performing at that instant in time.

But does the modern-day operator have a good enough basic understanding of the subject to be able predict events and performance rather than simply being able to read numbers on a screen? I am mighty impressed at the way some younger fingers can flit at speed through menus, sub-menus, etc., especially as most touch-screens don't seem to be sympathetic to my hardened and calloused fingertips.

But what are these young eyes seeing?

Last weekend saw another great Piss-Off competition at the Ft. Lauderdale International Boat Show, where the Europeans, Asians, and Antipodeans once again attempted to wrest the trophy away from long-time champions the USA.

In the land of silicone and testosterone, beer belly and Botox, avid boat builders proudly displayed their latest attempts at producing the most noticeable, noisy, and antisocial air conditioning water discharge possible.

Bonus points were awarded if the discharges were ridiculously undersized and so high that they could fill up a neighbor's dinghy or piss on to a dock and into the cockpit of the vessel on the other side.

RESULTS:

Last - Poorest performers of all were those kill-joy Europeans who seem to prefer not to join in the fun and actually want to hide their discharges underwater. I guess that in a way this adds an element of uncertainty as to whether the pump is working or the strainer is clogged, thereby introducing some mystery to the on-board experience.

     Yup, that’s the way it feels we’re being treated by shipping companies. Every package or pallet that ships from our warehouse is at the mercy of the carrier, because from the moment it’s picked up to when it’s delivered, hopefully undamaged, on time, and to the correct address, it is completely out of our control. They have the goods, and we the vendor and you the customer don’t. Your package is off on the ride of its life, and we can do nothing but hope and pray that it is safe and sound and not being held hostage or abducted by aliens.

     Our team spends considerable time and effort finding the best, safest, most reliable and most cost-effective way to ship packages, parcels and pallets. So, what could possibly go wrong?

There's a lot of talk of trade and trade agreements in the run-up to the election, but I've heard nothing of how the substantial anti-dumping and anti-competition tariffs applied to Asian solar products are protecting US interests.

Originally applied to just solar cells, these tariffs were expanded last year to also include complete solar panels made in China and Taiwan, and add a whopping 250% or so of duty to the imported price of all but a very few manufacturers of Chinese and Taiwanese panels.

The results of these tariffs are already being seen in the semi-flexible panels, popular in marine applications. Many of these low-cost panels suddenly shot up in price, and several outlets stopped offering them altogether, but the tariffs are not the only reason .....

     It's happened again, and I'm getting really tired of it. Yet another call from a boat owner who called in what he thought was a trained and experienced marine refrigeration technician to fix a poorly performing system, and now it's working worse than it was before! Why? Because the technician had added refrigerant, or "put in a shot of Freon" to what previously was a perfectly charged system.

     Our office here spends way too much time on the phone and in e-mails helping customers correct mistakes made by mostly well intentioned but misinformed and inexperienced technicians. Too often it seems that adding refrigerant has been a Hail Mary move, made after diagnosis was unsuccessful, and done in an effort to show the customer that at least something had been done. And that's where all the problems start ....

Down south they have Miracle Mussels ...

And lurking in many harbors are evil, vindictive, plastic baggies.

What do they all have in common? They can all ruin one's day by clogging sea water intakes and strainers for refrigeration or air conditioning.

Anyone who has ever had to rid a sea strainer of Sea Snot (AKA Sea Nettle; Jellyfish) will know that this can be an unpleasant task. I'm told that in the coastal waters of Louisiana, Alabama, and other areas of the Gulf Coast, mussels and other sea-critters can grow in numbers resembling an armada in a matter of days, clogging not only strainers, but hoses, intakes and much more.

The part floating, part sinking, part ready-to-clog-an-intake plastic bag, is also a nuisance, but typically gets sucked onto the outside of the intake thru-hull, and then floats/sinks away once the pump is stopped.

In light of the chaos these latent disasters can cause, it's no wonder that some boaters take serious measures to combat the threat. Plastic bags, like naughty schoolboys, are a mere annoyance, but swarms of Sea Snot are a real menace, and we see live-aboards in the Chesapeake fashioning domes out of chicken netting and positioning them over the sea water intake in an effort to keep the menace at bay (oh, pun eh?).

Coastal Climate Control now offers the very best in solar cable. But what does this mean?

Most solar cable available contains just 7 untinned copper strands, whereas ABYC requires a minimum of 19 tinned copper strands. The solar cable that Coastal offers is UV, sunlight, and ozone proof, and is extremely flexible due to the high number (100+) of tinned copper strands.

Minimum outside diameter and maximum flexibility are the keys to reducing the hassle of installing solar cable between the panel(s) and controller, and these cables are the very best we could find after an exhaustive search.

Available in AWG 12 and 5mm2 (AWG 10 equivalent) by the foot, or in cable sets with MC4 connectors already installed to connect directly with most types of solar panels.

Another great new solar offering from Coastal is the Philippi range of waterproof plugs and sockets. We are stocking a three-wire socket for attachment to the end of the cable from a solar panel, plus a corresponding three-wire plug to make a cable-to-cable connection. There is also a surface-mounted plug to make a cable-to-hard surface connection. (NOTE: Plugs and sockets are opposite to those found in homes, with the socket being on a flexible cord. The live, power-bearing component needs to be a socket for safety reasons.)

Recently, a customer contacted us for some troubleshooting advice. He said that his refrigeration system was not working and the compressor not running. Apparently he had a technician look at the system who reported that he checked the refrigerant level and said it was OK.

Now that may sound like encouraging words from someone the owner perceived would know a heck of a lot more about refrigeration than himself, but it demands some investigation.

Just like the laws of physics there are laws of thermodynamics, but these are almost incomprehensible to the layman, and appear to most of us as gibberish and gobbledygook. Nothing so simple as "what goes up must come down" and "for every action ..." yada yada.

You'd think that with only four laws of thermodynamics things would be easy, but even the numbering of them seems deliberately designed to confuse. The last of the four laws is the Third Law. There no half-laws, the First Law is the second, and the Second Law the third. The wayward law is designated the Zeroth Law and comes before the first law. (This feels a bit like trying to explain the rules of cricket).

Hidden in those laws somewhere is the revelation that (in very simple terms): if a substance exists in an enclosed environment in both liquid and gaseous forms, the temperature and pressure are directly related. Let's call this the Law of Fridgernomics for ease of association.

Are you confused about the wording on some solar panel guarantees and/or warranties? Well, you're not alone, but first let's define what is a guarantee and what is a warranty.

Guarantee: A formal promise or assurance (typically in writing) that certain conditions will be fulfilled, especially that a product will be repaired or replaced if not of a specified quality and durability.

Warranty: A written guarantee, issued to the purchaser of an article by its manufacturer, promising to repair or replace it if necessary within a specified period of time.

So a guarantee looks to be more like a loose promise, whereas a warranty is in written form and contains a guarantee with certain time limits. In this discussion we'll assume we're working with written warranties, whether packaged in with the product, or more likely these days, posted somewhere on a manufacturers' web site.

Well let's start back 20+ years ago when I was actively servicing marine air conditioning and refrigeration systems.

In the heat of summer, I'd often get calls mid-week asking to check air conditioning that wouldn't start during the weekend and that was popping breakers. When tested during the week, these systems inevitably worked flawlessly, but a quick look at the vessel's docking situation usually gave a clue to the problem.

Older docks with older wiring, plus "senior" boaters that need lots of air conditioning, equals voltage reduction issues on sunny summer Sunday afternoons, especially for boats at the far end of the dock. The more occupied boats there are with air conditioning on, the lower the voltage will be at the end of the dock.

Once the voltage is reduced below a certain point, the electrical load required to start an air conditioning compressor, especially older types of compressors, is often too much for weak dock power supplies. Small, often portable, generators also often cannot provide enough power to start a large air conditioner, although it will happily power it once the compressor is up and running. So, what can we do to help a compressor get started on a weak power supply?

Anyone with a refrigeration system on their boat or RV that is powered by a Danfoss (now Secop) BD35 or BD 50 compressor should be aware of the diagnostic diode function, which, with a simple flashing LED, tells you the fault reason that caused your compressor to stop.   Much of the following also applies to the BD80 compressor controller.

By connecting a simple 10mA 12v LED across the "D" terminal and a "+" terminal on the electronic controller attached to the compressor, you will have added a powerful fault-finding tool that may save you a lot of time and trouble later on.

Why the manufacturer elected not to incorporate a diode in the controller housing is anyone's guess, but Coastal Climate Control comes to the rescue here with three options:

1. A Coastal Diagnostic LED kit with an LED that you can either install permanently or keep in the spares kit.

2. A Merlin II compressor speed controller that also incorporates a diagnostic LED.

3. A Guardian digital thermostat/compressor speed controller that features a diagnostic LED

OK, so now you have some form of diagnostic LED installed, what is it going to tell you? If your fridge or freezer system unexpectedly stops working, i.e. other than the thermostat stopping the compressor, and you go take a look at the diagnostic LED, what exactly are you looking for?

This is a tale of two choices – new or rebuilt parts for electrical repairs.

We were recently asked by a marine air conditioning service company to quote a price for a replacement electrical box on a now obsolete chiller system. We were informed that the original box had been seriously compromised due to water ingress, and also that there were signs of some components, wires, and/or connections having scorch marks and other signs of overheating.This electrical box carries both high voltage and high current, and so carries a significantly high fire risk if compromised.

The servicing company ruled out any possibility of them rebuilding the electrical box on safety grounds due to its condition, and so sought a complete new, factory-made replacement. Unfortunately,

Remember back when you had to defrost your home refrigerator every couple of weeks? It was a fact of life. And then those frost-free refrigerators came about. No more defrosting!!

So why have we seemingly gone backwards in evolution and are having to defrost our boat's refrigerator/freezer boxes so often? Why can't our boat's fridge be frost-free too, you ask as you drape your frozen food in towels to keep it safe as you patiently wait for the ice to melt from your evaporator plates.

Natural defrosting is the only safe method, although a small amount of addition heat is OK, say from a portable inspection light in the box. Those who are impatient might consider using a hair dryer or heat gun, hot water, or, (shudder), an ice pick, but these are not recommended, as high heat and physical force are very likely to cause nasty and highly undesirable side-effects.

And who gets the finger pointed at them as the culprit for this lack of frost-free living? Why, the refrigeration manufacturer of course, although after reading the following, you may shift the blame elsewhere.

Mounting solar panels on hand rails around a boat's perimeter allows for some flexibility of use, plus the opportunity to angle the panels if you happen to be a dedicated twiddler with too much time on your hands. But when using standard aluminum-framed glass panels, necessity dictates that the clamps that secure the panel to the rail must be on the center-line lengthwise.

Glass panels are pretty heavy, and too much twisting and torsion will either "soften up" the aluminum frame or cause the glass to crack and/or shatter. Most panels of this type are designed to be installed on solid, permanent structures like roofs (specialized marine panels like the Solara Ultra series being an exception), and it is assumed that these land-based platforms will not heave, pitch, twist, or generally rock-and-roll (barring earthquakes) like a small/medium sized boat often does.

With this in mind, having a balanced mounting point is essential when using glass panels in rail-mount applications if regularly having to replace panels is to be avoided. But having a balanced mount, i.e. with the rail clamps on the center-line lengthwise, means that half of the panel's width will be intruding into the walkway, cockpit, etc. when deployed, and the wider the panel the more it will become an obstacle to movement.

Choosing a narrow panel is one way around this dilemma. Here's one way to do it:

Oh boy, if only that were true! But unfortunately there is no such thing, and so comparing the performance of one marine air conditioning manufacturer's product to another comes down to comparing the manufacturer's published specifications.;

Keep the following in mind if you are in the market for air conditioning for your boat.

Q – How can I be sure that a 16,000 Btu air conditioner from Brand X actually produces 16,000 Btu of cooling and heating?

A – To be blunt, you can't! If it were a residential or commercial unit you'd be assured of the capacity rating as there are strict compulsory standards in these industries, but not in the marine business.

A marine air conditioning manufacturer can label his system as whatever takes his fancy, which is usually dictated by marketing strategies. If only we had that "Btu Meter" to assess performance .....

Q – But surely there must be a base-line for a prospective buyer to be able to assess one manufacturer's system against another's.

A – Yes there is, it is the compressor. Every compression system has a compressor, and every compressor manufacturer publishes performance data for their individual models. Most marine air conditioning manufacturers simply use the compressor's Btu rating in determining what to label their products.

That's a simple solution, but

When the seasons change from Spring to Summer, there is always a certain amount of reluctance to fire up the air conditioning in our house until it's absolutely necessary.

After being closed up for the Winter, having fresh air blowing through the house is so refreshing that no one is in any rush to seal off the outside world again until things get too uncomfortable.

The comfort issue for me is more a matter of excessive humidity rather than temperature, and when it gets to the point that I can feel the curtains and furnishings getting heavy and limp with moisture, I know that it's time for the air conditioning to come to the rescue.

Last year, before turning the air conditioning on, I placed a gallon jug under the condensate drain to see just how much moisture would be removed during the first hour. Our 30,000 Btu (2.5 Ton) system for our ground floor removed 1 gallon in the first 45 minutes, which equates to 1.33 gallons per hour.

Our last blog explained that condensing the moisture out of the air is not a free additional benefit of cooling the air, as it comes at a hefty price.

If you didn't know it already, the term Btu stands for "British thermal unit". I don't know what gave the Brit's the right to have their own thermal unit, but let's hope they don't ask for it back any time soon, as it is so much easier to comprehend than the metric equivalents using Joules, Calories, etc.

It's common to see the cooling and heating capacity of air conditioners, refrigerators, furnaces, etc., being shown by their Btu ratings or Tons (1 Ton of refrigeration = 12,000 Btu), but what exactly is this Btu? What does it look like? And does The Queen have one?

Simply put, one Btu is the amount of heat required to be added to, or extracted from, one pound of pure water in order to raise or lower its temperature by one degree Fahrenheit. This is about the same amount of heat as given off by a match that's used to light a fire.

So, if we have one pound of water at 100°F and add 40 Btu to it, its temperature will rise to 140°F. If we removed 40 Btu's from our one pound of water, its temperature will drop to 60°F. If you are all following this so far it's not too surprising, as what I've described above is known as "Sensible Heat", and, as you are already reading this, then obviously you are all very sensible people!

Now, if we keep on adding Btu's to our one pound of water, it will keep rising in temperature at a linear rate of 1°F for each Btu added until it starts to boil, which at sea level will be 212°F (100°C).

At boiling point something very interesting happens....

Most marine refrigeration, and all Frigoboat systems, use the Danfoss BD 35 and BD 50 compressors which are incredibly reliable machines and very robust. It takes a lot of abuse to "kill" one (they don't simply die from natural causes), so if you suspect that your compressor is faulty, it's important to know how these compressors work, how they can be damaged, and what symptoms to look for.

The Danfoss BD 35 and BD 50 compressors are identical except that the BD 50 has a little more cubic capacity and therefore a slightly higher Btu rating. The compressor and motor are hermetically sealed inside a steel canister and supported on vibration-absorbing springs. There is no shaft seal that could leak refrigerant.

COMPRESSOR – The compressor is a single-cylinder device with a crankshaft that when rotated pushes a piston in and out of a cylinder, compressing the gas. A simple valve plate allows gas to be drawn in on the down-stroke, and the gas to be compressed and then released on the up-stroke. The compressor assembly is mounted above the motor, and the vertical crankshaft is a continuation of the motor shaft.

MOTOR - The compressor crankshaft is rotated by means of a poly-phase inductively coupled motor that has no brushes to fail or wear out. There are three sets of windings arranged around the stator, and the ends of these windings terminate on a three-pin connector that provides for the electrical connection through the compressor shell. The rotor is built around the shaft that connects directly to the compressor crankshaft.

ELECTRONIC COMPRESSOR CONTROLLER – Also known as a "module", this is a vital part of the compressor, and the motor cannot run without it. The controller is mounted on the compressor on a special bracket, and secured with a screw. It is electrically connected to the motor via a three-wire plug that is pushed on to the three-pin connector on the compressor shell. The compressor controller basically takes the 12v or 24v DC input and energizes each of the three windings in turn, causing the motor shaft to rotate. Varying the speed at which the windings are energized varies the speed of rotation of the shaft.

So what could possibly go wrong?

I've just come across yet another sailing magazine article giving inaccurate and misleading information on solar power for boats. (Why don't they bother to do some research and ask the real experts?) So here is a list of ten myths and busts in an effort to set the record straight.

MYTH 1 - Glass solar panels with aluminum frames are the most efficient

BUST - No, no, no! The type of cell determines how efficient a solar panel is, not how it is constructed. Coastal offers three types of panels all made with the highest available efficiency SunPower® cells:

1) aluminum-framed glass panels,
2) razor -thin walk-on panels, and
3) flexible panels for installation in canvas areas like biminis.

All three types enjoy the same high efficiency because they all use the same cells with 22.5% efficiency. Glass panels are more common and less expensive, but not necessarily more efficient.

MYTH 2 - You can't walk on solar panels.

Which marine refrigeration system is better when cruising in warm waters: air cooled, pumped-water cooled, or Keel Cooled?

A well designed and fabricated air cooled refrigeration system, like the Frigoboat Capri 50, should be able to maintain refrigerator and freezer temperatures in the tropics if the application, installation, and operation are all within the manufacturers' guidelines.

But in tropical/Caribbean conditions, air cooling will be 25% to 35% less efficient than water cooling. As a result, the overall power consumption of an air cooled system will be considerably higher than for a pumped-water cooled system, and very much higher than for a Keel Cooled system.

Many serious cruisers these days install hybrid Air-plus-Keel Cooled systems, where the air cooling is only used when the boat is hauled for any reason. For a new installation, this could be a Frigoboat Capri 50 installed together with a Keel Cooler, with a switch installed in the fan circuit of the Capri 50. Existing Frigoboat Keel Cooled systems can be easily converted to an Air-plus-Keel Cooled system by installing an Air Add-On condenser. This is accomplished with the use of just basic tools, and without any adjustment to the refrigerant charge.

If your boat is aluminum, then due to corrosion considerations that prohibit the installation of a Keel Cooler, you would be best served by installing a pump-water cooled system like the Frigoboat W50. That, together with the Air Add-On air-only condenser for use when hauled out, will provide the same efficiency as a Keel Cooled system, although the added current draw from the water pump will negate some of the power savings normally experienced over an air cooled system.