Your home’s second floor never seems to get cool enough in summer. This is a common problem, even in Northern California. You may often find yourself wondering how to make it cooler upstairs.
Could it be that one air conditioner isn’t enough? That’s a striking thought, since you’ve already invested in an AC unit you thought was big enough for your entire home. But if you’re making the downstairs colder to make the second floor just barely comfortable, this is neither practical nor efficient.
Believe it or not, having two air conditioners may be more energy-efficient than having only one. An upstairs AC unit can reduce the workload on your main HVAC system. In many cases, ductless mini-split systems offer an efficient, flexible solution for hard-to-cool spaces like second floors. We’ll look at why a single air conditioner is often ineffective for a multi-story home, how adding another one can help, and alternative upgrades to consider.
Why a Single AC Unit Often Doesn’t Cool Upstairs Rooms Effectively
A single unit can be overworked in a two-story home for the following reasons:
- Hot Air Naturally Rises: As your air conditioner cools the first floor, warmer air rises, with nowhere to go but the second story. This effect is enhanced during the peak summer months. Meanwhile, cool air sinks, which makes the unit work harder to push it upward. If the AC is blowing hot air, troubleshoot the issue or call a repair professional immediately.
- One Thermostat for Your Entire House: If the thermostat is on the first floor, it will not read the temperatures upstairs. Any adjustments it makes to your cooling system are based on the temperature at ground level. Therefore, your AC may turn off when the first floor is cool enough, but anyone above you will be sweating.
- Inadequate Insulation: A lack of insulation in the attic and upper floor allows heat into your home. Heat absorption from the roof can also make the second floor too hot. Consider making improvements if you don’t see insulation in your attic, rim joists are exposed, or existing materials are deteriorating.
- Ductwork: Air ducts are prone to leakage, especially as they age or if they’re not properly serviced or designed. If this is an issue, air may blow from first first-floor vents but not from the second-floor vents. Aside from damaged ducts, this can also be due to an undersized AC system.
- Air Leaks in Your Home: Cool air doesn’t only leak from ductwork. Tiny holes, cracks, and spaces in walls, especially around door and window frames and where utility connections enter your home, can let in hot air. The heat then rises to the second floor, unless these leaks are sealed with weather stripping, caulking, or spray foam insulation.
These issues can not only make your air conditioner less efficient. They can also cause strain that leads to major damage and problems, such as the outside AC unit not running.
Benefits of Adding a Second AC Unit for Upstairs
Having a separate upstairs AC unit can have many benefits, especially if your second floor never seems to stay cool. If you’re concerned about it being an extra expense, here are a few advantages of having a second air conditioner or a ductless mini-split system installed by one of our professionals:
- Increased Cooling Power: Add a second AC unit or a mini-split unit, and you can get an equal amount of cool air to the second story. Like with your first unit, the air handler and condensing unit should be centrally located to improve efficiency, avoid long runs of ductwork, and simplify maintenance. Alternatively, a mini-split system allows room-by-room cooling without extending ductwork, which is ideal for retrofits or older homes with limited space.
- Reduced Energy Consumption: You can avoid overworking a single AC. Having two units also enables you to shut off an upstairs system when the space is unoccupied. Not cooling your entire home at once can keep your utility bills in check.
- Cost Savings: Installing a second air conditioner is an upfront investment. However, each unit won’t need to cool as much square footage. Combined with the option to turn one or the other off when not in use, this can result in long-term savings that can offset some of the installation cost.
- Back-Up Air Conditioner: An upstairs AC unit can serve as a backup if the primary air conditioner doesn’t turn on. It will continue to keep part of your home cool and, since cool air sinks, provide some temperature control for downstairs.
- Less Strain on Your Primary AC Unit: Your downstairs cooling system won’t have to run as long. It’s also less likely you’ll turn down the setting to cool your entire home. Therefore, the chances of pushing the first-floor unit to its limit are lower.
Two air conditioners can deliver more consistent, comfortable indoor air temperatures during the peak heating season. However, regardless of size and layout, your home must be properly insulated and ventilated to achieve optimal HVAC performance. Consider improving insulation in the attic, roof, walls, floors, and ductwork before moving forward with your upgrade, so that your investment pays off.
Other Smart Upgrades to Keep Your Upstairs Space Cool
Installing a second central air conditioner can seem like a daunting project to take on. But it’s not the only way to make it cooler upstairs. At Calvey Heating and Air, we can install ductless mini-splits and air purifiers, which can help improve comfort upstairs. Here’s a look at a few smart upgrades to consider if adding another central cooling unit isn’t desirable or feasible:
- Ductless Mini Split System: A mini split air conditioner does not require ductwork. Ideal for cooling a smaller space, the unit is often wall-mounted, so it’s out of the way. You can also connect multiple units to a single compressor to have zoned temperature control in different upstairs rooms.
- Zoning: You can upgrade your existing setup with a zoning system. It requires installing dampers inside the ductwork (rather than closing vents in an unzoned system, which can strain it). Dampers work by directing cool air to specific sections of your home or individual rooms.
- Smart Thermostat: A modern thermostat can learn your habits and create a schedule around them. Depending on the model, it may detect occupancy and automatically turn off cooling when no one is in a room. It can make a single zoned system more energy efficient.
- Air Purifiers: Air purifiers filter airborne particles to improve indoor air quality. These same particles can make your HVAC system less effective, so removing them can improve performance and allow more cool air to reach the second floor, whether you have an upstairs AC unit or not.
- Ventilation Improvements: Effective ventilation solutions include exhaust fans for removing moisture from bathrooms and kitchens. They remove humidity that can strain the system. Other options include attic fans or ridge vents for letting hot air escape. You can also install a whole-house ventilation system to improve air quality and temperature control.
Is It Time to Install a Separate AC Unit for the Second Floor?
Any HVAC upgrade is a big decision. Therefore, you must consider whether a separate AC unit for upstairs is really necessary. If there are cooling issues, make sure to clean or replace air filters, keep vents open and unblocked, and close blinds and curtains so sunlight doesn’t add extra heat.
However, if you’ve done all these things plus made improvements to insulation and ventilation, and it’s still too warm, it may be time to consider an upstairs AC unit. Our experienced technicians can determine if you could benefit from one. They can also help you make an informed decision on the best system for your home.
If you’re adding a second AC unit, important considerations include capacity, which is largely determined by square footage (and other factors), and whether your electrical system can support it (you may need a dedicated circuit or electrical panel upgrade). Placement is also important. Indoor units should be centrally located, while outdoor units are best placed out of direct sunlight and where noise won’t be a concern.
Calvey Can Help Make It Cooler Upstairs
Whether your existing HVAC system needs improvements or you want a separate AC unit for upstairs, our experienced air conditioning installation team can help. We provide energy-efficient cooling systems, including central units and ductless mini splits, in San Jose and the surrounding areas. Contact us today for advice or to schedule an appointment.