How Honest Fix Installs an Evaporator Coil

It is where your home's heat leaves the air. Warm indoor air passes over the cold coil, gives up its heat to the refrigerant inside it, and the moisture in that air condenses on the coil and drips into the drain. The coil sits on top of the furnace, or inside an air handler, and it is the indoor half of the cooling cycle.

Yes, in most homes it can, and how the two are fitted together is what decides whether it was done well. If the coil and the furnace are different sizes, a gradual transition is built between them so the airflow is not pinched where they meet. Where there is no room for a transition, the coil is set to overhang on coil types that allow it, or a wider furnace is blanked off, and Honest Fix avoids that whenever it can. A coil that just gets dropped on a mismatched furnace is an avoidable problem.

Because there is a drain pan and a refrigerant coil inside it, and both are easy to hit. A screw driven into the pan makes a slow leak that does not show up for months; a screw into the coil leaks refrigerant and takes the system down. Honest Fix places every fastener with that in mind, which is the kind of thing you only notice when it was done wrong.

Because they are two separate cabinets, and once in a while they are two different widths. Where there is room, a gradual transition is built between them so the air is not pinched at the joint. Where there is not, the fit is still made on purpose: on coil types that allow it the coil is set to overhang the furnace below it, and where the furnace is the wider of the two, the difference is blanked off so air cannot slip past the coil instead of going through it. What you should not see is a coil sitting on a cabinet it does not match with the gap simply left open.

It sits in the secondary drain port and shuts the system down if the drain backs up, before the water can overflow into the furnace below it. On a coil sitting directly on a furnace, a plugged drain with no switch sends water straight into the equipment, so the switch protects both the ceiling and the furnace.

The coil and its metering device are heat-sensitive, and they sit right at the joints being brazed. Wet rags on both the liquid and suction lines act as a heat sink, with a heat-blocking product added where a joint needs more protection, so the heat is pulled away from the bulb and the TXV while the joint still gets hot enough to braze correctly. The rubber grommet around the line is taken off first so the torch does not melt it, then put back when the job is done.

More of it is visible than you would think. Look at the seam where the coil meets the furnace: it should be a built transition or a deliberate fit, not a gap somebody left. Look for the safety switch in the secondary drain port, and, if your coil went into an existing plenum, for a door you could actually open. The brazing and the fasteners inside the cabinet are the parts nobody can inspect afterward, which is why they are written down here instead. If you would rather have someone look with you, that is what a free exact quote visit is for.