Technical report on installation of vaccine storage refrigerator at Lungthung Health Post, East Nepal

The fridge was purchased in the United States from Sun Frost in February 1999, and tested with two Solarex 53 watt solar panels in California for a month before being air-shipped to Nepal on March 24, 1999. We flew to Kathmandu on April 2, arriving April 4 with the solar panels, regulator, wind generator, and other sundry items in our luggage. The same day, the fridge cleared Nepal customs. We purchased two batteries and three 12 volt fluorescent lamps from Lotus Energy in Kathmandu, and all items we taken by truck to the District Headquarters town of Taplejung, the end of a very long and dusty 48 hour trip from Kathmandu.

After showing the fridge to Dr U.B.Karki, District Health Officer, it was carried in its export packing crate for three days to the Lungthung Health Post. The crated fridge weighed over 200lbs, and was carried by three Sherpa porters, each taking 10 minute turns carrying, while the others steadied the load or measured bridge clearances etc. Their work was outstanding, and the fridge was unpacked, undamaged, outside the health post at Lungthung on April 11.

The health-post worker, Mr Tek Bahadur Rai, allocated a space in his already crowded 4 room health post, and we proceeded with the installation. First, a table had to be constructed to hold the fridge for eye-level access to the vaccine. Then the solar panels were installed on the roof, using slotted angle iron and through-bolts to construct a tilting frame, to which the aluminum panel mount and panels were attached. The panels were wired in parallel, and cabled to a control panel constructed of plywood under the fridge table.

Next the two Trojan "Solar Deep Cycle" 128 AH batteries, supplied "moist charged" by the manufacturer, were filled with the acid supplied by Lotus Energy. The purpose-built plastic jerry cans had been specially sealed for the trip to Lungthung, and we had more than enough acid. At this point, with the Solar Panels producing almost 8 amps, we connected the fridge to the batteries and panels, and started cooling down the fridge. By the end of the second day we had ice in the freezer, to everyone’s amazement! Also at this point, we began installing the three lamps for the health post worker’s dispensary, examination room, and bedroom.

On the third day, the Southwest Windpower Air 403 Wind Turbine was installed. A 20 foot section of 1 ½" Galvanized Iron pipe had been purchased in Kathmandu and cut in half for the journey. At Lungthung, the two halves were re-joined with a threaded coupler and erected against the south-east wall of the health post. A lot of ingenuity was required for mounting the pipe, and five straps made from split angle iron were attached to the side of the health post structure with 5/16" lag screws. A large cement base was constructed on top of the building’s foundation wall. A length of 12gauge "Romex" household cable, brought from the US, was attached to the generator, and threaded though the pipe to the base, and under the floor to the fridge control panel. At this point the generator was spinning at a useful speed, producing 2-5 amps during the windy hours around noon. Noise coupling to the structure was a problem, and in some modes, sympathetic resonances in the galvanized iron roof sent the building occupants scuttling outside to view the expected disintegration! The health post worker was grateful for the stop switch which reduced the speed of the propeller to about 60 quiet revolutions per minute.

The control panel comprises a Trace C-12 Solar Charge Regulator, a Blue Seas 12 Volt DC distribution panel with circuit breakers, a Blue Seas "State of Charge" meter, a stop switch for the wind turbine, a 12 volt "cigarette lighter" accessory outlet, and a Perko 1-2-ALL battery switch. After dressing cables, labeling the switches and familiarizing the health post worker with its operation, the job was complete in 2 ½ days on April 13. The health post worker was provided with a form to log each battery voltage and state of the solar controller on a daily basis. These forms will be recovered by subsequent visitors and returned to the US to allow the health of the system to be monitored.

Apart from checking the battery acid level monthly, and topping up with rain water when necessary, no maintenance should be required for at least two years. The batteries and wind generator have a ten-year life, and the solar cells a thirty-year life. It is unlikely the structure of the health post will survive this long!

Now that the fridge is installed, it needs to be stocked with vaccine. The desired outcome is a reduced level of new cases of rubella, polio, and childhood diseases.

We wish to express our thanks to Zambuling Treks and Expeditions (Pvt) Ltd for their crucial logistical support.

Cherie Bremer-Kamp, Research Nurse, Project Director
Rob Rowlands, Electrical Engineer, Field Director

Mr Tek Bahadur Rai, Lungthung
Kangchenjunga Conservation Area Project (KCAP), Lelep
British-Nepal Medical Trust (BNMT), Taplejung
UNICEF, Biratnagar
UNICEF, Kathmandu
Snow Lion Foundation, Kathmandu
Lotus Energy, Kathmandu
Zambuling Treks and Expeditions, Kathmandu
Sun Frost, Arcata, California USA
American Himalayan Foundation, San Francisco, California, USA