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Jim Gibson (River_rat)
Registered Member
Username: River_rat
Post Number: 125
Registered: 1-2009
Posted From: 75.95.96.192
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 25, 2009 - 10:14 pm: | |
Does anyone know the current draw for the monster 3/4hp blower motor in the 4104 main heater unit? It is not on my motor id plate and I could not find it in the book.
Thanks,
Jim |
George M. Todd (George_mc6)
Registered Member
Username: George_mc6
Post Number: 892
Registered: 8-2006
Posted From: 76.171.79.185
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 26, 2009 - 12:45 am: | |
45-50 Amps.
G |
Jim Gibson (River_rat)
Registered Member
Username: River_rat
Post Number: 126
Registered: 1-2009
Posted From: 75.95.96.192
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 26, 2009 - 3:14 pm: | |
George, It's a two speed motor - do you know if the draw on high or low? It might be low as "new" technology 12VDC Leeson 3/4HP are 58 amps at the 3/4 level and it is hard to imagine that DC motors have gotten less efficient over 50 years! Also, I wonder if the low setting is "roughly" 1/2 the high power. If so, it means a 1/2HP motor would sping the blower around the low setting, and if it were a 2 speed, might be able to run on low and thats getting into a reasonable current draw.
I'm just pondering if it might be feasable to use that house air distribution system as a evap cooler blower. It would not be hard to add a wetting pad system in that first bay behind the pass door so air is sucked into the original air system through the pad - just a thought. Running that 3/4hp on a batt bank is out of the question, but if it could be done with less, it might match the output of one of those small 1kw gennys that run forwver on a gallon of gas. My 7.5 genny uses way too much if I am away from a gas supply for too long, so just thinking of options.
Jim
Jim |
George M. Todd (George_mc6)
Registered Member
Username: George_mc6
Post Number: 893
Registered: 8-2006
Posted From: 76.171.79.185
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 27, 2009 - 10:28 am: | |
Jim.
Something we just can't get away from is 746 Watts per horsepower. When we divide 746 by 12, we get 62, and 3/4 of that is 46, theoretical perfect, at 12 volts. Amp draw will be less on low speed, because it is doing less work.
Actual amp draw may be less, because of the air flow resistance in the ductwork, and will be less if you run it on a generator at 14 Volts instead of 12.
A thought would be one of those hand-made "battery toppers" discussed here a while back. No need to make 120 VAC just to turn it into 12 VDC.
A two horsepower engine, belted to a 100 amp one wire alternator would be plenty. The pulley on the engine should be larger than the alt, so the eng doesn't have to run 'annoyingly' fast to get 50 Amps.
I would suggest trying the cooling with a pad and a garden hose in the driveway before I went to a lot of work, remembering also that it won't work at all in humid climates, and will use a LOT of water in dry ones.
HTH,
G |
Jim Gibson (River_rat)
Registered Member
Username: River_rat
Post Number: 128
Registered: 1-2009
Posted From: 75.95.96.192
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 27, 2009 - 11:13 am: | |
Thanks George - great info. Yea, there is little escape from Mother Nature and the laws she makes. Thats an interesting idea with the 12V genny idea - might keep my eye out for a little, somewhat quiet engine and alternator. I just bought a spare for my bus but its a bit large! I seem to remember reading they were over 200 amps - not a surpric=se with this big old motor they ran.
I live in Northern Nevada and it is really dry so evep is very good, almost better than compressor air because it puts some moisture in the air. Normal evaps do use a lot of water and thats part of my dilema, but I think because the bus is so small, I might be able to rig something efficient. I have a small 2700 cfm unit in my house - about the smallest normal window unit - and it almost cools 2000 feet of house. That unit in a bus would be freezing, so I figured I would eliminate the two side pads, and meter the water on the one remaining pad. I wouldn't be surprised if used 10-12 gallons/hr in its "normal" mode, but I am thinking that I might be able to cut that to 2-4 gallons or so and still keep the bus cool. I am putting a 100 gallon extra tank under my bed and it would be a good use for some of that water. The other reason for thinking of this is that I would put good filters in front of the cooler pads and keep a positive pressure in the bus with a reasonable filteres air supply. Just thinking through it, and I appreciate your help and thoughts.
I am really loving this bussin' thing - it's like having a small house and trying to make it livable and efficient is a real challange.
Thanks again!
Jim |
doug yes (Dougg)
Registered Member
Username: Dougg
Post Number: 93
Registered: 1-2007
Posted From: 68.252.42.193
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 27, 2009 - 3:10 pm: | |
Jim, Why not try some mister nozzels? You can spec the exact gallons per hour depending on the nozzels you use. |
Jim Gibson (River_rat)
Registered Member
Username: River_rat
Post Number: 130
Registered: 1-2009
Posted From: 75.95.96.192
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, June 28, 2009 - 11:13 pm: | |
Good idea. I think they use somewhere around 1 gal/hr for the little ones, so pointing a few at a pad in the air stream would - migh - make a little bus size cooler with a controlled water usage. I think I might just try it!
Jim |
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