Chill Out, Fans!

Remember when Terry came last summer to do this?

Well…his work wasn’t quite finished. Now that we built the second story office, Terry returned to install more tubing over the sub-floor.

The entire first floor is concrete, which was poured directly over the pex tubing. The office floor, however, will be wood. We made a zig zag pattern with plywood strips for the pex to lay in. That way the pex sits below the surface, so the wood flooring will lay flat over everything. The tubing was covered with aluminum plates for heat conduction into the flooring.

Although we’re still missing some key components of the heating system, like the boiler and heat pump, Terry set up the manifold. But first, we finished another wall in the mechanical room and put up more diamond plate.

The super colorful manifold controls the water flow in the floors. Why is it so large? If there was one giant maze of tubing under the floor, it would mean the water would have to travel a longer distance, making it less efficient to heat the floor. So, the tubing is divided into many smaller loops (less distance for the water to travel, less thermal loss, more uniform heating). We shouldn’t need to mess with this beautiful beast once it is operating.

That was the final installment of tubes for the radiant heat system, our primary heat source. Now what about cooling?

We opted for electric fan coils (white boxes in the photos below). Fan coils aren’t very common, but they seemed like the best choice for our small space. Their name best describes them – cold water runs through them and a fan blows cold air into the room. The same heat pump we’re using for our radiant heat system can also be used to make cold water for the fan coils. The water lines are also the same type of pex tubing we used in the floors. Fan coils are energy-efficient and great for small spaces since they don’t require ducting. Plus, they are quiet and less obtrusive than a mini-split, a nice selling point.

The fan coils will be recessed in the walls, although still visible. We test fit the fan coils and built mounts for them. They will look much better after the drywall.

We got a small unit for the office that sits inside the partial wall.

A larger fan coil will cool the entire kitchen/living room area.

Perhaps the most exciting unit is the small one we got for the bedroom. Our current house doesn’t have an AC duct in the master bedroom (don’t worry- the guest bedroom does). No matter how much we blast the AC in the rest of the house, things can get pretty hot in the bedroom, especially in the summer. This fan coil is ceiling-mounted and fits inside the wall above the closet door.

Although the water lines are much easier to install than ducts due to their small diameter and flexibility, it wasn’t a cake walk. Sam and Aiden drilled a lot more holes through the framing. The cold water lines had to be insulated with foam pool noodles, making them more difficult to pull. Sam and Aiden were extra careful not to snag the delicate foam tubes. If there is a tiny hole in the foam, condensation can leak out into the walls.

We also ran rigid condensate pipes from the fan coils back to the drain in the mechanical room. The walls are getting very crowded!

In other news, the weather finally warmed up enough for us to camp out on the living room floor!