Leaving high efficiency boiler, furnace and hot water heater vent pipes unprotected is not wise. We are constantly reminded of the problems that can occur with horizontal venting systems when our customers contact us with questions regarding our vent protection products. Our customers often describe situations where bees, wasps and animals have made their way into our customers high efficiency boilers, furnaces or hot water heaters and even into their homes. Many of these customers have endured expensive repair bills as well, including service calls from pest control specialists, HVAC technicians and/or plumbers. In fact, some of our customers found out the hard way that OEM wide mesh rodent screens do not stop bugs from entering their appliance’s outdoor vents and causing damage. Because some consumers are facing costly repair bills, and are looking for the right vent protection product for their appliance, we will discuss some of the most common types of products available to homeowners.

PVC Pipe Screens

Allowing any horizontal vented appliance to breathe is important. Even if an appliance is not in use, there is the potential for condensation to accumulate within the pipes. Keeping bugs and animals out of the pipes, while eliminating condensation, can be accomplished with the use of a screen that inserts into the intake and exhaust vent termination hubs. Our specially designed stainless steel vent screen for insects and vent screen for animals is the ideal solution to a major problem many people have; dealing with outdoor hazards that do vary by season. We also offer a complete PVC vent screen kit for those who also want to protect their appliances during spring, summer, winter and fall.

Though plastic PVC pipe screens exist, they are more susceptible to UV damage, can become brittle during repeated heat and thaw cycles and are generally limited to preventing animals from gaining entry into intake and/or exhaust pipes. Additionally, plastic screens can be easily chewed through by a determined animal. Though plastic screens may restrict birds from entering the ventilation system, their effectiveness against chipmunks, moles, mice and squirrels is limited. Nearly all plastic pipe screen products offer no protection from nesting insects such as bees and wasps.

Real stainless steel vent screens, which can be purchased in our store, are the safest and most compatible vent protection solution available. Our screens are designed to maximize airflow, are compatible with the widest range of high efficiency appliances and meet or exceed most manufacturer requirements.

PVC Guards

There are a variety of guards available for vents constructed with PVC. However, most of these guards are not designed for horizontal venting applications and are more commonly found in vertical PVC venting applications such as sanitary/sewage soil stacks. Though these guards may adhere to PVC specifications and fit over common 2”, 3” and 4” pipes, their use in a horizontal venting system can restrict airflow and cause high efficiency appliances to be incapable of fully discharge exhaust gases and create a condition where unhealthy carbon monoxide buildup occurs in the home or business. In other cases PVC vent guards are so restrictive that safety mechanisms within the appliance force a system lockout until the restriction is remedied.

PVC Caps

One of the most cost effective ways to completely close a PVC pipe is with a cap. Though caps may be used on appliances that are shut down for an extended period of time, the risk of condensation is real. This condensation can accumulate, cause mildew and/or mold to grow or even drain back into the appliance. Neither of these conditions is desirable for HVAC and plumbing ventilation systems. Because of the aforementioned reasons, we feel caps should never be used on any high efficiency appliance’s vents. Since caps restrict 100% of the airflow, they definitely can’t be used on running high efficiency appliances.

Despite the problems noted with PVC caps, many people use the word “cap” to universally describe anything that may cover and protect PVC vents. Because of this, we described the three primary types of protective devices used on horizontal vents as PVC pipe screens, guards and caps. Though these are the most common commercially available products available for high efficiency boilers, furnaces and power vent hot water heaters, we have seen a variety of homemade solutions that not only look horrible and risk damaging an appliance, but they also can pose a danger to the health of the occupants of a home.

Covering the outside of an intake or exhaust vent pipe should be avoided. External objects placed over the top of vents, such as zip-tied mesh screen, socks and other objects are unsafe. Especially during winter, snow melt can cause ice to accumulate over anything that is bound to the outside of a pipe. It is far safer to use a screen that fits into the inside of an elbow/hub. With the screen being positioned inside of the elbow/hub it is shielded from rain, snow and lawn debris that could collect and restrict airflow.

Though this page describes the primary differences between PVC pipe screens, guards and caps, we encourage you to visit our FAQ page to learn more about the questions we receive about our PVC vent screen products. By reviewing the common questions we answer, you will be better prepared to make an informed purchasing decision when buying a product to protect your high efficiency appliance.