Morning All!
I got up early and this question popped into my head. I’ve noticed that the majority of the registers for heating and cooling in my home are placed at doorways or at window placements. I noticed that all of the returns upstairs (zoned units) are at the bedroom and bathroom doors, but at mixed locations on the first floor.
First floor has nine (9) registers and three (3) large returns. Upstairs has nine (9) registers and four (4) returns. What is the logic in this? If the idea to cool/heat air at windows and doors that typically deviate from the air in the center of the room? Is the return placement designed for airflow across the room?
Just curious in morning. 🙂
Replies
Short answer-Yes!
The placement of supplies at places of high load (i.e windows and exterior doors) is to mitigate as much as possible that specific load. This is more important in heating than in air conditioning. Returns are ideally placed to create crossflow in the space. High supply, low return. Supply at the extrior, return at the interior.
OTH, the number of supplies, vs returns is simply a matter of compromise/economics. Almost everytime an air flow/comfort problem exists in a residential forced air system, it is due to inadequate and/or inappropriate returns. The common complaint with single zone forced air over two or more floors (its hot upstairs and cold downstairs) is due to inadequate returns. Air should be treated like water: for every supply (except hose bibs) there is a drain; for every supply, there should be a return or exhaust. Returns are not allowed in toilet/ bathrooms and not recommended in kitchens.