Enclosed gas stove for people with MCS
who live off-grid or are electrically sensitive
People with chemical sensitivities usually cannot use a gas stove inside a house. This is a problem if they are also electrically sensitive or live off-grid. This stove enclosure has worked great for more than five years for a man with severe MCS and EHS.
Keywords: gas stove, propane stove, enclosure, box, cooking, off grid, electrical sensitivity, chemical sensitivity, MCS
The basic setup
The owner of the house has severe chemical and electrical hypersensitivities. To escape air pollution, ground currents, cell towers, etc., he built his house in a remote area of Arizona far from the electrical grid, where he uses DC electricity from solar panels.
His only option for cooking was propane gas, but he could not use that inside the house and he did not want to cook on the porch as some in his situation do. Instead, he built a special gas kitchen with an enclosed gas stove, which has served him very well for more than five years.
The gas kitchen also has a propane refrigerator with an enclosed burner that is vented up through the roof.
The location of the gas kitchen is an important part of the house design. It is placed in the southeast corner of the house so there are two exterior walls with windows for ventilation and the prevailing wind can provide good cross ventilation. The windows are kept open much of the year since the stove and refrigerator generate a lot of heat and minute amounts of gas and exhaust may escape the enclosures. (Due to his electrical and noise sensitivities, a fan is not possible.)
The house also has a regular kitchen where food is prepared and where there is a dining area. The two kitchens are adjacent to each other and connected via a vestibule that also serves as the entrance to the house. This way there are two doors between the gas kitchen and the main house in case there is ever a gas leak.
The gas kitchen is insulated from the rest of the house to prevent heat from the kitchen from warming up the rest of the house (which has no air conditioning). The kitchen walls are well insulated and there is a thermal break between the concrete floors in the kitchen and the rest of the house.
The gas kitchen has an in-floor radiant heating system, though it is used only a little in the coldest part of the winter. The waste heat from the propane refrigerator is sufficient for most of the heating season.
The walls of the gas kitchen are sealed to prevent any gas from entering the rest of the house. The drywall is sealed with aluminum foil that is attached with wallpaper glue and then painted. The electrical outlet boxes in the walls are sealed with aluminum tape and expanding foam.
Most modern gas stoves require AC power to operate the controls and a glow bar inside the oven, but there are a few non-electric models available. The stove used here is from Peerless Premier in the United States.
The only electric part on this stove is the piezoelectric igniter, which generates a brief spark to light the burners and otherwise is totally EMF-free. Pilot lights are not used since they generate fumes all the time and not enough heat to ensure that the fumes will rise up through the vent (see later). The stove has an oven that is also lit by a piezoelectric igniter.
As originally purchased, the stove needed 110 volt AC electricity to generate these sparks. The owner simply installed a set of piezoelectric igniters that are normally used for barbecue grills.
The stove manufacturer has since started offering a 12 volt battery-powered igniter system.
The enclosure is custom built of glass, stainless steel and maple. Maple was chosen because it is the least aromatic type of wood and it does not need to be painted or sealed. Stainless steel was used because it will continue to look nice for many years, unlike aluminum or steel.
Glass is used extensively to allow the cook to monitor the pots from outside the enclosure.
Glass doors on the front allow the cook easy access to place a pot on a burner and stir a pot. The doors are made rather small to keep gasses inside the enclosure.
A door of maple and stainless steel provides access to the oven.
The doors use a silicone foam gasket to close virtually air tight. Silicone was chosen because it does not smell when warmed by the stove, whereas other gasket materials do.
The top of the enclosure is pyramid shaped to help the warm fumes rise up into the vent stack. The vent stack has no fan to avoid noise and EMF. Instead it is designed to operate by natural convection (hot air rises) through an eight-inch (20 cm) metal flue pipe that is well insulated as it passes through the unheated attic. The flue pipe is sloped to exit on the top of the roof and back from the gable to ensure little air turbulence and maximum draft.
There is an outlet for compressed air inside the stack. The compressed air can be used to start the air moving up the stack when the stove is lit, but this feature is rarely used in practice as the natural stack effect works so well.
The stove controls were extended outside the enclosure so it can be closed while igniting the gas. The knobs were extended using flexible rubber tubes and steel rods that were machined to fit the knobs. The rubber tubes are the kind sold for use as automotive fuel lines.
The design has several safety features to protect the owner from mishaps that could expose him to raw gas, contaminate his house or even cause an explosion.
As listed on the second page, the gas kitchen is sealed off from the rest of the house by airtight walls and two doors, in case there is a leak.
The gas line to the stove comes out of the ground just outside the gas kitchen wall and goes directly into the kitchen with no pipe joins inside the wall. This makes it easy to locate and repair any leaks.
Since the owner of the house leaves the gas kitchen while the food is cooking and has sometimes forgotten he has food on the stove, he has installed a timed shut-off valve that keeps the gas on for up to 60 minutes. The timer is a mechanical wind-up mechanism that operates an electric gas valve mounted behind the stove.
Most modern gas stoves have an electric glow bar inside the oven to ensure the burner is lit, but that is not possible in a low-EMF and off-grid house as the glow bar consumes 500 watts. This stove model has a non-electric system to make sure the oven is either lit or the gas is shut off. The system uses a special non-electric gas valve that shuts off if it doesnŐt sense the heat from the burner. To light the oven, a tiny burner is first lit to generate enough heat to open the gas valve. It is a very simple process.
The system has worked very well without major mishaps. The owner has forgotten food in the oven and on the stovetop in a few cases, so the food became carbonized and soot covered the inside of the glass. Amazingly enough, even in those cases, the enclosure worked so well the owner couldnŐt smell the burned food. He now uses an alarm clock to make sure he doesnŐt forget the food.