[Tom27]

I have a 3400 sqft 2 story single family home and having trouble maintaining the room temperatures on the second floor. I have a central HVAC system with two zones. One for the first level and the other for the second floor. The first floor has no problem maintaining a consistent temperature since it is open concept. The second floor has all of the bedrooms and we keep the doors closed.

Each room sees different heat loads due to how many windows and ones see the most sun light. One of the bedrooms has the most windows and sees the most sunlight. During the summer, its the warmest bedroom so I adjust dampers to restrict air from other bedrooms so that it will receive more air and keep all the rooms at a similar temperature. During the winter, the same room is still the warmest room due to being the sunniest room but now it receives way too much heat and I have to restrict air flow to that room so I can direct more air to the cold rooms.

My house is three years old and the HVAC system easily handles the heating and cooling needs. My issue is finding the right air flow balance. I am considering adding another zone to give the master suite its own zone. That would allow me to maintain the temperature there easily but it doesn't fix the temperature difference in the other three bedrooms which are the warmest and coldest rooms in the house.

Would programming the fan to run every hour or so help maintain an even temperature across the bedrooms?

 

[beenthere]

It will help some.

 

[Flyers28]

Where are your returns located? You can dump all of the air you want into a space but if don't have sufficient returns it won't do any good. Trying leaving the doors open. I'll bet it fixes your problem!

 

[Tom27]

I have one large return at the top of the stairs for the second floor and another one on the first floor. We really would like to avoid leaving the doors open. That really negates the idea of having doors in your house. I'll give it a try to test it out. If that makes the improvement, then I need to consider how to improve air flow from the bedrooms with the doors closed. Perhaps add some wall vents to allow more air flow. As it is now, you can feel a strong breeze from the air being drawn underneath of the doors. The upstairs return is at the top of the stairs and is in the center of the hall way. Would it be better to add more returns, perhaps one at each end of the hall rather than one large one at the top of the stairs?

 

[Flyers28]

Your best thing to do would be to add returns in esch room. I understand that it isn't always possible. If you can feel a string breeze under the doors it is starving for air. You could install transfer grills above the doors if you have room. Basically you cut a hole in the drywall in the wall in the room and one in the wall in the hallway and put a grill on both sides. The air can then be pulled from the room into the hallway and then into the main return.

 

[Tom27]

Thanks for the suggestions. I'll definititly see how things improve by keeping the doors open. Then I'll have to weigh my options from there. I have plenty of room to work with so it sounds like I have several options to consider.

One more thing. The supply is in the ceiling. If I added returns in each room, would it be best to add it the furthest away from the supply and close to the floor rather than adding the returns in the ceiling?

Thanks,

 

[Flyers28]

Away from the supply but keep them in the ceiling. Returns are most important for a/c since hot sir rises. You could be adventurous and out them high and low. Close off the high one in winter and low one in summer.

 

[digitalplumber]

Your best thing to do would be to add returns in esch room. I understand that it isn't always possible. If you can feel a string breeze under the doors it is starving for air. You could install transfer grills above the doors if you have room. Basically you cut a hole in the drywall in the wall in the room and one in the wall in the hallway and put a grill on both sides. The air can then be pulled from the room into the hallway and then into the main return.

Could not agree with this more as a homeowner, it was not until we installed returns in each room upstairs, that things got better.

 

[handyman_20772]

Keeping your doors open will help, and adding individual returns in each room will help even more. If they are installed in your attic ensure the ducts are insulated and sealed properly.