| Author |
Message |
Eric Plourde
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 16, 2004 - 1:43 am: | |
It is finally going to happen. With only the woodstove for months we are finally going to have heat!
I have read all the old postings on The Board about installing a Webasto and am looking for other pointers and such. All of the should have, could have, would have, ooooppppsssss stories.
My basic plan is to tie it into the engine heat lines with a bypass. Running as much baseboard heat as possible (20+ ft.). With one kick heater in the old intake for the AC at the front, and about 10 ft. in the bedroom area for baseboard. I am planning on an expansion tank seperate of the radiator and running all the baseboard off in parallel to the back.
So, I would love other hints and plans.
Eric
Cowboy Game
PD4106 |
FAST FRED
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 16, 2004 - 5:20 am: | |
Baseboard does not give too many Btu per foot (mostly depends on the temp of the circ water.
You might wish to see if 20 ft is enough , a simple U turn could doubble the run.
This is great SILENT heat ! so is worth the effort.
FAST FRED |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 16, 2004 - 12:35 pm: | |
If you are tying it into the engine coolant system, then the radiator is your expansion tank. At least it was on mine. Make sure it is plumbed into the defroster/driver area heater system.
Richard |
Eric Plourde
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 16, 2004 - 6:36 pm: | |
I am wanting to isolate the engine for the winter. We are full timers and need this heat all winter. Can I use a regular expansion tank from a plumbing supply store?
I found a BTU estimate formula someplace in the old files but is there an effective way to figure out BTU needs while living in it?
Circulation pump I am looking at is around 20 gal. a min. How much is the effect of 90 degree 3/4 copper fittings on the flow rate.
Thanks,
Eric |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 16, 2004 - 10:04 pm: | |
Hello Eric.
I'm heading in a similiar direction.
A few ideas:
The existing engine and radiator overflow/expansion tank can act as your pressure tank if you effect your circuit isolation by closing off only one line to the engine - ie: there won't be flow without a return, but the pressure and expansion can go down the single line.
I agree that as a full timer, you do not want to be heating anything unnecce$$arily!
You may want to have a circuit designed that puts hot water through a heat exchanger which has a fan in it. The baseboards will be good at keeping you warm, they will be horribly slow or impossible for warming up a cold coach, or for dealing with really low temperatures.
For instance, my coach is currently set up to allow the hot water to flow through the stock coach heat exchanger, and the big stock fans may be turned on independent of running the engine. Also, the defroster in the front end may also be set up to provide fan forced hot air.
These two stock adaptations are not the best for extended economical use, as both of these introduce a lot of outside air, which requires heating, and there needs to be a source of power to keep those big fans running. It would be less expensive/more efficient to use a fan unit which uses an interior fed air supply, and smaller fan motors. I am not fulltiming, so the loss of efficiency is not critical to my current style of use.
I'll be adding the baseboard circuits to enjoy the silence, and the ability to stay warm all night without listening to fans or engines.
For more silence, you will want to consider a way to sound insulate the Webasto, and the coolant pump. The Webasto does make a certain amount of noise, and if yours is quiet now, it will make more later, as the bearings get older.
Taking a page from residential boiler systems, adding in a few high spots in the plumbing to capture air, and a way to bleed the air out, will help keep the gurgling to a minimum.
You will also want to consider locating your Webasto low in the system, to ensure that it always stays completely full of coolant. And install the big shut off valves in the coolant lines, so you can remove or work on it without draining all the coolant. Also, install stut off valves in the fuel supply and return, for the same reason. A marine-style fuel primer bulb also lends some piece of mind when trying to get a unit that has been serviced re-started.
Do the annual maintenance on your Webasto, and pay the money for legitimate Webasto parts. You have to remove the head for this, hence the fuel valve advice.
Also, where is your Webasto exhaust going to go? And where will it go if the wind is blowing the wrong way? The exhaust is unpleasant smelling to most and potentially poisonous. Be careful with length of pipe run and diameter. Webastos require a carefully set amount of air (that adjustable closure in the intake - See the manual for details)
And, what size Webasto are you considering? They come in a variety of burner sizes, some fairly small, perhaps inadequate to warm up a cold coach interior, (40 000 btu) others with the power of a small home furnace (+100 000 btu).
Be careful, many dealers have only dealt with the smaller ones and haven't heard of the big ones.
Good luck, and be sure to report on your progress!
happy coaching!
buswarrior |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 17, 2004 - 9:50 pm: | |
Eric, I don't think the 20 gpm of the pump will be much of an issue in your setup. At 20 gpm, I calculate a 4.5 degree temperature drop in the circulated water will take all of your 40,000 btu from an RV sized unit.
Some numbers I recall from installing hot water baseboard heating are 810 btu/foot for 100 degree rise. That's about 6500 btu per 8 foot unit or 24,000 btu for 30 feet.
It seems to me that you will need more radiating capacity to soak up what a 40,000 btu boiler will put out. And you will need to know if you will need more than 40,000 btu to heat your coach in the weather that you're going to be using it in.
Many coaches use a couple of furnaces in the 30 to 40,000 btu range. So, I would think that you're going to want to do some real world testing to find out how much you will need.
For experimenting purposes, a 1,500 watt electric heater is real handy because they put out right at 5,000 btu. You will need 6 to 8 of these to equal one furnace, depending on their ratings.
Also, you won't be likely to get more than 100,000 btu out of a gallon of fuel oil, so you need to allow for that.
When starting a hot water system up in a cold coach, you need to allow for the time it will take to heat all the water that you are circulating in order to get to full heat output. This is a major area where systems are underdesigned.
This may be one of those cases where you want to measure twice and cut once!
Tom Caffrey PD4106-2576
Suncatcher |
Eric Plourde
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 18, 2004 - 10:46 pm: | |
It appears that I have purchased a DBW 300 Webasto heater. Looking it up it runs about 104,000 Btu's. I was a little worried after the post but I think I shall survive the Utah cold!
I have another thought though. In talking with my father he asked how I would be putting pressure to the system. My 4106 does not have a radiator cap for pressure. So how do you create the needed bar in the system?
Eric
4106 |
Eric Plourde
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 18, 2004 - 10:47 pm: | |
Oh also, he has another 300 as well to sell. He gave me a bit of a deal for work trade but I think he is looking for $2000.00 each but don't quote me on that. Email me for more info.
Eric
4106 |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 19, 2004 - 12:19 am: | |
Hello Eric.
Same as mine, the 300 model. You won't be disappointed with the BTU!!!
You don't need any pressure. Plumb it in where it will stay full of coolant, and fire it up!
happy coaching!
buswarrior |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 19, 2004 - 7:51 am: | |
A basic rule for heat and A/C systems is that they should run 100% of the time in the most extreme temperature you will encounter. A Webasto 40k BTU will keep a bus warm at 0*F if you have good insulation and a minimum of good windows.
When it is colder than that you are just surviving in an RV of any type. Even in the best insulated houses the interior walls are cold. The small confines of an RV mean that you are always sitting or sleeping close to a wall which is sucking the heat out of your body. BTDT many times while trying to get from the fridgid North to the warm South. With a well designed bus, at least you don't have frozen water and waste tanks like the production RVs.
I think a 103K BTU is much too large as I know one bus owner who removed an 80K in favor of a 40K because of unsatisfactory operation. |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 19, 2004 - 9:30 am: | |
Stan,
He could expand radiant heating into the walls with the 103K BTU and conceal the heat loss!
But I wouldn't want to pay his fuel bill!
FF's recommended quilted shades, slippers and a house coat might be less convenient but more practical! Maybe even Jammies! |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 19, 2004 - 2:58 pm: | |
With a proper sized boiler the flame comes on and heats the water: the circulation pumps moves the water through the system: when the room temperature reaches the room thermostat setting, the flame turns off but he water continues to circulate. The water is cooling down as the room temperature drops to the thermostat turn-on point (about 2* below turn-off) and the flame cycle starts again. When the outdoor temperature is at the design point of the system the circulation pump never turns off.
With an oversize boiler, the water temperature rises so rapidly that it trips the overheat switch on the boiler. The pump then circulates this overheated water but the flame will not come on until the overheat switch has cooled down enough to reset. This results in large temperature swings and very poor heating.
A Webasto is essentially a flash boiler and there is no large volume of water to absorb and hold heat. You have to get rid of the heat as fast as it is put into the water. On two busses I used forty feet of 3/4" with 2" fin and a design factor of 900 BTU per foot. In order to find room for 40' I doubled the line on each side of the living room with single lines in the bedroom. Only drawback was that the room temperature would drop for the 30 minutes it took to preheat the engine on a cold morning. |
bruce king
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 19, 2004 - 6:23 pm: | |
Stan, did you put in a seperate liquid route for the coach heat, or did you use the bus coolant?
if you used the bus coolant, what did you do to stop the fluid from running through the radiators?
Here's what I'm trying to figure out; in order to heat the core, I think I have to have coolant going through the radiators, which'll mean a large heat loss. |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 19, 2004 - 9:36 pm: | |
Bruce: To take your last sentence first, the bus radiator has nothing to do with pre-heating the engine or heating the bus interior. Engine coolant lines come off the block, one on the bottom rear with a manual valve and one on the top right with an electric valve.
When you say "heat the core" I am assuming that you are leaving in the bus heat. If so, then you have to leave the electric valve for the bus heat system to work properly. If you are not leaving the bus heat in place, then replace the electric valve with a manual valve and install a normally closed electric valve in the loop of interior heat that you are installing. This valve is controlled by the house thermostat that also supplies power to the Webasto burner through a relay.
Note that the original bus electric valve is normally open and uses a lot of power to keep it closed.
Operation:
In summer at least one valve to engine block closed and house thermostat turned off when driving or when parked.
In winter for Webasto heat parked, one engine valve closed and one open to allow expansion to rad. House thermostat turned to required temperature. To pre-heat engine open both valves to engine block.
In winter when driving if you have original bus heat just turn off the house thermostat and open both engine valves. If you don't have bus heat, open both engine valves, set thermostat and turn off power to Webasto so that only the electric valve is controlled by the house thermostat.
Note that the valve controlled by the house thermostat is in the loop going around the bus to whatever type of radiators you use so that it will stop the circulation only to those radiators. The lines to the driver's heater/defroster get water from the system unless the valve beside the driver's seat is closed. It is not even necessary to use this valve because the heater core does not produce any usable heat unless the fans are running. |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 19, 2004 - 10:32 pm: | |
Stan, I think your description of the boiler operation is missing one control, and it makes a difference in planning the hookup.
That is the aquastat that controls burner operation to maintain boiler temperature. With an aquastat, the room thermostat only controls the circulator, not the burner.
If the circulator comes on to warm a room, the boiler temperature falls and the aquastat turns on the burner to bring the boiler back up to temperature.
The high temperature cutout is used as a backup, in case the boiler temperature rises too far about the aquastat setting, as it could if the aquastat failed.
Some designs cut off power to both burner and circulator if the high temperature cutout is tripped. This may be to draw your attention to the fact there is a control problem that needs attention.
If a high temperature cutout only shuts off the burner, the unit would continue operating pretty much normally until something else happened to go wrong.
One thing that has to be done on setting up these boilers is picking the right aquastat setting so that you don't trip the overheat cutoff. If that isn't done right, you get the kind of symptoms that you described above.
If you find out that those heaters don't use an aquastat, please post it here. It will make a difference when we set up our Webasto.
Thanks.
Tom Caffrey PD4106-2576
Suncatcher |
john wood
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 20, 2004 - 2:20 am: | |
Typical residential baseboard is generally rated at about 500 or so BTU per linear foot at a 20F Delta T and at 180F operating temp.
Works out to about 1 gpm per 10,000 btu of output. To disperse 100,000 BTU, you need approximately 50 feet of standard residential baseboard and 10 gpm. Watch the head loss!! |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 20, 2004 - 9:33 am: | |
Tom: The standard 40K Webasto heaters that I used did not come with an Aquastat. They used snap type switches for operate and overheat and then a meltable fuse inside the water jacket in case of coolant loss. I am familiar with aquastats on home heating boilers but I don't know if they would work on the small volume of water in a flash type boiler. The original use for a Webasto was engine pre-heaters and in that scenario when the manual or clocked switch turned on supply voltage, the burner and circulator ran continuously until the engine reached the operate switch temperature (185*F ?). In artic communities they are used to keep large (1000 kw) standby plants warm all winter. To use it as a house heating boiler you have to control the boiler and circulator separately as you do in a house heating system.
John: No argument with your calculation but the baseboard fin I used was specified by the manufacturer (name long since forgotten) as 900 BTU per foot. It was a high density directional flow fin (air could only move in the vertical direction with the finning closed on the front and rear).
I am not a heating engineer so I just used the fin manufacturers data to match up with the Webasto numbers for boiler and pump. Personally, I think the Webasto is a very poor unit for this application but it appears to be the best available at a price affordable by most home converters. Using the Webasto in the 'Aquahot" system heating a large volume of water 24/7 is much better but at considerable fuel cost. |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 20, 2004 - 11:30 pm: | |
Stan, I think the snap type switches for operation and overheat cover what I am talking about. The operation one should serve as the aquastat.
In any case, I will be on the lookout for this in our unit.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher |
Eric Plourde
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 21, 2004 - 12:10 am: | |
A question on pipe size, the 300 and pump have outputs of 1 inch. I was thinking of using the old heater lines in the couch are 3/4. Do I need to replumb this at 1 inch.
Also it appears the Webasto begins heating at 140 degrees and then shuts off at a higher temp. (can't find that number now). This would seem to be that is is running on a aquastat. I am putting in a coolant pump since the orig. pump is staying in the bus it came out of. So my thermostats will be hooked to the circulator? If that is the method then how do you keep the Webasto from coming on without the circulator running.
This may all fix itself after I look at the docs. with it. And on that note anyone have a DBW300 instalation info. or a place to find it?
Eric
Cowboy Game
4106 |
Eric Plourde
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 21, 2004 - 12:49 am: | |
One more thing, for now at least. I keep reading that the water pump needs to be about 20 GPM. But home baseboards require around 4 GPM or there is noise from the water circulation.
Also since I am here. Running the baseboards in series means alot of T's in the system. Will water be forced through the baseboard if the main line is a circuit.
And what about taking the last bit of heat out by weaving a pattern around the bottom of the tile bathroom floor to heat up the toes.
So many ideas. I thank everyone for the help.
Eric |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 21, 2004 - 4:55 am: | |
Eric,
I understood (but haven't had to deal with it myself, yet) that careful installation and thorough bleeding of air from a closed Webasto system would take the "gurgle" out.
Getting the air out of an "open" engine based system is complicated and detailed but effective. To explain further, the narrative I obtained from an auto engineer with extensive cooling system experience is quite lengthly and should be polished and put into an article.
FF, I thought, speaks of convective flow with baseboards, but I don't know exactly how he achieves it. Designing it into your system would help the pump, maybe.
Marc |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 21, 2004 - 8:20 am: | |
Eric: As I pointed out in a previous post, you are installing a boiler with enough capacity to heat a three bedroom house in the high artic and may run into a lot of problems. You have to remove the heat as fast as it it generated in the boiler or it will overheat. To take 40K BTUs (or less in anything less than extreme cold) from your boiler will have the burner trying to go through a startup and shutdown cycle every minute or two. These cycles are not instantaneous. The firebox has to be purged before starting and the boiler has to be cooled down before stopping.
That said, if this is what you want , there are two distinct methods of piping. Regardless of how many zones you use, you either run all the radiators (baseboards) in series or you run them in parallel using a restrictor tee at each one. Either method requires careful calculation of heat loss in each area for the proper selection of restrictor or length of baseboard.
Like many things on a do-it-yourself conversion, a lot of research is required before you start.
Marc: Even with no air in the lines, the fins amplify the sound of the water flowing in the pipe. The higher the flow rate, the greater the noise. I installed a hot water sytem in my house with ethylene-glycol mix for coolant and a air extractor on the system. After twenty years, you could still hear the water flow. This is strictly for information because the sound made by the water is so small compared to the noise from a hot air fan system. |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 21, 2004 - 8:10 pm: | |
Can't these larger capacity boilers be fired with a smaller nozzle, adjusted to suit the demands made on it?
That's what we would do with a household boiler to prevent rapid cycling. I'm not familiear enough with them to know if there is some requirement to fire them at their maximum rate.
Good luck, Eric.
Tom Caffrey PD4106-2576
Suncatcher |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 21, 2004 - 9:01 pm: | |
Anything is possible but is it practical? The Webasto is a forced draft boiler with the combustion air fan and fuel pump driven by the same motor. Air mixture is critical so you would have to find some way to reduce the air to match the smaller nozzle and some way to slow down the high pressure fuel pump.
If you accomplished these things I don't know if the flame would carry the length of the boiler. The flame has to travel inside the liner the full length and then return around the outside of the liner in contact with the water jacket. It would be a pretty complicated system to modify. |
Bruce Henderson (Oonrahnjay)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 21, 2004 - 10:16 pm: | |
__. Stan, thanks for the tip-top level of advice and experience that you're sharing here, but one idea just jumps out at me. Could the output of the Webasto go into a "plenum" (a tank of say two or more gallons) that's circulated (and I'd guess also thermosyphoned) to keep the heat exchange going in the Webasto and then an additional circuit off the plenum to provide the hot water into the radiation appliances -- all this in parallel, not separated by heat exchangers, etc? For not much more complication than a tank and one extra pump, you'd cover most heat exchange needs out of the Webasto, I'd think.
__. Just a thought ... I don't have any experience with these things in this application.
Thanks, Bruce Henderson, Wallace NC, USA |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 22, 2004 - 3:21 am: | |
To match the capacity of a 103K BTU unit, I'd wonder if the size of the lines sufficient to distribute that much heat, by the thermosyphon technique alone, would have enough volume serve as your reservoir? |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 22, 2004 - 9:07 am: | |
Bruce: That is a feasible solution if the tank is large enough. Aquahot uses this system whereby they keep a tank of coolant hot 24/7 so that instant room heat or constant domestic hot water (from a heat exchanger) is available. The drawback is high fuel consumption keeping the tank hot or else the delay in getting room heat if the tank has to start from cold.
Thousands of conversions and passenger coaches (with four stroke engines running in cold climate) use the 40K Webasto in a simple system tied into the engine coolant system. With a few valves, which can be electric or manual, you can preheat the engine or the interior with a proven system. Why re-invent the wheel? If someone gave me a 103K unit to put in my bus, I would just try and find someone who had a use for that size and trade for a 40K. |
Bruce Henderson (Oonrahnjay)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 22, 2004 - 11:44 am: | |
Stan (very logically) said:
"Why re-invent the wheel? "
__. That ranks right up there with "Keep It Simple" as the best advice.
Thanks, B |
john wood
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 24, 2004 - 5:21 pm: | |
Bruce;
Your "plenum" is called a buffer tank in the industry. To estimate the run cycle, figure that one BTU will increase the temperature of one pound of water by one degree F. 20 gallons with 140-180 gives 40F for 40BTU times the 20 gallons at approx 7 lbs per gallon, 140 lbs and will "take on" 5,600 BTU's in one hour, or give a run time of approx 18 minutes for the boiler. This without the external load from whatever the heat emission device you use. If you used an indirect water heater tank for the buffer, you then would have the domestic hot water as well from the same source with no additional equipment or space. |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 25, 2004 - 12:12 am: | |
Hello Webasto fans.
That DBW 300 model, with it's 100 000 BTU output, is used extensively in stock applications, both highway and transit buses, quite adequately.
The aftermarket one in my MC8 works just fine, feeding the stock heat exchanger and then being fan forced to the coach. I have all my stock double pane windows, which is good for some BTU consumption.
Depending on your uses, a 40 000 BTU unit won't keep you warm in the winter, and if it is able to warm up a cold bus, it will take an uncomfortably long time doing it.
Careful gentlmen: How long will she want to wait for your "engineering" to warm up the coach?
If you aren't going anywhere cold, I'd reconsider using a hot water system; you may sweat no matter what heat plant you use.
I doubt any of you would advocate using one roof air to stay cool in Arizona in the summer time, and would recognize the impossible task of cooling down a hot bus with only one under those conditions. Heating works in a similiar way, only worse, because the change in temperature needed is greater. 110 to 70 is 40 degrees of drop, 0 to 70 is 70 degrees to raise. And we all know that 30 000 BTU of cooling is going to struggle with that 40 degree pull down. How will 40 000 BTU make it pushing 70 degrees?
A glimmer of cool air, while the AC struggles, makes us feel better when its hot, you will not achieve the same marginal benefit when you are cold. A little warm breeze in a cold bus doesn't cut it, if your toes are cold!
For Arizona, some will say there's no such thing as too much air conditioning.... For the northern states, Alaska and Canada, there's no such thing as too much heating, if you know what I mean!
The Webasto, if installed and wired properly, regulates itself. In my install, it gets up to temp, and the burner shuts off. Shortly, once the temp inside the unit is cool enough, the circ pump shuts down. The modern buses work the same way. The little control box, size of two cigarette packs, costs upwards of US$400 for a reason.
If you are going to run radiators, and isolate the engine circuit for economical operation, the choice is yours whether to use two circ pumps and a buffer tank loop, one circ for the Webasto, one for the room thermostat to control the flow in the rads; or just the Webasto circ and a bypass loop with solenoid valves controlled by the room thermostat.
happy coaching!
buswarrior |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 25, 2004 - 9:31 am: | |
As I have frequently said on this board that I only tell what I have personal experience with. I have spent more than twenty years as a snowbird (six months in Edmonton, Alberta and six months in south Texas or Yuma, Arizona. All three busses that I converted had professionally sprayed foam insulation in walls, roof and floor. I reduced the windows to a minimum and used double pane windows and some kind of insulating shades.
I removed the original heating and A/C system except for the driver's heat-defroster and tied a car compressor to the driver's A/C evaporator (if the bus had one). Heat was provided by baseboard type radiators from the engine when driving and 40K Webasto when parked. A/C was one 13.5K roof A/C.
We spent lots of nights in below 0*F in the north and lots of days in 100*+ in Arizona. We never had a problem with maintaining the temperaure at a comfortable level except when driving into the sun on a hot day with just the driver's A/C on. When stopping for lunch, I started the genset and in a few minutes the living area would be comfortable.
Having said that, I have also pointed out that in either -40 or +100 you don't "live" in an RV, you just survive until the weather improves or you move to a better climate.
Prior to going full time in a bus we lived in a conventional house built in the 1960s that had baseboard heat from a 66K BTU boiler that kept the house warm in -40*. |
FAST FRED
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 25, 2004 - 12:44 pm: | |
110 to 70 is 40 degrees of drop, 0 to 70 is 70 degrees to raise. And we all know that 30 000 BTU of cooling is going to struggle with that 40 degree pull down.
But there are folks with dark or dirty roofs that run closer to 135F, and really NEED lots of air cond. Or a paint brush.
Heat loss thru the floor is the hardest to live with as cold feet are very disagreeable.
Simplest solution is a bunch of rug on the floor , with top layer being bathroom rug.
The bath stuff can be comercially washed once or twice a really muddy winter for a morale boost.
FAST FRED |
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