My choice was made three years ago, not sure if anything has changed in that period or not, but for what it's worth:
One fundamental difference between them is the way that the thermostat works (worked?): on the Mikuni, when it gets too warm, the heater cuts out, then when it cools down it goes through the restarting cycle again. On the Eberspacher works so that the heater is progressively cut down to a lower level of power, and only cuts out if things nevertheless stay too warm over a longer period.
Because most of the consumption in both models occurs in the start up cycle, my rough calculation was that that Eberspacher, because it would be going through the start-up cycle more rarely, should in fact be less thirsty. Secondly, the Eberspacher should have less violent fluctuations in cabin temperature, as the Mikuni would have to wait before starting up until the temperature had dropped significantly before starting the cycle again. Cosmetic impression was also that the Eberspacher was better made, so I chose it.
Downside was that the Eberspacher was more expensive, but then I took advantage of a Boat Show offer that made the difference negligible.
Hope that helps /forums/images/graemlins/smile.gif
Fitted an Ebberspacher Airtronic to my boat 3 years ago...the best thing I ever did, dont know how I sailed without it before. I have had no problems with mine but if things do go wrong spares are not cheap!!!! Most problems occur due to neglegt and lack of use. I find if you use it as much as possible (thats easy up here!!) and run it as hot as possible you seem to have little problem with it...basically if you look after it it will look after you.
I've been using Eberspacher heaters for approximately 15 years and swear by them as opposed to at them. I'm using an Airtronic in my latest boat and it is excellent: touble free and efficient. I've heard other people moan about them but I've always had mine professionally installed and I've always been delighted with the results.
My Eberspacher D2 has gone wrong after 3 years, but I guess some always will. The only problem is the spares are expensive, the control box we need for ours is over £200+ VAT.
If anybody knows a cheap source, I would be grateful.
While it was working, it was great. I would be really careful about who you get to install it and if it is in a locker make sure that all the wiring, fuel lines, heater hoses are properly led so that they won't get damaged by putting things in the locker. Our's was professionally fitted, but even on our recent survey they commented that it was an untidy installation.
I installed mine myself. I'm not a particularly technically minded person, but spending a bit of time thinking about it beforehand, using common sense, and laying everything out before drilling any holes meant it went smoothly enough.
I have only had one problem so far (touch wood), but having done it myself helps to take away some of the mystery and in that case meant I solved it myself at zero cost (by finding the contact I hadn't vaselined properly, and cleaning and greasing it). I spent quite a while thinking about positioning and how to run pipes so that there was absolute minimum encroachment on locker space, and to make it reasonably accesible for future maintenance etc. A professional might have done the same, or better, but then again, I suspect he might have been more interested in getting the job done as fast as decently possible and getting home.
In terms of build and design quality there's no competition - the Eberspacher is streets ahead.
In terms of value-for-money it's less clear-cut.
Not only are Eberspacher heaters' street prices far more expensive than Mikyuni, but their spares prices are also in a different league.
If you want a more comparable heater to the Eberspacher look at Webasto, equally well-made, slightly less cutting-edge technology and even more reliable.
Personally, having owned a couple of Eberspachers I opt now for an electric fan heater when on shore power and an all-fuel stove for other occasions. That combination is good for -8C ambient which is more than the Eberspacher could cope with.
Sounds like you've found a good combination, but would like to correct one thing: last time I was aboard was about -8 deg C, and my Eberspacher had no problem coping (I slept on board even though the boat was out of the water, everything frozen - the Riga winter is quite harsh). That included running it through the night on a low power setting. Also, that's bearing in mind that a 32-footer is towards the large end for the recommended size for it (I think it's the D2 model, if I remember their numbering system correctly).
Yes, I wouldn't recommend keeping the hatch open for long in -8. But some opening is necessary to provide some way of air getting out. After all, the heater is blowing a powerful stream of air into the boat, so the boat might eventually burst if you don't /forums/images/graemlins/wink.gif
Some people install them so they recirculate the air in the cabin, but the result is much better when they can draw in fresh air. The air in the boat is healthier, to start with, and the build-up of moisture (and hence condensation) is reduced.
... and Eberspacher recommend in the installation instructions that air should be taken from outside. Seem to remember reading somewhere that it could be potentially dangerous to take air from the interior?
[ QUOTE ]
Seem to remember reading somewhere that it could be potentially dangerous to take air from the interior?
[/ QUOTE ]If so then they would presumably also have us believe that it is dangerous to live in our boats without a mechanically assisted fresh air system when we don't have an Eberspacher running? Or are they arguing that the Eberspacher burns up significant amounts of O2 that needs to be replaced mechanically? Very strange since presumably any air drawn into the combustion chamber from the living accommodation will be replaced from the outside, unless the interior of the boat becomes a vacuum /forums/images/graemlins/grin.gif
I think the main reason (apart from PVB's points) is in case of a malfunction in the unit that leads to fumes from the burning process being mixed into the expelled air, in a closed loop it would become more and more polluted with each circulation. But perhaps someone with more expertise than me could comment?
I don't undertand your comment about a vaccuum - the unit is pumping hot air INTO the cabin.
*FUEL HEATING SAFETY - Carbon Monoxide and combustion exhaust ventilation
FUEL HEATERS FOR YOUR BOAT OR RV
There is nothing dangerous about taking air from the inside to heat it in a proper heating device. In fact we heat our homes and buildings by heating the inside air. It's the only efficient way. We don't heat outside air for the sake of efficiency. Most boats and RV's are all about efficiency and conservation of fuel resources. Here's what's supposed to happen, and what's not supposed to happen:
Perfect hydrocarbon/oxygen fuel combustion produces only water and carbon dioxide. Unfortunately, almost all combustion is far from perfect. Carbon Monoxide (CO) is also produced; There is also a collection of un-burned fuel, and new hydrocarbons. All these are in varying percentages depending on the temperature and quality of the combustion. All these by-products of combustion (Water, Carbon Dioxide, Carbon Monoxide, Hydrocarbon mix) are undesirable inside a boat, RV, home, or any space occupied by animals). Carbon Monoxide is a very poisonous gas that binds with blood hemoglobin faster than oxygen, and permanently -*it's a good way to kill yourself!*Water from combustion will increase the amount of heating requirement due to increasing humidity, and also set up favorable conditions for mold and mildew. Carbon Dioxide is what regulates breathing response - increased levels will cause all sorts of difficulty in breathing/respiration. Un-burned Hydrocarbons - well that should be obvious.
Any hydrocarbon fuel heaters (Espar/Eberspacher, Mikuni, Webasto) intended for vehicles or RV's burn the fuel (typically diesel) with oxygen. They require and specify in their manuals fresh air for combustion. After the combustion, the new air mixture (with increased water vapor, Carbon Dioxide, CO, and un-burned hydrocarbons) are specified to be "VENTED OUTSIDE", and never inside! Note that the exhaust, just like the fresh air before combustion, contains mostly Nitrogen and Oxygen. Oxygen levels will be reduced, and some Nitrogen gets modified too.
The interior air these heaters are supposed to heat is intended and designed as a separate loop. Sometimes the manual shows "COOL AIR" or even "FRESH AIR" for this. However, this is a translation loss. If you want to heat your boat or RV, you always want the "cool air in" to be from the air you're trying to heat. So you are really using "RE-CIRCULATION AIR". This is the only safe intentional way to heat up your boat or RV efficiently using hydrocarbon fuel (diesel, gas, alcohol, propane, butane, kerosene, etcetera). Otherwise, if you use fresh outside air, your heater will need to heat it up to the temperature of your interior and interior air, and then additionally heat it to beyond your comfort temperature so you can hopefully warm your space. If the outside ambient air is cold enough, and your heater is not sufficient capacity, you may never get air that's even remotely warm enough to heat your space. Essentially, by using recirculation air, the temperature rise is smaller, more efficient, and in most situations doable - you will be able to raise the temperature with your heater. If heating outside air is better, then you might as well open the hatch or door until your interior is at least as warm as outside ambient; Only then close the doors and turn on your heater to warm above outside temperatures.
This is all done safely in a heat exchanger that intentionally separates the combustion chamber mixture from the air that you're trying to heat. This presumes a heat exchanger in good condition with no cracks or holes between the combustion chamber side and the recirculation side. Hence - the annual checks that are recommended on home and building furnaces which are rarely done! An inexpensive way to be safer and preclude disaster (and CO poisoning death) is to install and maintain a Carbon Monoxide Alarm. Carbon Monoxide alarms are readily available and inexpensive; and they include detailed use and mounting instructions. They are in every California Lowe's and Home Depot. Apartment and hotel owners are required to have them installed in every room with gas cooking or heating appliances.
Never use any hydrocarbon fuel cooking appliance, fuel heater, or space heater inside your boat, RV, home, garage, or shop to heat! Cooking appliances are assumed to produce little CO, run for short intermittent times, and usually be vented (exhaust hood) too! Fuel burning "space heaters" are actually illegal in many places, and should be illegal in all places! Lots of suppliers sell them anyhow because the government can not keep up with the policing. The suppliers can also say they are space heaters only used in open areas - means your garage with the door wide open! Maybe they're good at an outdoor Christmas tree lot if you want to stand in front of the air/exhaust mix. I personally don't want to do the garage or Christmas tree lot exercise. It isn't anything close to being a green (or even slightly intelligent) use of a finite fuel resource. In fact it's wasteful conspicuous consumption. Sweaters and Jackets are meant for this situation. The other obvious solution is a latitude/altitude with a lower number, or a hemisphere change depending on the time of year.
Even wax candles are a hydrocarbon – all the above applies!
ALWAYS REMEMBER - HEAT YOUR BREATHING AIR :encouragement:, AND VENT ALL COMBUSTION GASES :disgust:
I self installed an Ebby airtronic about 4 or 5 years ago and it is the best thing we did for comfort. It is so much nicer to go below to a warm dry cabin after a hard beat into icy wind and rain. It was easy to install and wire, and is light on the diesel and the electric. I no longer worry about it being put on as much as people want. I got mine off ebay along with all the bits required for the install.