Mini Split Installation in Florissant, MO
A new system here will heat from October through April and cool from May through September every year. Tell us about the house, and a licensed contractor who covers St. Louis County will get in touch.
Tell us about the job
It takes about a minute.
Florissant asks a mini-split to work most of the year
Winter nights here average 26°F, and homes need heat from October through April. That is seven months of the year on the heating side alone, and with summer cooling running May through September, a mini-split in Florissant is doing one job or the other for all twelve months. Only a short stretch in spring and fall gives it a break.
A new unit has to be sized for both ends of that range, the 26°F nights and the 87°F afternoons, not just one season. Any mini-split heat pump built since January 2023 has to meet 14.3 SEER2 for cooling and 7.5 HSPF2 for heating, so that baseline is set. What matters for your home is picking the right size and installing it so it holds up through all seven months of heating and five of cooling, year after year.
- 7 months
- October through April, your system heats
- 5 months
- May through September, it cools
- 26°F
- the average winter night it heats against
- 87°F
- the average summer afternoon it cools against
NOAA nClimDiv, 1991–2020 normals
- Is a mini split worth it?
- For most homes here, yes, especially in a room that never gets comfortable off the main system. A mini split puts heat or cooling right where you need it, so it earns its keep in additions, garages turned into living space, or bedrooms that run hot in summer and cold in winter. Florissant needs heat from October through April and cooling from May through September, so a mini split here is working nearly the whole year instead of sitting idle most of it.
- How many rooms can a mini split cover?
- A single indoor head is sized for one room or one open area, but a multi-zone system can run several indoor heads off one outdoor unit. Each head has its own thermostat, so every room it serves can run at a different temperature at the same time. A contractor will size the system to the square footage and layout of the specific rooms.
- Can a mini split heat a whole house?
- A mini split can heat a whole house if it's sized and placed for that job, but this takes real planning, not just extra indoor heads. Winter nights here average 26°F, so the outdoor unit and every zone need to be matched to that cold rather than to a mild-climate spec sheet. Most homes here still heat with gas, and a contractor can lay out whether a full mini-split system or a mix with the existing furnace makes more sense for the house.