If you're building a home addition, you'll want to think about how you'll cool and heat the space. You should talk to an AC contractor for advice and make your decision before work on your addition begins. That way the system can be installed at the appropriate time as the room is built.
Possible options for cooling your new room addition include adding ducts to your existing HVAC, getting a bigger HVAC, adding a ductless heat pump, or using a portable air conditioner. Here's how these options compare.
Add Ducts For The New Addition
A simple solution would be to add the ducts needed to cool the new addition and use your existing HVAC unit. However, that's often not as easy as it sounds. Adding a new duct will draw air away that's intended to cool your home. Instead of chilling the addition, the end result could be that your entire home doesn't cool down very well.
An AC contractor needs to check the size of your HVAC and run tests to determine if a new duct can be added without affecting the rest of your home. If it can't, you'll need another way to cool the addition. That might include getting an entirely new HVAC so the AC contractor can pick the size for it and the new ducts needed to cool and heat your entire home properly.
Buy A Window Or Portable Air Conditioner
You might want to consider adding a window air conditioner or buying a unit that's on wheels and only needs to vent to the outside. These units are the least expensive, but you have to put up with an ugly window air conditioner or a portable unit that takes up space. It may depend on what you'll use the addition for.
You may still want to talk to an AC contractor to understand how adding a portable unit to your new room would affect how well the HVAC will cool the rest of your house.
Install A Heat Pump For Cooling And Heating
A ductless heat pump might be the best solution. You can add it to your room addition and control the temperature independently. Plus, a ductless heat pump can be used for more than one room, so if you've always been too hot in your bedroom, you might want to add extra cooling with the heat pump.
A heat pump doesn't even need ducts because the refrigerant lines pass through the wall to the blower that's mounted on the wall. You control the temperature of the room with a remote to keep it as cool as you like. An AC contractor can help you decide if a ductless heat pump is a good choice for your addition, and if so, they can install one for you.