HVAC technicians measure a standard set of items when performing an AC tune-up such as a temperature split, electrical measurements, and refrigerant charge are pretty basic. If you get a technician who has some experience under his belt (or who cares enough) he may measure your static pressure but by doing so he is potentially opening a cans of worms for himself and stepping into the world of home performance (what Green ID is about). I say a can of worms because now he may have to actually crawl past the attic hatch and do some sleuthing of your ductwork, check things he normally doesn’t check for and make recommendations that are not on a standard price sheet. A high static pressure means there are restrictions on your supply ducts (the ones pushing air out and cooling your home) or that there too many restrictions on the return side (the registers where you change the air filter). High static pressures are a major cause for early compressor failures. Lucky for you, there is an easy check to see if you have duct registers that are restrictive or not.
A super easy check every homeowner can do is to simply check what kind of registers you have on the ceilings and walls. Believe it or not the style of register you have has a huge impact on how effectively your heating and cooling runs.
Restrictive supply registers will cause your air to back flow through the ductwork creating imbalances and overworking the AC unit. A restrictive return grille or register will not bring enough return air into the system (or enough out of the other side), starving the unit of air.
How often do we find these restrictive registers during our APS and SRP home energy audits? More often than you think, about 8 out of 10 homes have a restrictive return grille. 4 out of 10 homes have restrictive supply registers.
Stamped faced registers have fixed or semi-fixed grilles that are “stamped” on. The grilles are characterized by smaller openings that are at sharp angles almost parallel to the floor. They not only restrict the airflow out of the the register, but they can’t be adjusted to redirect the air.
High flow registers aka bar type grilles or opposing blade dampeners have fewer grilles, are spaced out less frequently and are sometimes fully adjustable. They let a significantly more amount of air to pass through, making your heating and cooling system work less to keep the home at a comfortable temperature and humidity.
By simply switching your registers you can achieve greater comfort with higher airflow’s into and out of the system.