Category Archives: Toyota Dolphin

Thoughts on solar powered air conditioning for the Dolphin

I have been pondering the ac and solar system in the Toyota motorhome. Mental exercise at this point. I first thought about a window unit ala Pleasure Ways  and Roadtreks.  The idea is to have the batteries be able to power the rear ac going down the road. The problem is that air conditioners are energy pigs.

The small size of the dolphin has an advantage over the bigger motorhomes. I do plan to gut the entire box and rebuild from scratch. Giving this project another advantage. We can tighten up the envelope. We can insulate properly.  Get rid of large windows. Great for views but horrible insulation properties. R1 at best.  Most heat is lost through windows and doors. Then the ceilings. If you are going to need to park it in full sun. Better have a well insulated roof.

After looking at specs for 9000 watt units. Muddling through  ratings, Can’t  manufacture use the same formulas for all units? Anyway, I quickly came to the conclusion that window units used too much power even for the low cost. I did not consider downgrading to a 5000 btu unit. It was not going to cool us down except for a 80 deg night and I want this unit to keep us cool traveling down the interstate without a generator .

I am familiar with mini split systems. The run the spectrum from piece of shit to this might work. The important part here is SEER Rating. The higher the number the less amps or watts it pulls. I am not going to factor in inverter loses. Simply the SEER Rating is a ratio between the watts per hour and the BTU rating. I have found units from 13 seer to 27 seer in 9000 btu models.

lets do the math on the 13 SEER model first. 9000/13 equals 692 watts. Divide the 692 by 12 volts ( our battery working voltage) we get roughly 58 amps out of our batteries. Actually more amps are used because of inverter inefficiency. Working with 220 usable amp hours of  batteries,  3 hours will drain batteries without a charge.

When we check out the 27 SEER unit. 9000/22 equals 333 watts and by 12 we get 28 amps an hour out of our bank. Twice as efficient as the 13 SEER.  6 hours easy . That means on a sunny day 400 watts of panels can keep up with this load. The panel manufactures fib a bit on output .  Add 15 percent to your calculations to cover them. 9000/12 equals 33 amps .In the real world figure 26 -28 amps. Pretty sure a heavy duty alternator is capable of keeping up with that going down the road. May need to upgrade some extra components in the charging system. Relays etc.

The down side is this arrangement is two times the cost of the 13 SEER. You get what you pay for!

Another great feature is the ability to run them on smaller inverters. The larger inverters have higher standby losses. We don’t plan on a microwave so the ac would be the heaviest load on the system. A decent pure sine brand in the 1500 watt range , Samlex or equal.

I was going to upgrade the alternator to a heavy duty high output model. Still researching the charge controller from the alternator and the panels. I need a smart charger that can monitor the batteries and handle the ac load as well as a heavy charge rate from the alternator.

 

The added bonus is we get a heat pump with this package. I was looking at a diesel cab heater for the heat . Open flame heaters really don’t belong in a RV anyway. Another rant another evening.

i would love to hear feedback on this.

 

 

 

1983 Toyota Dolphin rebuild

toyota

1983 Toyota Dolphin

We picked up an older dolphin on a stair railing trade out. We had it towed out of the yard. The pieces to the engine were on the table in pieces. I did get it running after a trip to the wrecking yard. The carb was in tiny pieces, much like a jig saw puzzle.

We have been driving it around town now all spring. It gets around 16 – 18 mpg. Not bad for its size. I have been surprised at its handling abilities and we did get it up To 66 miles an hour on flat highway.

After months of analyzing the thing I decided to dump a boatload of cash into the project. Mechanically the thing is sound. It has the full floater rear end installed per recall. Without it the thing is unsafe to drive. Lives were lost  in the past from axles coming loose at speed. Toyota did supply owners with new factory axels to remedy the problem. Toyota also stopped the sale of the trucks for motorhome conversions.

The previous owner had replaced the roof completely. The walls have rot below the windows. The walls have a minimum of insulation. The roof seems to have 3/4 styrofoam. The exterior walls are Mesa design aluminum siding. That has seen its share of hail storms over the years.I pondered replacing the exterior walls and residing the thing. I have a local company that can make the siding, the cost was reasonable. In the end I figured for the amount of work I could replace the whole box and have a layout my wife and I want.

The existing layout had a rear side door with a kitchen and tiny wet bath in the very back. The bath was hardly usable for anyone over 5 ft tall. The bed over the cab was 4 ft wide. Not large enough for two adults. The lounge seats were uncomfortable with thin foam.  Someone had scavenged the water tank, heater, and barrel seats before we got it. The floor is 3/4 plywood that had settled over the years. Not really much to base a rebuild on so it will come off as well.

Next week we will be tearing this thing to the cab and frame. The advantages are numerous. The ability to inspect the frame. Acces to brake lines. Shocks. Water gray tanks etc.

We are making changes to the layout. Installing a double bed in the rear higher off the floor for extra storage underneath. Relocating the door to the front. Relocating the bath to behind the driver. Utilizing a sunken shower floor in the hall like the old pleasure ways used. I am not using a black tank. But going with a cartridge system. Keeping my gray tanks cleaner and better smelling.

The propane fridge is being dumped in favor of an Engels 12 volt chest. We will also build in a chest cooler in the kitchen counter like boats use. The engel will be setup as a freezer supplying frozen blocks for the cooler. I am wanting to rid the camper of propane. I will install a single burner induction burner for cooking inside. Most of our cooking will be outside anyway.

I plan to construct the walls with 1 1/2 inch pink foam with a 11/2 hardwood studs. I will attach 1/4 inch luan to both sides the outside will get a filon covering. The inside will get a heavy wall paper. The ceiling will get the same framing except I will use the white board ceiling and a rubber roof.

i plan to install a house window ac on the back wall. I want to keep the roof clear for solar panels and a kayak rack. I will have a fantastic fan above the shower area.

The solar system will consist of 400 ah AGM batteries and 400 to 600 watt panels on a tilt frame.  A 30 amp mppt controler and a 2000 watt pure sine inverter. This gives us a little under 200 ah of power daily. Enough to run the cooktop, lights, led of course, TV, computers,engel freezer, phones…..the truck alternator will also be used to keep us topped off.

Stay tuned