bonus room

[mharwell01]

I have an approx. 250 sq ft bonus room over my garage that I enter through the upstairs master bedroom. The room is insulated and Id like to heat/cool it if possible. It would require about 30' of duct for supply and return. If I wanted to run a 4" supply to the room
- is it a simple matter of installing the duct from the main trunk to the room.
- there is an existing 4" duct to a bathroom beside the bonus room. would it be acceptable to run a larger supply to this vent and split off it to the bonus room?
- do i need to run a return all the way back to the main trunk? Or, there is an existing return in the bedroom next to the bonus room, can i connect the bonus return to this?

i dont need this room to be heated/ cooled like the rest of the living area. Id just like it not to be freezing in winter and like a sauna in summer. Its really just used for storage and closet space.

any input is appreciated.

[beenthere]

With a 4", it will still be roasting in the summer, and freezing in the winter.


Contact a local contractor.

Sorry, this is not a DIY site.

[m kilgore]

Bonus rooms can be very hard to heat and cool. If not done with the origonal install then your system most likely was not sized to handls the extra square footage.

You need to have some calculations run to find out if the current system is large enough and how to set up the duct. Call your local hvac pro to help you with this.

[fincomber569]

I have an approx. 250 sq ft bonus room over my garage that I enter through the upstairs master bedroom. The room is insulated and Id like to heat/cool it if possible. It would require about 30' of duct for supply and return. If I wanted to run a 4" supply to the room
- is it a simple matter of installing the duct from the main trunk to the room.
- there is an existing 4" duct to a bathroom beside the bonus room. would it be acceptable to run a larger supply to this vent and split off it to the bonus room?
- do i need to run a return all the way back to the main trunk? Or, there is an existing return in the bedroom next to the bonus room, can i connect the bonus return to this?

i dont need this room to be heated/ cooled like the rest of the living area. Id just like it not to be freezing in winter and like a sauna in summer. Its really just used for storage and closet space.

any input is appreciated.

Sounds like good solution would be a minisplit heat pump. Check out the mitisubishi Mr Slim on the web. These things are awesome for bonus rooms. I have installed about 80 of the mr slims without a factory defect. Cannot say the same for Daiken or LG but they are good products also IMHO.

[york_hvac]

We have a bonus room over our garage too. It doesn't get too hot in the summer but in the winter it is freezing. Our main AHU won't keep this room warm in the winter, even though the room next to it, not over the garage, can get pretty warm.
That being said, before spending any money on HVAC, make sure that there is adequate insulation, especially under the floor. If it doesn't get too hot/cold already, you might be able to use your existing system. However, depending on how much your existing system can do with the space, you may not even notice the difference.
Look into a mini-split heat pump. They're small and compact and are great for bonus rooms

[Cold Feet]

A mini split heat pump is the way to go for this. Both Daikin and Mitsubishi have equipment designed for large rooms.

If you're in a cold winter area (air temp regularly below 17), you'll need a mini split and base board heaters to provide backup heat in cold conditions. Heat pumps don't put out much heat in cold weather.