One of the great modern conveniences we have is natural gas to heat our homes and water. This is not going to be an argument if you have an “All-Electric Home” or the benefits, but simply information about what does exist. Natural gas in structures.
A good thing to do at least once in your life at every property you live in is to compare the size of the gas meter to the total possible volume of gas-fired appliances on the property. Remember, this gas meter will also have to feed things on the outside of the house including barbecues and pool heaters.
Converting a gas meter on the side of the house that has a label in CFH (cubic feet per hour) to the appliances on the property that are sized by the BTU input, is not an exact cross over. For the sake of simplification we will simply say that the conversion is 1:10. So a 200 CFH meter provides 200,000 BTUs for appliances to use. The actuality is that it will be a little more than 200,000 BTUs but then we also can get into calculating how far away from the meter does it have to travel and that larger pipes can allow more gas, etc. So again, to start this topic, let’s keep it simple.
The gas company has to provide gas several miles from the main reservoir that the city or utility company controls. These pipes under the streets etc. are pressurized and can be as high as 60 psi, often around 40 psi on the “City” side of the gas meter. Still the pressure can be as low as 10 psi when it reaches your house. Every Municipality can have their own rules and regulations as well as the physical properties of providing the gas miles down the road to the end of the line of houses or farm. That gas meter will actually reduce the pressure further and throttle it down to approximately 1/2 or 1 or 2 PSI after the meter going to the pipes in the house. Commercial units can be a little different with very large boilers, ovens and specialty equipment. The safety factor with reducing the pressure is so that houses don’t explode with regularity. Since all of us like that idea let’s not argue about this but continue on with the examples. Everyone reading this has grown up with this same pressure so you don’t need to try and ask why and change the world.
This is an example of when the size of the gas meter is too small. Let’s start with the size the central heater that is 75,000 BTUs, the gas stove/oven is 50,000 BTUs, the dryer is 40,000, the water heater is 40,000, the fireplace is 35,000 BTUs and all the interior appliances are approximately the maximum (240,000) capacity of the current gas meter that is 250 CFH (cubic feet per hour).
Now what changes happen over the 20, 50 or 70 years that the house has stood there? Someone adds an exterior BBQ outside the kitchen and connects to the stove gas line adding another 50,000 BTUs. Then the family added a pool and the pool heater alone is another 400,000 BTUs. One of the current improvements that makes a lot of sense is to install a tankless water heater! This new type of appliance must heat water instantly and does not have a tank that has been cooking over a slow fire pot with only 40,000 BTUs. The new tankless water heaters can be 160,000 to over 200,000 BTUs alone. That can be five times the size of the original water heater and this same newfangled appliance can take all the gas in the house of the original sized meter. Nothing was done wrong, the gas meter is simply too small for a newer, modern appliance that needs more gas.
So what could happen? Nothing will blow up. What will happen is that on cold winter days it will appear that the heater does not warm the house as well as it should while you’re doing the laundry that takes hot water and the dryer is going and someone is taking a shower. Besides that, it is Thanksgiving and the turkey is in the oven. So the turkey will not cook as fast and you will not get as much hot water as you wanted and the house will not warm-up as you want during the snowstorm before company comes over. So to avoid Mama running into her bedroom crying saying the turkey is still cold, not cooked and the dishtowels still have not come out of the dryer, get a bigger gas meter.
Gas Meter and Lines
Some cities are now requiring an automatic shut-off device on gas meters. During seismic activity, this turns off the gas to the house in case any gas-fired appliances were damaged or came loose, etc.
To correctly install a seismic device it must be secured to the structure. Any heavy vibration difference between the structure and the meter will turn it off. Yes, heavy trucks have been known to disrupt some of the early models of this device.
This is another type of seismic gas shut-off valve. Still just a glorified SS ball bearing covering a hole in the pipe when it shakes.
This is a newer seismic shut-off valve for a gas meter. Just different but does the same thing.
This shows a poor installation. The large pipe is on the property side to provide a lot of gas and the plumber connected it to a tiny pipe that defeats getting a large meter.
This is silly because of the tiny connectors to the larger pipes will still restrict the flow to a 3/4 inch pipe and not the large 2 inch pipe. For not spending $20 or $30 this was a poor installation and most likely the plumber, not the home owner's choice.
You are not allowed to attache two gas flex lines together. You are supposed to hard pipe within 6 feet of any appliance and only use a single flexible line.
Many older homes had individual room heaters in bedrooms and bathrooms. The gas pipes that remain can be capped in the crawlspace if you want to have freedom to put furniture close to the wall, etc.
This is one of the old style room heaters. Open flames and poor exhaust created too many hazards and these were usually replaced with gravity heaters and then central heaters, etc.
All hard pipe gas lines are actually supposed to be secured within 12 inches of the end. That is to prevent yanking on pipes and weakening joints.
A modern setup in this house uses a central manifold with large piping to this location. Individual lines for each appliance allows working on any individual appliance without disturbing the entire house. But this still has a mistake.
Notice this manifold has a separate valve for each appliance is a better installation of the manifold.
This shows an old gas valve with a newer, large capacity water heater. Not only is the old valve difficult to close/turn in emergencies, how would you reach this and have enough hand strength to close it?
When installing a flex line, this person damaged and kinked the line. This needs to be replaced to provide full flow as designed.
A sediment trap is required by more manufacturer's. This is a small "T" in the piping to catch any dirt, sand, ice crystals in winter that can clog a small appliance orifice.
Adding an electrical bond wire to all piping is generally required by most cities to maintain continuity in any ground connection. The internal parts of any appliance with different components cannot guarantee no disruption the metals for a proper ground.
Technically a union in a gas line is supposed to be accessible. The rules do not want unions in the crawlspace.
All gas lines are supposed to be at least 6 inches above the soil. This is what the moisture in the dirt will do, rust the pipe until it fails.
This is a gas line under a house in the dirt that I did not want to touch for fear it would start leaking right then.
All gas lines in the ground have to be properly protected from corrosion. Going to the garage for laundry or the pool, when you see this much corrosion the pipe section or more needs to be replaced.
This shows a gas line in concrete by a pool heater. The heavy corrosion could be worse underground and already leaking.
Gas meters come in many sizes from 175 CFH on up. A 400 is usually put in when a pool is installed but technically is still too small. Pool heaters are mostly 400,000 BTUs so how would you use any other gas appliances at the same time?
A few years back before the rotary meters, as the volume capacity for factories or restaurants, etc. increased, the meters of this volume had to be quite large to get the very large volumes needed.
There are now rotary gas meters that are now used for restaurants and larger homes and estates and factories. Also notice that this has a larger pipe to allow a large volume of gas. If you have a tiny 1/2" pipe not much gas can flow through the meter anyway.
This shows a rotary meter providing 1500 CFH, or 1,500,000 BTUs for all the gas-fired appliances.
It is recommended that the Gas Utility Company be contacted to conduct a free “Appliance Survey”. This will basically add up and total all the gas demand needs for all the appliances on the property and calculate the appropriate sized meter. Having a larger meter does not necessarily mean the gas bill will be any higher. The meter only operates when appliances are turned on. This just means that occasionally during cold weather when all the appliances are on, no fixture would be starving for gas and all can operate at optimum efficiency and capacity. Some Utility Companies only charge a “One-time” fee of only $100 – $150 to upgrade the meter to whatever size you need. Think about it. They want you to buy/use as much gas as you can so they get paid. Nothing wrong with that at all, that is just business. But happy wife is a happy life is not a bad situation either.
Sediment trap
Another important advancement in the gas-fired appliances has been adding a sediment trap to many of the fixtures. This is truly only $10 to $15 of material and a little bit of effort or a handyman call to get done within the hour. The logic goes like this: Many appliances are now containing microchips and little computerized circuits that are able to regulate in very fine detail. The opening in a gas orifice has always been very small just like an old carburetor had different size jet openings for the gas. These tiny holes that are measured in small decimals are only 1/32 or 1/64 of an inch in diameter, etc. Not much bigger than a large sewing needle. And the natural gas that the utility company provides has made it how many miles underground through old steel pipes and can pick up tiny granules of sand, rust and dirt? In the snow belt the gas can even absorb some moisture and send an ice crystal through the pipes.
So to prevent any excessive dirt or contaminant from clogging the tiny orifice of your gas-fired appliance, installing the pipe at the appliance with a little ingenuity to direct the dirt down and away from the appliance opening has now become highly recommended and sometimes mandatory for an appliance manufacturer to prevent voiding their warranty. When put into perspective, wouldn’t you want to protect your $1000 dollar water heater or your $5000 heater by spending $10 to $15?
Gas
It is important to compare the size of the gas meter to the total possible volume of gas-fired appliances on...
For the sake of safety, there is often a steel pole installed referred too as a safety bollard. You will often see this “protecting” a gas meter by the driveway. Basically a pole or set of poles so the teenager or grandma who parks by Braile doesn’t cause an explosion.
