BPP Overview
Flair has built-in protections to safeguard your expensive HVAC equipment.
All Flair homes with Smart Vents are subject to our 1/3 rule, which works to prevent excess static pressure in the supply side of your ducted system. For Flair homes with a Flair Static Pressure Kit installed, we dynamically adjust the % of vents that can close as a result of real-time static pressure readings from the SPK.
Any time the maximum number of Smart Vents is already closed, and Flair determines that an additional Smart Vent needs to close, we consider the Back Pressure Protection (BPP) algorithm in place in your home and determine which Smart Vent to open to allow this next Smart Vent to close. We must open a Smart Vent at this point to avoid excess static pressure in your ducted system. Excess static pressure can negatively impact the efficiency and the longevity of the equipment.
The number of vents that can close is determined initially by the user-specified vent count in the thermostat's zone. If the user specifies that there are 14 supply vents in a thermostat zone, Flair will divide that total by three and then round to the nearest whole number to determine the max number of Smart Vents that are allowed to close.
14 / 5 = 4.67, which rounds to 5, so a maximum of 5 Smart Vents can close in a zone with 14 total supply vents.
13 / 5 = 4.33, which rounds to 4, so a maximum of 4 Smart Vents can close in a zone with 13 total supply vents.
If the maximum number of Smart Vents are closed, and additional vents need to close, Flair will use the Back Pressure Priority algorithm in effect for the Flair home to determine which Smart Vents to open, thus allowing the newly identified Smart Vents to close.
Our 2 Back Pressure Priority Options
Please read the below to understand our two Back Pressure Priority options and how you can change this for your Flair home.
Inactive Rooms
Flair will prioritize keeping Vents closed in Active rooms and will try to open Vents in Inactive rooms first for BPP.
This is typically preferred by customers looking for maximum comfort.
The rooms that are the most uncomfortable get priority. For instance, when cooling, Flair will close Vents in the coldest rooms first.
For example, when cooling, in which of these two rooms will Flair close Smart Vents:
- Room 1 is set to 68F, and is currently 66F --> this room is 2F too cold
- Room 2 is set to 72F, and is currently 68F --> this room is 4F too cold
Room 2 gets priority because it is colder, and the Vents in this room will close first. If Flair has closed the maximum number of vents possible, then the Vents in Room 1 must stay open for BPP.
Active Rooms
Flair will prioritize keeping Vents closed in Inactive rooms and will open Smart Vents in Active rooms first for BPP.
This is typically preferred by customers looking for maximum energy efficiency.
As above, Flair will close the most uncomfortable Inactive rooms first.
Where to change this setting
You can change this setting any time you want in the Flair App.
- Tap on the Main Menu button at the top left of the Flair app.
- Tap Home Settings
- Tap System Settings
- Tap Advanced Features (toward the bottom of the menu)
- Tap Smart Air Routing
- Select the BPP / Smart Air Routing option you prefer