The Hot Room

It's no secret that the previous heating and cooling system was not working for us.  We needed a solution to adequately heat and cool this new space so that it was comfortable year round.



We did a lot of research, had several different companies in, and came out with a two options (and a variety of prices).  So we had to decide which would be best for ourselves.  Here's what we narrowed our options down to:

1) Run ductwork from our current HVAC system (gas furnace and central air) through the basement walls and under the floor boards.  This solution is our number one choice, we just didn't know if it's possible.

2) Mini-split system.  You  might be familiar with this giant.  This is a heating and cooling system that mounts on the wall and has a separate condenser unit that sits outside.  It can both heat and cool using the same unit.

Retrofit New Ductwork (to tie into current gas furnace and central air system)
Immediate Cost: $800
Future Cost: $3,500 - $4,500

Pros
1) One system to update, one system to fail: Since our whole house would be tied into the same gas furnace and central air system, we would only have one system to maintain (and replace) when the time comes

2) Constant temperature throughout the house. 

3) Cosmetically the most pleasing (will only have one air return grille and 3 floor heat registers)

4) Lower operating cost in the winter

Cons
1) Ability to run vents through exterior walls. We don't want any structural issues in the future so we are really looking into this

2) Long run of venting that is far from the gas furnace. This means that the moving air might not be enough to adequately push the hot or cold air to the room.  We can add a booster fan thing, but this would cost additional money.

3) Upgrade our gas furnace and central air to a larger unit.  Currently, our furnace and AC are heating and cooling a 1,600 square foot space.  This room brings our house up to a 2,000 square foot space that needs to be heated and cooled.  So we require a larger unit.


Mini-Split System
Immediate Cost: $3,500
Future Cost: $3,500

Pros
1) Heat and cool the space adequately and efficiently

2) Flexibility to set this room at a different temperature than the rest of the house

3) Quick and easy installation

Cons
1) Expensive to acquire

2) Operating cost - electricity costs more vs. gas

3) Large, ugly unit that sits on wall (we considered covering the unit with a decorative wooden box, but discovered that this voids the warranty)

4) Requires dedicated electric circuit

5) Condenser unit sits outside and must be elevated and kept free of ice.  The unit is rated to operate to -15F degrees.  If ice builds up on the unit, it could freeze, so we would have to actively keep it free of ice and snow.

6) Two HVAC units to fail and replace

7) We still need to update our gas furnace at a later time (it's 18 years old)

We considered the mini-split system because it's the only solid alternative for heating and cooling this space with out retrofitting the room to work with our current ductwork.

Running new ductwork to tie this room into our current forced air system would be the best option. This is Plan A because the basement wall is accessible through the bottom 13" of the current wall with the French doors.



After talking to 4 different HVAC companies and hearing 4 different professional opinions, we just had to go with our gut.

 

Quotes to run new ductwork through the basement wall and under the new floor ranged from $650 - $2,000.  And all four quotes had different installation plans.   Because we are dealing with what used to be an exterior wall, we were very concerned about compromising the structural integrity of the house.  One quote included notching the floor joists to run the ductwork through the basement wall.  The company assured us that they notch floor joists "all the time" (which doesn't mean it's right).

Now I'm not a professional, so I rely on google searches and asking the pros...  According to my research, only 1/6th of the supporting joist can be notched without any concern (the company wanted to notch 1/3rd of the joist).  Our gut was saying DO NOT NOTCH THE FLOOR JOIST SUPPORTING YOUR HOUSE.



We had one young contractor who thought he could run the new ductwork with out notching the floor joists in our basement.  This was all we had to hear in order to ditch the idea of the mini-split system. 


 

He didn't notch a joist, but it meant that he would have to install a custom vent with an elbow to go under the joist and then through the wall.  The cost would be the same, but anytime an elbow is used in HVAC venting, the air tumbles and doesn't get pushed out at a perfect rate. It's one sacrifice we had to make.

 

We still need to update our furnace, but this is something we can do this down the road.  Our current gas furnace will suffice for now. We are well aware that the extra square footage will stress the current system, and we feel we have weeks before it goes.  But if we can squeeze one more week out of it, why not?

Now that the ductwork is ran, we can close up the floor and continue with the fun.