A word of caution for those smelling foul orders from their boiler, furnace or hot water heater. It's not uncommon to have multiple animals lodged within pipes or trapped inside appliances. Though in many cases the animals are dead, opening up a pipe or furnace cabinet can release a partially burnt animal and/or other living animals into the dwelling. The same concerns apply for bees/wasps which often nest inside pipes and appliances. We discuss this in more detail at: pvcventscreens.com/putrid-furnace-odor/ Our vent screens are designed to work with existing intake and exhaust vents without modifications to the terminations. While seasonal airflow is extremely important, altering terminations can have unintended consequences such as reducing the flow velocity. Using tees and/or enlarging vents can reduce the exhaust discharge flow and limit how quickly this exhaust is discharged beyond the termination. In many cases, perceived improvements in airflow are negated by a major reduction in flow velocity. It's more important to use our vent screens seasonally as noted on our website. PVS-I and CVC-I series vent screens guard against insects and rodents during the warmer months. 90% airflow rated PVS-R and CVC-R series vent screens are designed for use during sub-freezing temperatures (winter). Using both types of vent screens, seasonally as noted on our website, will guard vents in all seasons from all active threats.

If you reside in a region that experiences sub-freezing temperatures, the insect screen should be removed and replaced with the appropriate 90% airflow rated PVS-R series vent screen for winter use. All-season kits that include both types of screens are available in our store. More information regarding the importance of maintaining a very high rate of airflow during winter is available on our website.

@@pvcventscreens Thanks for the reply! Much appreciated.

In the winter- condensation or melting snow can cause blockage on fine screens which doesnt happen on the more open winter screen's larger openings, I easily understood why they have two season types

Animals often shove these types of screens (discs) right into the vent pipe; sometimes so deep they end up in the furnace along with the animal. Regardless, whether or not a furnace operates with a poor airflow rated screen is a low bar. The degradation in performance from many poor flowing screens will result in an unnecessary load (wear and tear) on the draft inducer motor and reduced energy efficiency in sub-freezing temperatures. That's why we use 90% airflow rated screens during winter.

Yes. PVS-RS and CVC-R series rodent vent screens follow industry standards to prevent mice from gaining entry into vents. See our best practices page at pvcventscreens.com/best-practices/ to view the Fairfax County Health Department's "Controlling Rats & Mice" brochure. As the brochure notes, "mice can squeeze through spaces as small as a nickel!" A much smaller dime won't fit through our rodent screens. Also discussed on our best practices page is the importance of maintaining a high rate of airflow. Since combustion is involved, the screen's impact on airflow is extremely important during winter. When insects are active (spring, summer and fall), PVS-IS and CVC-I series vent screens are designed to guard vents from rodents along with insects (bees, wasps, etc.).

We do sell direct to supply houses, OEMs, HVAC and plumbing companies. However, there are many supply houses we don't sell to and normally when their customers ask for our products that gets the ball rolling. If your local supply house does not carry our products, ask them to look into stocking them. If they are not receptive to your stock request, let us know and we will put you in touch with a national distributor that does carry our products.

@@pvcventscreens Thank you, ITry to be kind to nature