Five Benefits Of Ductless Heating On Third Floors And AtticsA finished attic or full third floor feels like a bonus on your home! You can make it an extra bedroom, home office, teenager’s room, or extra rec room without feeling like you’re taking space from the rest of the house. We’ve even seen larger spaces get turned into beautiful master suites.

However, the drawback can be not having heating or cooling all the way up there. If you have an older or historic home out in, say, Boise Hills, the third floor may not have any ductwork leading to it. 

Even with an older home in Donnelley, or new construction near McCall, you could have ductwork but weak airflow. That happens because the air has to travel so far from the furnace. It loses pressure along the way. 

Fortunately, there’s an excellent way to make your third floor, dormer, or finished attic just as comfortable as the rest of the home — maybe even more comfortable! And, it won’t affect your electric bill all that much. 

We’re talking about ductless heating and cooling, or ductless mini splits. You can choose to outfit your entire home with this system. Or address just one room in the house. Or anything in between.

If you’re not familiar with these systems, you can read about how they work here. And, find out how they might look in your house here.

For this article, we’re focusing on the advantages of ductless heating and cooling for third floors, dormers, and attics in particular. The six biggest benefits are: 

  1. “Zoned” Comfort
  2. Whisper-Quiet
  3. No Need to Add Ductwork
  4. Fast, Easy Installation
  5. Energy-Efficient
  6. Ductless Heating and Cooling In Boise, ID

If you’d like to learn more about ductless mini splits and how they would work in your Treasure Valley home, download our free product guide below. Or call or email us here at Snowflake Air for a free consultation!

“Zoned” Comfort

Zoned Heating And Cooling Allows For Energy Saving, And Preferred Temperatures In Every Room

“Zoned” heating and cooling is when the room or “zone” you’re addressing has a thermostat operating independently from the rest of the house. For third floors, this is crucial. The temperature up there is very different than on the first floor. 

Even if you have ductwork on the top story, you’ll never get enough heating and cooling. The thermostat on the first floor reaches its call before the dormer or attic gets the right treatment. 

With ductless, you get an air handler with a built-in thermostat. It runs based on the room temperature where you install it — not based on what’s happening on the other side of the house. 

Read More: How Much Does A Mini Split Cost for Homes in Boise, ID and Valley County?


For a smaller dormer, peace and quiet can go a long way. If you’ve used window air conditioners up there in the past, you won’t believe your ears when you hear (or don’t hear) the difference! 

Mitsubishi indoor units produce up to 30 decibels of sound. And that’s when they’re on full blast (which isn’t all that often). 

To put it in perspective, that’s somewhere between rustling leaves and people whispering. Meanwhile, the softest window ac is close to 40 decibels, with most up around 50. And, loudness doubles every 10 dB. 

Read More: How Do Mini Splits Work?

No Need to Add Ductwork

This one’s important: No new ductwork! That saves you a ton of money. Adding ductwork starts with at least $300 for design and diagnostics. Then, it’s $250 or more per run (you need a vent and then a return). 

That’s not even considering the walls we’ll rip through and space we’ll take up on the third floor to get the ductwork in there. All told, it’s well over $1,000 just for this part of the job. 

And, it won’t even work that well. If your home and system weren’t designed to circulate air that far, you’ll get very weak airflow up there.

By contrast, installing a mini split is fast and easy. And, you don’t worry about ductwork because the system only moves heat, not air. Here’s how that works: 

Fast, Easy Installation

We can install a single-zone ductless mini split in one day. And, that’s usually all you need for a third floor or dormer. If it’s one big room, a single unit does the trick. 

With ductless, your air handler draws in the air from the room. Then, a refrigerant liquid inside the system heats or cools it. That liquid travels in a closed loop between the indoor unit and the heat pump outside. 

In other words: you don’t need ducts to move the air. So, you don’t need to clear out a lot of space. 

Read Real Case Studies Of Mini Split Installations In Boise Metro and Valley County

Instead, we mount the air handler inside and do the same outside with the heat pump. All we need to connect the two is a lineset that’s a few inches in diameter. 

For an attic or third floor, we run it right through the wall and down the side of the house. You’ll barely notice anything inside because all you see is the wall-mounted unit. Outside, it looks like a gutter. 


Mini splits are incredibly energy-efficient. They use a small fraction of what your average furnace or AC requires. So, you’ll add heat and cooling to your third floor. But, unlike baseboard heating, a mini split won’t add much, if anything, to your electric bill. And, you can get money back on your installation.

Read More: Rebates and Financing Options For Treasure Valley Heat Pump and Mini Split Installations

Ductless Heating and Cooling In Boise, ID

As a Mitsubishi Diamond Dealer, Snowflake Air is your local expert for all things ductless! We believe mini splits are the best heating and cooling options out there today, and we’ve got a long list of satisfied homeowners in the greater Boise, ID area to prove our point. If you’d like to learn more, download our free product guide. Or, click below or call (208) 205-9078 for your free consultation.