Missing Second Floor HVAC Return….
Recently I inspected a brand new home and as I looked at the HVAC system I was amazed to find that the Builder had installed the interior air handler in a first floor utility closet. For returns he installed open return grates in the side wall of the closet in the living room and adjoining first floor bedroom. The unit was open on top in the closet. Problem is he failed to provide for returns on the second floor. He provided supply vents in each of the second floor rooms but no way for the air to recirculate. In this situation there is no way to effectively condition the air on the second floor, in the summer it will always be hot and in the winter it will always be cold. The rule is always have at least one return on each floor so that the air can be drawn into the system heated or cooled and distruted back into that area.
Watch Your Savings Grow
Using native trees and plants in your yard creates a beutiful, low-maintenance and water-saving garden which attracts birds, butterflies and animals. Wisely landscaped yards may lower greenhouse gas emissions, as well as home energy costs.
Don’t Trash Those Scraps
Backyard composting is an all-around win-win. It’s a great way to reduce waste and help your garden at the same time. You can include most food scraps and materials, such as cardboard, which will decompose in your yard and produce nutrient-rich fertilizer.
Ten Important Questions to Ask Your Home Inspector
1. What does your inspection cover? The inspector should ensure that their inspection and inspection report will meet all applicable requirements in your state if applicable and will comply with a well-recognized standard of practice and code of ethics. You should be able to request and see a copy of these items ahead of time and ask any questions you may have. If there are any areas you want to make sure are inspected, be sure to identify them upfront.
2. How long have you been practicing in the home inspection profession and how many inspections have you completed? The inspector should be able to provide his or her history in the profession and perhaps even a few names as referrals. Newer inspectors can be very qualified, and many work with a partner or have access to more experienced inspectors to assist them in the inspection.
3. Are you specifically experienced in residential inspection? Related experience in construction or engineering is helpful, but is no substitute for training and experience in the unique discipline of home inspection. If the inspection is for a commercial property, then this should be asked about as well.
4. Do you offer to do repairs or improvements based on the inspection? Some inspector associations and state regulations allow the inspector to perform repair work on problems uncovered in the inspection. Other associations and regulations strictly forbid this as a conflict of interest.
5. How long will the inspection take? The average on-site inspection time for a single inspector is two to three hours for a typical single-family house; anything significantly less may not be enough time to perform a thorough inspection. Additional inspectors may be brought in for very large properties and buildings.
6. How much will it cost? Costs vary dramatically, depending on the region, size and age of the house, scope of services and other factors. A typical range might be $200-$500, but consider the value of the home inspection in terms of the investment being made. Cost does not necessarily reflect quality. HUD Does not regulate home inspection fees.
7. What type of inspection report do you provide and how long will it take to receive the report? Ask to see samples and determine whether or not you can understand the inspector’s reporting style and if the time parameters fulfill your needs. Most inspectors provide their full report within 24-48 hours of the inspection.
8. Will I be able to attend the inspection? This is a valuable educational opportunity, and an inspector’s refusal to allow this should raise a red flag. Never pass up this opportunity to see your prospective home through the eyes of an expert.
9. Do you maintain membership in a professional home inspector association? There are many state and national associations for home inspectors. Request to see their membership ID, and perform whatever due diligence you deem appropriate.
10. Do you participate in continuing education programs to keep your expertise up to date? One can never know it all, and the inspector’s commitment to continuing education is a good measure of his or her professionalism and service to the consumer. This is especially important in cases where the home is much older or includes unique elements requiring additional or updated training.
Backdrafting
Backdrafting
By Nick Gromicko, Rob London and Kenton Shepard
Backdrafting is the reverse flow of gas in the flues of fuel-fired appliances that results in the intrusion of combustion byproducts into the living space. Many fuel-fired water heaters and boilers use household air and lack an induced draft, which makes them especially vulnerable to backdrafting when indoor air pressure becomes unusually low. Inspectors should try to spot evidence of backdrafting in homes.
How does backdrafting happen?
Fuel-fired water heaters, boilers, wall heaters, and furnaces are designed to exhaust the byproducts of combustion to the outdoors through a flue. These hot gases rise through the flue and exit the home because they are not as dense as indoor air. The pressure differential that allows for the release of combustion gases can be overcome by unusually low indoor air pressure caused by a high rate of expulsion of air into the outdoors through exhaust fans, fireplaces and dryers. When this happens, combustion gases can be sucked back into the house and may potentially harm or kill building occupants. Improperly configured flues or flue blockages can also cause backdrafting.
How can inspectors test for backdrafting?
- An inspector can release smoke or powder into the draft diverter to see whether it gets sucked into the duct or if it spills back into the room. A smoke pencil or a chemical puffer can be used to safely simulate smoke.
- An inspector can hold a lighter beside the draft diverter to see whether there is sufficient draft to pull the flame in the direction of the flue.
- Combustion gases that back-draft into a house may leave a dark residue on the top of the water heater. The presence of soot is an indication of backdrafting, although its absence does not guarantee that backdrafting has not happened.
- A carbon monoxide analyzer can be used to test for backdrafting of that gas. Inspectors should be properly trained to use these before they attempt to use one during an actual inspection. False-negatives from these devices that are documented in inspection reports can lead to liability issues.
While performing the above-noted tests, it is helpful if inspectors ask their clients to turn on all devices that vent air into the outdoors in order to simulate worst-case conditions. Such devices may be dryers, or bathroom and kitchen fans.
Types of fuel-fired water heaters:
· Atmospheric Draft
Most backdrafting is the result of the characteristics of this type of water heater. Combustion gases rise through the ventilation duct solely by the force of convection, which might not be strong enough to counter the pull from dips in indoor air pressure.
· Induced Draft
This system incorporates a fan that creates a controlled draft. The potential for backdrafting is reduced because the induced draft is usually strong enough to overcome any competing pull from an indoor air-pressure drop.
· Sealed Combustion
The combustion and venting systems are completely sealed off from household air. Combustion air is drawn in from the outdoors through a pipe that is designed for that purpose. The potential for backdrafting is nearly eliminated because the rate of ventilation is not influenced by indoor air pressure, and the vented gas has no pathway into the home.
· Water Heater Location
The installation of fuel-fired water heaters in particular household locations can increase the chances of personal harm caused by backdrafting. The 2006 edition of the International Residential Code (IRC) states the following concerning improper location:
Fuel-fired water heaters shall not be installed in a room used as a storage closet. Water heaters located in a bedroom or bathroom shall be installed in a sealed enclosure so that combustion air will not be taken from the living space.
Condensation in Double-Paned Windows
Condensation in Double-Paned Windows
by Nick Gromicko, Rob London and Kenton Shepard
Condensation is the accumulation of liquid water on relatively cold surfaces.
Almost all air contains water vapor, the gas phase of water composed of tiny water droplets. The molecules in warm air are far apart from one another and allow the containment of a relatively large quantity of water vapor. As air cools, its molecules get closer together and squeeze the tiny vapor droplets closer together as well. A critical temperature, known as dew point, exists where these water droplets will be forced so close together that they merge into visible liquid in a process called condensation.
Household air is humidified from high levels of water vapor in human and animal exhalation, plant transpiration, and fixtures such as showers and dryers. This humidity can rise significantly higher than outside air because of the insulative design of a house. Cold indoor surfaces can cool the surrounding air enough to force vapor to condense. This often happens on single-pane windows because they lack the necessary thermal insulation available to better windows. Double-pane windows have a layer of gas (usually argon or air) trapped between two panes of glass and should be insulated enough to prevent the accumulation of condensation. If this type of window appears misty or foggy, it means that its seal has failed and the window needs to be replaced.
Silica Desiccant
A desiccant is an absorptive material designed to maintain dryness within its vicinity. A common type of desiccant is silica gel, a porous plastic used to prevent spoilage in various food products. A tightly packed assortment of silica pellets is contained inside the aluminum perimeter strip of a window to dehumidify incoming household air that was not stopped by the window’s seal. If not for this substance, incoming air could condense on the glass.
Silica gel has an immense surface area, approximately 800 m²/g, which allows it to absorb water vapor for years. Eventually, the silica pellets will become saturated and will no longer be able to prevent condensation from forming. A double-paned window that appears foggy has failed and needs to be repaired or replaced.
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.
Window condensation will inevitably lead to irreversible physical window damage. This damage can appear in the following two ways:
Riverbedding – Condensed vapor between the glass panes will form droplets that run down the length of the window. Water that descends in this fashion has the tendency to follow narrow paths and carve grooves into the glass surface. These grooves are formed in a process similar to canyon formation.
Silica Haze – Once the silica gel has been saturated, it will be eroded by passing air currents and accumulate as white “snowflakes” on the window surface. It is believed that if this damage is present, the window must be replaced.
Thermal Imaging as a Detection Tool
The presence of condensation in double-paned windows means that they have failed, but the absence of condensation does not mean the window is functional. This latter fact is especially true in hot, dry environments, and when the temperature inside of a house is the same as the temperature outside. A method has recently developed that uses infrared (IR, thermal) imaging to provide a better determinant of faulty windows.
Home inspectors can become trained to use thermal imaging cameras to test for heat transfer through windowpanes (and other interior locations). In InterNACHI’s thermal imaging course, John McKenna explains how an IR camera can be used to identify failed windows by imaging unusual temperature gradients. Even the slightest entry of cold, outside air into the home that would ordinarily go unnoticed will stand out as a dark blue haze in an IR image. A trained inspector can either stand outside or inside the house and watch for the escape of warm air or the entrance of cool air, respectively. A trained inspector will compare images of individual windows in a residence and look for anomalies.
In summary, condensation in double-paned windows indicates that the window has failed and needs to be replaced. Condensation, while it can damage windows, is itself a symptom of a lack of integrity of the window’s seal. A failing seal will allow air to transfer in and out of the window even if it is firmly closed. Inspectors should be aware of this process and know when to recommend that clients’ windows be replaced.
Helpful Hints from Your Neighborhood Home Inspector
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