Kimmell Inspection Services

Sediment traps at water heaters and furnaces

admin — Tue, 22 Nov 2011 19:16:16 +0000

A question I get asked about frequently is what is a sediment trap, and what is its purpose. I have installed a number of water heaters over the years and have found that within the last 4-5 years, all water heater manufactures recommend installing a sediment trap. If you do not install a sediment trap on your new water heater, it will void the warranty. The installation of this trap at the water heater as well as the furnace is also a requirement of the Claifornia Plumbing Code; 1212.7

The installation of a trap is a safety feature, and can extend the life of your water heater or furnace. What a sediment trap does is keeps moisture and small particles that may be in the natural gas or propane from clogging the small orifices that are within the gas valve assembly at the appliances, and the burners as well. The gas valve assembly for a water heater is where the temperature selection knob is located. If any of these orifices get clogged, the pilot for a water heater, and or the burners for both the water heater or furnace will not operate correctly which could lead to a hazardous condition.

A sediment trap should be as close to the water heater or furnace as possible, but down stream of the shut off valve for these gas fired appliances. This is so the gas can be shut off and the trap checked if necessary. The trap is installed where the gas flow must make a 90 degree turn just before the gas valve assembley. In order to prevent clogging, moisture or particals in the natural gas, or propane gas will settle in the trap. This trap is simply a short length of pipe (or nipple) facing downward that is a minimum of 3 inches long, is threaded at the bottom that is capped.This is a very inexpensive component, and only takes a few minutes to install, but provides safety, and prolongs the life of the appliance.

Testing air conditioners during cold weather can damage the system

admin — Tue, 08 Nov 2011 01:19:09 +0000

It is often asked why home inspectors do not test air conditioning systems during the cold months. Without getting into the specific science of how an air conditioning system works, it is primarily a science of the compression of gas into a liquid, and expansion of this liquid back into a gas. These two functions occur at the condensor coil, which is large piece of equipment located at the exterior of the building, and the evaporator coil that is located at the furnace. When the outside temperature is too cold, (or sometimes even cold indoor temperatures), it is possible the gases in the air conditioning system's "suction" portion of the refrigerant line can turn to a liquid. Turning on the air conditioner when the gas is a liquid can cause the liquid to "slug the compressor" which can cause damage to valves within the compressor. The compressor is a component of the exterior condensor coil, which is the large unit on the outside of a building that also houses a large fan. Depending on the specific manufacturer, the lowest temperature where it is advised not to operate the system varies between 50 degrees and 65 degrees, in a time frame that also varies anywhere from 12 to 48 hours prior to turning on the system, it all depends on different brands. As general home inspectors, we use the lowest common denominators. It is possible that Heating and Ventilation contractors (HVAC) also may not be able to test this equipment if the weather is too cold. Some types of air conditioners have components built into the system that prevent the gas from turning into a liquid during the cold weather, however, as home inspectors we are not qualified to, or for that matter able to visually identify this particular type of feature. When purchasing a home warranty, it would be prudent to make sure this warranty includes the air conditioning system.

Are your smole alarms safe

admin — Tue, 30 Aug 2011 19:16:42 +0000

The most common smoke alarms in residences are an ionization-type. These are the type of smoke alarms that most builders and homeowners install, and what is readily available at hardware stores. It is strongly recommended that ALL ionization-type smoke alarms – regardless of age – be replaced with PHOTOELECTRIC technology smoke alarms. Photoelectric smoke alarms have been shown to respond much more reliably under most real-world conditions. Nearly 95% of the smoke alarms installed in residences in the US are IONIZATION technology alarms. There is significant scientific research that shows that ionization alarms WILL FAIL TO RESPOND to the smoldering/heavy most often found in residential fires. Ionization alarms are also notorious for nuisance tripping from cooking, bath shower steam, etc. Ionization alarms are approved for use and do comply with the legal requirements for smoke alarms on transfer in MOST jurisdictions. However, due to the significant failure rate in real-world fire situations, these alarms pose a significant life-safety risk to the occupants. Verifying the type of alarm installed is not part of this inspection and is specifically disclaimed. All smoke alarms should be tested per the manufacturer's instructions and replaced at least every 10 years to insure proper function. Interested parties should consult with a qualified trade specialist for service.

Failed dual paned windows

admin — Mon, 23 Aug 2010 22:56:23 +0000

One of the most common findings a property inspector observes, and one of the most taxing to not only the owner of a property, but to the prospective buyer and both agents involved in the sales transaction is "Failed Windows". Failed hermetic seals ( failed glazing) is most commonly found in early generation dual paned windows, those that were manufactured between the early 80's – up to the late 90's and even in some instances, the early 2000's. Since, most window vendors have refined the process of manufacturing these windows, and failed seals are not as common.

The following article was written by Nick Gromicko, Rob London and Kenton Shepard

Why Double-Paned Windows Fail – Solar (Thermal) Pumping

Although double-paned windows appear to be stable, they actually experience a daily cycle of expansion and contraction caused by “thermal pumping.” Sunlight heats the airspace between the panes and causes the gas there to heat up and pressurize. Expanding gas cannot leave the chamber between the panes and causes the glass to bulge outward during the day and contract at night to accommodate the changing pressures. This motion acts like the bellows of a forge, pumping minute amounts of air in and out of the airspace between the panes. Over time, the constant pressure fluctuations caused by thermal pumping will stress the seal and challenge its ability to prevent the flow of gas in and out of the window chamber. Incoming humid air has the potential to condense on the window surface, if it is cold enough.

Can Failed Windows be Repaired?

Inspectors should be aware that there are companies that claim to be able to repair misty windows through a process known as “defogging.”

This repair method proceeds in the following order:

A hole is drilled into the window, usually from the outside, and a cleaning solution is sprayed into the air chamber.
The solution and any other moisture are sucked out through a vacuum.
A defogger device is permanently inserted into the hole that will allow the release of moisture during thermal pumping.

Inspectors should know that there is currently a debate as to whether this process is a suitable repair for windows that have failed or if it merely removes the symptom of this failure. Condensation appears between double-paned windows when the seal is compromised and removal of this water will not fix the seal itself. A window “repaired” in this manner, although absent of condensation, might not provide any additional insulation. This method is still fairly new and opinions about its effectiveness range widely. Regardless, “defogging” certainly allows for cosmetic improvement, which is of some value to homeowners. It also removes any potential damage caused by condensation in the form of mold or rot. Thanks to the authors of this article.

In my opinion, as in all new products, this method has yet to be time tested, and it is more sensible to replace any failed windows

Duct tape should not be used to seal ducting

admin — Wed, 18 Aug 2010 00:04:39 +0000

When conducting an inspection of the components within a crawl space, which includes a general observation of the ducting for the heating and cooling system of a residence, I sometimes come across sections of ducting that are disconnected at the joints, or very poorly sealed. I don't make an attempt to remove any ducting insulation that is perfectly intact in order to view the joints in the ducts. In instances where the insulation (if present) is loose, damaged, or missing, and the joints are clearly viewable, I will have a look at random samples of these joints. I commonly find that duct tape was used to seal the joints, and the tape has become very frail and sometimes so damaged that there are joint separations which allows heat or cooled air to treat the air within the crawl space. This means less treated air into the rooms of the house which in turn is very inefficient and costly.

As the name implies, one would naturally expect to find Duct tape used to seal the joints in the ducting for heating and ventilation in buildings, however, it is not intened to be used for such purpose, and is not what a property inspector wants to find when examining the ducting. Duct tape is a polyethylene, reinforced, multi-purpose pressure sensitive tape with a soft and flexible shell and pressure sensitive adhesive. It is generally silver or black in color but many other colors have recently become available, and can be purchased at hardware stores, and some drug stores and super markets. It has many uses, and can be found among the tool collection of most home owners.

Duct tape was never intended to be used to seal ducting, Originally developed in 1942, during World War II as a water resistant sealing tape for ammunition cases. Permacel, then a division of Johnson & Johnson, used a rubber-based adhesive to help the tape resist water and a fabric backing to add strength. It was also used to repair military equipment quickly, including jeeps, firearms, and aircraft because of these properties.

To provide lab data about which sealants and tapes last, and which are likely to fail, research was conducted at Lawrence Berkeley National Laboratory Environmental Energy Technologies Division. Their major conclusion was that one should not use duct tape to seal ducts (specialty tapes are available for this purpose). (They defined duct tape as any fabric-based tape with rubber adhesive.) The testing done shows that under challenging but realistic conditions, duct tapes become brittle and may fail. It is very common for me to find duct tape that has become very frail, and in most instances, is allowing a significant amount of heated or air conditioned air to escape the ducting instead of through them to the registers in the room of the building. This means the system is not very efficient, and is costing the property owner money to condition the air in either the attic or the crawl space under the building, (where ever the systems ducting is located). Commonly duct tape carries no safety certifications such as UL or Proposition 65, which means the tape can violently burn, produce toxic smoke, ingestion and contact toxicity, irregular mechanical strength, and low life expectancy for the adhesive on the tape. Its use in ducts has been prohibited by the state of California, and by building codes in most other places in the U.S. However, metalized and aluminum tapes used by professionals are still often called "duck/duct tapes".

Anti-Siphon Valves (Air Gaps)

admin — Tue, 25 Sep 2007 15:39:33 +0000

Home inspectors in California should comment on the lack of an air gap in the kitchen, and in the instance of a newer installation usually results in some controversy. I will try to explain the need for this device as easy as possible. An air gap is a device that is usually chrome in color, (other colors are available), that is mounted on the top of the counter near the kitchen sink and facilitates proper drainage of the dishwasher. The lack of this device creates a potential health hazard due to contaminates that originate in drain pipes, drain trap, or the garbage disposal from siphoning back into the dishwasher, and because the water supply to this appliance enters level to, or below the drain line, it is necessary to prevent cross connection, or back siphoning which could allow drain water to mix with supply water. One can imagine the health risks in any one of these events. Most of the newer high end appliances have a built in anti-siphon device or integral backflow device that is connected to the drain hose from the dishwasher, and is clearly visible inside the cabinet under the kitchen sink, and an additional air gap on top of the sink may not be necessary, Miele being one of those brands. Local building departments have differing views of these built in devices as to whether they are accepted or not, and I recommend inquiry with the governing building department in regards to their specific requirements.

"UPC 807.4 No domestic dishwashing machine shall be directly connected to a drainage system or food waste disposer without the use of an approved dishwasher airgap fitting on the discharge side of the dishwashing machine. Listed airgaps shall be installed with the flood level (FL) marking at or above the flood level of the sink or drainboard, whichever is higher".