Every year, from roughly the first week of July, the wine calls start. The room held its set point through spring without complaint and now it sits four degrees high all afternoon and recovers overnight. Nine times in ten the cooling unit is working exactly as designed.
A cellar unit is sized against a load, not a room
Sizing depends on the volume, the insulation, the glass, the lighting and, critically, the temperature on the other side of every wall. A room built inside a conditioned house has a mild load. A room sharing a wall with a garage, an attic knee wall or an exterior brick face in Houston does not, and in August that difference is enormous.
So a unit specified against a January site visit and never checked against a summer one will cool the room for eight months and lose it for four. That is a commissioning problem rather than a problem, and no amount of servicing the head will fix it.
Where the heat is actually going
Split and ducted systems reject their heat somewhere, and that somewhere has to be able to take it. We regularly find condensing sections discharging into a sealed closet, an attic space with no ventilation, or a utility room that reaches 105 degrees by mid-afternoon. The unit is then trying to reject heat into air hotter than the air it is cooling, and it will simply stop keeping up.
The things that are genuine problems
- A condenser packed with dust. Same as any refrigeration, and the first thing checked.
- Low refrigerant. Real, and it means a leak that has to be found rather than topped up.
- A failed evaporator fan. Cold made and not moved.
- A sensor reading its own housing. The display says 55 and the rack says 61. We put an independent probe in before believing any front panel.
What you should do about a few degrees
Over a weekend, nothing. Over a Houston summer, quite a lot: heat is cumulative and a collection held at 60 for four months a year ages faster than the same bottles held at 55. Steady drift is worth a visit before it becomes the way the room simply behaves.
We take on systems other people installed, and we will tell you plainly if the unit was undersized or badly sited to begin with. Call (844) 398-4960.
