There are programmable furnace fan timers on the market which address these concerns.
Doorway fans to move heat.
The doorway fan as the name suggests mounts onto the doorframe and pushes the air from one room into the space beyond.
Note that furnace fans can be costly to run continuously and they do create a constant background noise.
This fan s telescoping housing accommodates wall depths of 3 3 4 in.
Designed to fit in any doorway corner it gently circulates air from room to room creating the ideal temperature conditions.
Equipped with 2 speed options this fan allows you to adjust the air transferring power to quickly change or maintain temperatures in adjoining rooms.
Use this room to room circulating fan to move heat around the house ideal for temperature regulation in homes heated with a woodstove pellet stove or fireplace can be mounted in a doorway with hardware included easily reversible single speed 55 cfm 1100 rpm lifelong lubricated motor rated for continuous use single speed.
Amazon s choice for doorway fans to move heat ac infinity axial s1225d dual 120mm muffin fan with speed controller for doorway room to room wood stove fireplace circulation projects 4 4 out of 5 stars 612.
With high level cold air returns the furnace fan can be operated continuously on low speed to move heat around.
This could be further rooms or even into the hall so the warm air can heat the other rooms.
Circulate warm or cool air from 1 room to another using this thru wall room to room fan 7 5 8 in.
This approach can be very effective.
This fan comes in an attractive white finish to match your decor.
The portable specialty fan mounts easily to most door frames with 2 screws included and still allows the door to open and shut.
Ac infinity axial s1238d dual 120mm muffin fan with speed controller ul certified for doorway room to room wood stove fireplace circulation projects.