A Different Kind of Cold

While researching the various systems in my RV, I managed to find an installation manual for the refrigerator and it emphasized the differences between a typical household refrigerator and the kind you'll find in an RV. Those of you who have no interest in getting an RV may find some of those differences useful if you're looking for a refrigerator/freezer for a remote cabin or other “off-grid” living quarters.

Most RV refrigerators will run on either 120VAC power or propane (LP), while a few models like mine will add 12VDC as an option. It may sound strange, but they actually cool the inside of the refrigerator by heating up a “boiler” using a propane flame or an electrical heating element. The method of cooling is called “single pressure absorbtion refrigeration” (SPAR) instead of the conventional“vapor compression” method (VC)used in air conditioners and household refrigerators. Here are a few of the differences:

A conventional VC system uses a compressor/condenser unit to turn gaseous Freon (a generic name for a family of fluorocarbons) into a liquid, then pumps the liquid through an expansion valve which causes it to turn back into a vapor. The change from liquid to vapor is known as a “phase change” and requires quite a bit of heat to accomplish. The liquid gets that needed heat by pulling it out of the inside of the refrigerator, cooling the contents. The hot vapor is then routed back to the compressor, which further heats it as it compresses it back into a liquid, and finally to the condenser where the excess heat is exhausted to the outside air.

A SPAR unit uses two gasses (usually hydrogen and ammonia) and a liquid (water) that absorbs one of the gasses, all kept at roughly the same pressure. The ammonia, in liquid form, absorbs heat from the inside of the refrigerator and changes phase to a gas. That gas is absorbed by the water, which is then heated in a small “boiler” to drive it back out of solution. The gaseous ammonia condenses back to liquid form in a condenser and flows back to the heat exchanger inside the refrigerator. The hydrogen serves as a carrier for the ammonia and eliminates the need for a mechanical pump to move the liquid ammonia. SPAR systems have no moving parts, so they will last a long time. There is no compressor, and the condenser is a lot smaller, but in return efficiency takes a dive; SPAR units are only about a third as efficient as VC units, which is why SPAR systems are rare in houses today. 

My grandpa used to buy Servel refrigerators that ran on kerosene, back in the 1930s and 40s. I've heard that they would run on as little as a quart a day. You can still find them for sale on eBay and Craigslist, but they don't meet all of the current safety regulations and the safety nannies are trying to get them off of the market. Servel was the brand name used by Dometic, which is the major maker of SPAR systems in the world, for their household appliances. They still make them, but they are all propane-fired now. A full-sized refrigerator will burn about a pound of propane each day, so a grill-sized 20 pound cylinder would last about two weeks (they never fill cylinders more than 85% full [17 gallons] for safety reasons).

The VC system uses an electrically driven compressor, which requires a big surge of power to start. The SPAR system will have a control board and ignition coil that require electricity, but most of that is 12VDC. RV systems generally have a 120VAC heating coil to replace the propane burner when you are hooked up to the grid or running a generator, mine also has a 12VDC heating coil as an option, but it is not rated for the full cooling capacity and the manual advises using the DC option for no more than 6 hours. Electric heating elements are not efficient, and I avoid them wherever possible.

VC system have a compressor, which is a sealed unit with moving parts inside. There is no maintenance, when it dies it has to be replaced and that usually costs more than a new refrigerator would. Compressors can be noisy when they run, whereas a SPAR system is almost silent (unless you're using a generator to power it).

Cost can be an issue. Since SPAR units are targeted at the RV market, their production is nowhere near that of VC units. Economy of scale knocks the price of VC units down to half or a third of a comparable SPAR unit. SPAR units also tend to be smaller, somewhere between a dorm fridge and a house fridge. The smaller size is a plus for me, it means that the refrigerator will get cleaned out more often and there's less of a chance of leftovers getting lost in the back of a shelf.

If you're on a budget and still trying to put together a bug-out location or a bug-out vehicle with cold food storage, keep an eye out for people scrapping or parting out an older RV. It's hard to kill something with no moving parts, and replacement circuit boards are still being produced for a lot of the older models, so a used RV fridge might fill a niche if you have medication that needs to be kept cold or just want to enjoy a cold beer (or have ice cubes in your lemonade) as you watch the world fall apart around you.

Vacation Time at the BOL

I don't normally take what most people would consider a vacation. The last time I took the family on a vacation was about 15 years ago, and that was a two-week road trip to visit more family. To me, just getting away from the normal day-to-day routine is good enough, but it always seems to come with work attached. I have gotten used to this, and I actually look forward to being able to practice skills that I don't use very often (carpentry, fence-building, tending animals, etc.) when I get the opportunity.

This year my “vacation” will consist of a week of watching the family farm (18+ acres of hills and trees with some pasture) so my Dad can go on a fishing trip. Since the family farm is my primary bugout location (BOL), this will give me a week to inspect, repair, and improve the various pieces of the property that make it a good candidate for a BOL. I will have to work my regular job a few of those days (staffing issues prevent me from taking the whole week off work) so I won't have as much time as I'd like, but I plan on making the most of the time I have.

My tentative plans include:

Check the Perimeter Fencing

Around here, the responsibility for maintaining fences follows the “right-hand rule”: as you look at a fence between your land and a neighbor's, you are responsible for the half of the fence on the right-hand side. Your neighbor is responsible for the other half, which will be on his right-hand as he looks at the same fence from his property. Clearing trees that have fallen on the fence is the biggest part of this job, with replacing the whole thing a close second. Replacing posts and patching barbed wire is a simple job, but getting to the fence can be a challenge in the rolling hills we have.

Update and Improve the Computer Network

I recently switched the farm over to a DSL line from the annoying and expensive dish internet. This saves about $60 a month, and there are no more data caps or speed issues in bad weather. I can understand using the dish internet if that is all that is available, but it has a lot of problems.

I still need to install a new wireless router and do some map work to plan for wider wi-fi coverage. My goal is to have at least minimal wi-fi available for security cameras that can cover the entire acreage. Even without internet access, once the network is set up I will be able to monitor what and who is moving around on the property.

Check and Maintain the Backup Generator

I bought a generator big enough to run one freezer, the refrigerator, and about half of the lights in the house several years ago when we had area flooding threatening the power supply. Mom was diabetic and needed a way to keep her insulin cold, so I bought her a generator. As far as I know it has only been used a few times, and I need to change the oil and make sure it has been stored properly.

Prepare the Area for Fruit Trees

There is a patch of scrub cedar trees that needs to be cleared and replaced with plum trees. Not too far from there is a spot with decent southern exposure that may be cleared for apple and cherry trees, but it is grown up with Prickly Ash saplings. Cedars are easy to cut out, but Prickly Ash is hard to kill; it likes to re-sprout if you don't kill the roots. I may have to invest in some agricultural chemicals capable of doing the job, but first I need to figure out how much space I want to clear.

Repair/reroute the Access Road to the Hilltop

There is a 2 acre flat spot on the top of the major hill, but the road or lane leading up to it is in bad shape; several years of neglect and too much rain have taken their toll on it. I own a surplus M35A2 2.5 ton truck and it can't make it up that road right now. It's time to survey a new route that will avoid the potential for rapid runoff during rainy years, and perhaps try to patch the path we already have. I'm not totally comfortable with only having one way in or out of an area, so I may do both.

Rebuild the Family Shooting Range

One of the valleys has become the family shooting range. With a 60' high hill for a backstop and about 150 yards from side to side, it is sufficient for informal weapons practice. I need to rebuild the target stands, and may lay out space for some permanent shooting benches to be built later. I also need to clean up after a few nephews who don't pick up their trash when they're done and have a talk with them about the paintball obstacles that have recently appeared.

Pest Eradication

Since the house at the farm is in the country, insects and rodents are a constant problem. The cats keep the small rodents at a manageable level, but the spiders and other bugs have gotten out of hand in the garage and (rarely used) basement. 

I have found an insecticide that will kill a wide variety of insects without the odors and hazards normally associated with bug sprays. Being FDA approved for use on food plants, and having a 90-day residual kill, makes this a good option for keeping insects out of a house.

This will be my test run for a future product review of that insecticide.  I'll see how well it works.

Have a Bonfire

One of the nights I am at the farm I will burn a brush pile that has accumulated for the last year. I may invite a friend or two over and sit around the fire drinking a few beers, or I may just sit and watch it burn by myself. 

This has been a rough year for me, losing my Mom, father-in-law, and two aunts within a month. I've also seen three acquaintances buried since Easter, and I think it may be time to sit by a fire and reflect on all of their lives. Some of us need to be around others to mourn, and some of us (like me) need to be alone.

The weatherman is calling for rain most of the week I'll be at the farm, so I guess I'll just have to see how much of my list gets accomplished. Some of it I can do from inside the house, and there are always other things to do to keep me busy if that's what I want.