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Inspecting Generators & Hazards

4/2/2018

Homeowners may use a generator to supply electricity to their home in the case of a power outage, either out of necessity or convenience. Inspectors may want to know about generators and the potential hazards they present when improperly wired or utilized.

Generator Types
There are two main types of generators: permanently installed, standby generators; and gasoline-powered, portable generators.

Standby Generators

Standby generators typically operate on natural gas or liquid propane. They remain fixed in place outside the home and are designed to supply on-site power to specified circuits through a home's electrical wiring. These generators work in tandem with a manual or automatic transfer switch, which automatically detects an interruption in grid-powered electricity and subsequently transfers over electrical input to the generator.

The transfer switch suspends input from the generator once it senses that utility-powered electricity has resumed. Generators for small- to medium-size homes are typically air-cooled and employ fans to regulate the temperature inside the unit. Liquid-cooled units are used for the larger energy loads in larger homes.

Some advantages of standby generators are as follows:

They may be turned on manually, or they may be programmed to switch on automatically in the case of a power outage even when no one is home.
Power may be supplied for extended periods of time.
Hard-wired systems, such as a home's furnace, well pump and air conditioner, may maintain continuous power.
Uninterrupted power can be supplied to systems that must remain on continuously, such as medical equipment used for breathing, etc.

Disadvantages of standby generators are as follows:

Installation may require a permit.
A qualified technician, such as an electrician, is required to install the ATS and to determine the electrical load requirements for the circuits in a home.
Routine maintenance is required.
Standby generators may be prohibitively expensive.

Portable Generators

Gasoline-powered, portable generators are typically smaller in size and power capacity than permanently installed generators. They are designed so that corded electrical devices may be plugged directly into them.

Gasoline-powered, portable generators are typically smaller in size and power capacity than permanently installed generators. They are designed so that corded electrical devices may be plugged directly into them.

Advantages to portable generators are as follows:

Portable generators are versatile. They may be used at home or transported and utilized in remote locations, such as a campground or a construction site.
They do not require complicated installation.
They typically do not require permits.
Portable units are generally less expensive than standby generators.

Disadvantages of portable generators:

Devices that are hard-wired into a home's electrical system cannot be powered by a portable generator if no transfer switch is installed.

Hazards

Portable and standby generators produce dangerous carbon monoxide (CO) gas, which can be deadly if inhaled.
Inexperienced installers are exposed to the risk of electrical shock. Only qualified electricians should attempt to install a generator.
Overloading a generator may result in reduced fuel efficiency, damage to appliances or fire.
Standby generators or their required transfer switches that are incorrectly wired (or missing) may result in "back-feed" -- a hazardous condition in which an electrical current is fed back into the grid -- which could potentially electrocute and kill homeowners, utility workers, and others who are using the same utility transformer.
Connecting a portable generator directly into a home's wall outlet can also cause dangerous back-feed.
Generators that are exposed to water or that are not properly grounded can cause electrocution.
Gasoline for portable generators is highly flammable and may cause a fire when exposed to an open flame or when spilled on the hot generator.
Over-taxed cords attached to a portable generator may cause a fire.

Inspecting A Generator

InsideOut inspectors check for the following:

Generators should never be used anywhere indoors, even if the area is ventilated.
Portable generators placed outside should not be near doors, vents or open windows leading into the home.
Carbon-monoxide detectors should be installed in case CO is accidentally released into the home.
A standby generator hard-wired into a home should have a transfer switch installed to prevent backfeeding. An inspector can locate this device situated between
Generators should be properly grounded.
Units should be dry and shielded from contact with liquid.
Only heavy-duty electrical cords that are rated for outdoor use should be plugged into portable generators.
Electrical cords should not have any punctures or exposed wiring.
Cords running from portable generators should be kept out of the way of foot traffic and should not run underneath rugs.
The total electrical capacity of the generator should exceed the power requirements of the devices that the unit is supplying.
Fuel for portable generators should be stored away from the home and children in clearly labeled and durable containers.

In summary, generators can be lifesavers during a power outage, but they present serious health and safety concerns if they are not installed and used properly.

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Central Humidifiers: What, How & Why!

2/12/2018

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Humidifiers are devices that humidify air so that building occupants are comfortable. Central humidifiers are hard-wired into a house’s plumbing and forced-air heating systems.

What is humidity?
Humidity refers to the amount of moisture in the air. “Relative humidity” signifies the amount of moisture in the air relative to the maximum amount of water the air can contain before it becomes saturated. This maximum moisture count is related to air temperature in that the hotter the air is, the more moisture it can hold. For instance, if indoor air temperature drops, relative humidity will increase.

How do central air humidifiers work?
Central air humidifiers are integrated into the forced-air heating system so that they humidify air while it is being heated. The water that is used by the device is pumped automatically into the humidifier from household plumbing, unlike portable humidifiers, which require the user to periodically supply water to the device. Humidifiers are available in various designs, each of which turns liquid water into water vapor, which is then vented into the house at an adjustable rate.

Why humidify air?
Certain airborne pathogens, such as those that cause the flu, circulate easier in dry air than in moist air. Moist air also seems to soothe irritated, inflamed airways. For someone with a cold and thick nasal secretions, a humidifier can help thin out the secretions and make breathing easier.

Indoor air that is too dry can also cause the following problems:

damage to musical instruments, such as pianos, guitars and violins;
dry skin;
peeling wallpaper;
static electricity, which can damage sensitive electrical equipment, cause hair to stick up, and can be painful or annoying; and
cracks in wood furniture, floors, cabinets and paint.

Central Humidifier Dangers
Humidifiers can cause various diseases. The young, elderly and infirm may be particularly at risk to contamination from airborne pollutants, such as bacteria and fungi. These can grow in humidifiers and get into the air by way of the vapor where it can be breathed in. Some of the more common diseases and pathogens transmitted by humidifiers are:

Legionnaires’ Disease. Health problems caused by this disease range from flu-like symptoms to serious infections. This problem is generally more prevalent with portable humidifiers because they draw standing water from a tank in which bacteria and fungi can grow;
thermophilic actinomycetes. These bacteria thrive at temperatures of 113° to 140° F and can cause hypersensitivity pneumonitis, which is an inflammation of the lungs; and
“humidifier fever,” which is a mysterious and short-lived, flu-like illness marked by fever, headache, chills and malaise, but without prominent pulmonary symptoms. It normally subsides within 24 hours without residual effects.

Other problems associated with humidifiers include:

accumulation of white dust from minerals in the water. These minerals may be released in the mist from the humidifier and settle as fine white dust that may be small enough to enter the lungs. The health effects of this dust depend on the types and amounts of dissolved minerals. It is unclear whether these minerals cause any serious health problems;
moisture damage due to condensation. Condensed water from over-humidified air will appear on the interior surfaces of windows and other relatively cool surfaces. Excessive moisture on windows can damage windowpanes and walls, but a more serious issue is caused when moisture collects on the inner surfaces of exterior walls. Moisture there can ruin insulation and rot the wall, and cause peeling, cracking or blistering of the paint; and
accumulation of mold. This organic substance grows readily in moist environments, such as a home moistened by an over-worked humidifier. Mold can be hazardous to people with compromised immune systems.

Designs and Maintenance

drum-type humidifier: has a rotating spongy surface that absorbs water from a tray. Air from the central heating system blows through the sponge, vaporizing the absorbed water. The drum type requires care and maintenance because mold and impurities can collect in the water tray. According to some manufacturers' instructions, this tray should be rinsed annually, although it usually helps to clean it several times per heating season.

flow-through or “trickle” humidifier: a higher quality though more expensive unit than the drum-type, which allows fresh water to trickle into an aluminum panel. Air blows through the panel and forces the water to evaporate into the air stream. Excess water exits the panel into a drain tube. This design requires little maintenance because the draining water has a “self-cleaning” effect and, unlike the drum-type humidifier, there is no stagnant water.

Other tips that InterNACHI inspectors can pass on to their clients:

If equipped with a damper, it should be closed in the summer and opened in the winter. The damper may appear as a knob that can be set to “summer” or “winter” setting, or it may be a piece of metal that can be inserted to cover the duct opening.
The humidifier is controlled by a humidistat, which must be adjusted daily. Some new models do this automatically, although most require daily attention from building occupants. The humidistat should contain a chart that can be used to identify the proper setting based on the outdoor temperature. If this adjustment is not performed, condensation will likely collect on cool surfaces and potentially lead to mold or wood rot. Many homeowners do not know that this calibration is necessary.
The furnace might need to be checked for rust. Some humidifiers are installed inside the plenum of the furnace, which can be damaged by rust if the humidifier leaks.
Central humidifiers may have a solid core that should be replaced each year. The manufacturer’s instructions should be consulted regarding this replacement.

In summary, central humidifiers are used to humidify air to make it more comfortable, but they can cause health problems and building damage if they are not properly maintained.

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Anti-Scald Valve: What They Do To Protect You!

1/18/2018

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Anti-scald valves, also known as tempering valves and mixing valves, mix cold water in with outgoing hot water so that the hot water that leaves a fixture is not hot enough to scald a person.

Facts and Figures

Scalds account for 20% of all burns.
More than 2,000 American children are scalded each year, mostly in the bathroom and kitchen.
Scalding and other types of burns require costly and expensive hospital stays, often involving skin grafts and plastic surgery.
Scalding may lead to additional injuries, such as falls and heart attacks, especially among the elderly.
Water that is 160º F can cause scalding in 0.5 seconds.

Unwanted temperature fluctuations are an annoyance and a safety hazard. When a toilet is flushed, for instance, cold water flows into the toilet’s tank and lowers the pressure in the cold-water pipes. If someone is taking a shower, they will suddenly feel the water become hotter as less cold water is available to the shower valve. By the same principle, the shower water will become colder when someone in the house uses the hot-water faucet. This condition is exacerbated by plumbing that’s clogged, narrow, or installed in showers equipped with low-flow or multiple showerheads. A sudden burst of hot water can cause serious burns, particularly in young children, who have thinner skin than adults. Also, a startling thermal shock – hot or cold – may cause a person to fall in the shower as he or she scrambles on the slippery surface to adjust the water temperature. The elderly and physically challenged are at particular risk.

Anti-scald valves mitigate this danger by maintaining water temperature at a safe level, even as pressures fluctuate in water supply lines. They look similar to ordinary shower and tub valves and are equipped with a special diaphragm or piston mechanism that immediately balances the pressure of the hot- and cold-water inputs, limiting one or the other to keep the temperature within a range of several degrees. As a side effect, the use of an anti-scald valve increases the amount of available hot water, as it is drawn more slowly from the water heater. Inspectors and homeowners may want to check with the authority having jurisdiction (AHJ) to see if these safety measures are required in new construction in their area.

Installation of anti-scald valves is typically simple and inexpensive. Most models are installed in the hot-water line and require a cold-water feed. They also require a swing check valve on the cold-water feed line to prevent hot water from entering the cold-water system. They may be installed at the water heater to safeguard the plumbing for the whole building, or only at specific fixtures.

The actual temperature of the water that comes out of the fixture may be somewhat different than the target temperature set on the anti-scald valve. Such irregularities may be due to long, uninsulated plumbing lines or defects in the valve itself. Users may fine-tune the valve with a rotating mechanism that will allow the water to become hotter or colder, depending on which way it’s turned. Homeowners may contact an InterNACHI inspector or a qualified plumber if they have further questions or concerns.

In summary, anti-scald valves are used to reduce water temperature fluctuations that may otherwise inconvenience or harm unsuspecting building occupants.

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Inspecting Generators & Hazards

Central Humidifiers: What, How & Why!

Anti-Scald Valve: What They Do To Protect You!

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