Is there a reason why a top-floor apartment is much hotter than the one on the ground?
You know that hot air rises, and the roof of the top-floor apartment gets the sun, but does that make a top-floor apartment hotter?
The simple answer is that a top-floor apartment is usually 4-5 degrees warmer than a lower-floor apartment unless you take steps to reduce the impact of hot air rising and the effect of the sun on the roof.
1. Why Do Top Floor Apartments Get Hot?
The primary reasons why top-floor apartments get hot are:
Hot Air Rises
One of the first principles you learn in science is that hot air rises above cold air. Without this action, we wouldn’t have the weather systems that make this planet habitable.
In an apartment block with people in their homes heating their apartments, the hot air rises unless blocked by insulation.
The effect is that the top apartment benefits from all the hot air generated in the flats below.
Passive Solar Heating
The top-floor apartment is closest to the roof, and the action of the sun on the roof may significantly raise the temperature inside the apartment.
In a high tower block, you are unlikely to benefit from shade, and you may get sun on the roof all day.
A solid concrete roof acts as a massive storage heater meaning your apartment stays hot overnight.
Your top-floor apartment may have window restrictors ensuring (for safety reasons) that you can’t open them too far.
If you can’t get air through your apartment, you can’t rely on a natural air change to keep your apartment cool.
2. What Is Too Hot?
Climate change news suggests that some areas may become too hot for human health. But the health implications are more complex than simple heat.
The issue about when your apartment becomes unbearable hot depends on humidity levels.
At 100% humidity, your body loses the ability to self-regulate at 95F. At 50% humidity, you get a bit more breathing room as things don’t get critical until 115F.
Overheating and resulting heat stroke can be fatal in humans and other mammals.
Ideally, your apartment temperature doesn’t exceed 80F to avoid extreme heat issues. The ideal temperature range for you to be comfortable ranges from 68 to 76F.
Individuals vary in how comfortable they are at any temperature and humidity level; the temperature you feel happiest depends on your gender, age, and activity levels.
3. What Are the Implications of Living In a Too Hot Apartment?
Ultimately living with excessive heat for months on end will shorten your life.
It seems an extreme outcome, but the human body is heat sensitive. Vulnerable humans like the young, elderly, and those with respiratory health conditions suffer more in the heat.
Living in hot rooms causes arrange of issues other than straight heat exhaustion.
You can expect:
- Lethargy – you are too hot and bothered to get up and move.
- Loss of focus – you can only think about being uncomfortable.
- Lack of sleep – because it is too hot to be comfortable, especially when it becomes hotter than the outside at night.
- Poor health – because of lack of sleep and lethargy.
- Disrupted body clock -can lead to severe illnesses like heart disease and diabetes.
- Prolonged high core temperature results in inflammatory disease.
- Increase in fungal infections because these thrive in hot moist conditions.
If the apartment is too hot, you may pay substantially more energy costs for cooling and washing than in cooler apartments.
4. How Can You Cool Down Your Hot Apartment?
An architect can suggest structural changes to your apartment to decrease the heat and reduce the reliance on expensive air conditioning.
But you may be limited in your architectural options if you don’t own the apartment or if the construction of the condo is solid concrete.
When a concrete block warms up, it acts as a storage heater which is why cities are hotter at night than the surrounding rural areas.
Architectural solutions include:
Redesigning the Airflow
Modifying your apartment to provide a better exchange of air to get the heat out of your apartment may offer a cooling effect.
You can go for a lower budget option by adding standing and ceiling fans, but having an architect work out the best options for circulating, pulling in, and venting hot air is more efficient.
Add a False Ceiling
The air trapped in the false ceiling is an insulating blanket, which means you get more value out of your air conditioning in the rooms below.
Although initially, you need to reroute utilities like plumbing and wiring, the suspended ceiling brings long-term benefits in future work.
You can hide most of your mechanical and electrical services in the suspended ceiling.
Insulate Floors and Walls
You want insulation that reflects heat away from your apartment.
Insulating the floor stops the heat from the apartments under you from rising into yours.
The walls may allow passive solar heating, so insulating them to reflect the heat may help reduce the interior temperature.
Reflective External Cladding
If you live in a hot climate, anything you can do to bounce the sun’s energy away from your home will help keep it cool.
You can get a range of cladding, and your architect will help you choose the most effective material while advising on other safety features like maintenance and fire safety.
If the sunlight falling on your apartment is heating it, you may want to consider if you can convert that solar energy into power to run your cooling system.
It seems fair that if the sun gives you problems, it is part of the solution.
You can replace your window glass with thermal glass to stop the heat coming through your windows.
This glazing option is expensive compared with standard window glass, and you may prefer to opt for a lower-budget application of thermal film to your existing window glass.
Anti-Heat Anti-UV Window Film
Mechanical solutions to your hot apartment include:
Cooling the Air
Reducing interior air temperature by running it through an air conditioning unit reduces the temperature inside your apartment.
You want to match the volume of air to the equipment. There is no benefit to having one that is too small or too large for your apartment.
Running an air conditioning unit requires a considerable input of energy, and typically shopping malls spend more money on cooling than heating.
Every hour you run your air conditioning unit costs.
Removing the Hot Air
If the air outside is colder than the air inside, then it makes sense to exchange the air.
It’s healthy to flush the air from your apartment and keep it fresh; if there is a significant temperature difference, you may want to pump cool air in from the outside and displace the hot inside air.
Get the Humidity Right
The heat in your apartment isn’t the only issue – the amount of moisture combined with the temperature can leave you feeling hotter and more uncomfortable.
You can increase your thermal comfort by adjusting your humidity levels.
Install a Heat Pump
Heat pumps are expensive to install but work in both directions for cooling and heating.
Once installed, their running costs are about 25% of conventional heating and cooling systems.
What you can do to modify your apartment depends on the Homeowners Association, apartment structure, and if you own or rent.
Some other options for helping to keep your apartment cool are lower cost and more DIY:
- Close the blinds to keep the heat out.
- Add green plants and interior water features to create a microclimate.
- Open the windows to force an air change.
- Wear light clothing.
- Add fans to your living space.
- Use low-energy lightbulbs – slight reduction in heat.
- Use hot appliances like ovens less or at cooler parts of the day – consider switching to microwaves or slow cookers.
In scorching weather, consider putting your sheets in the freezer or using an ice pack to cool your bed in the same way you use a hot water bottle to warm it.
The amount of money you want to invest in keeping your apartment cool will depend on ownership and available budget.
If you are renting, you may prefer to invest in a portable air conditioning system you can take with you rather than upgrading the landlord’s installation.
It may be more cost-effective for you to efficiently cool your bedroom to ensure a restful night than to try to keep the entire apartment cool.
5. How Much Does Average Air Conditioning Cost?
The cost of your air conditioning depends on:
- Equipment rating – more stars mean more efficiency and lower costs.
- Room size – the volume of air increases the cost.
- Cooling process – evaporative is less expensive but adds humidity.
Average prices for air conditioning range:
- Large rooms will take 70-95 cents per hour.
- Medium rooms will take 36-70 cents per hour.
- Small rooms take 25-35 cents per hour.
You can reduce your costs of air conditioning by:
- Only using it when you need it.
- Cooling to a comfortable temperature rather than the minimum.
- Use fans first and then air conditioning.
- Using appropriate size and efficiency.
- Regular maintenance.
- Choose an inverter unit for cost savings.
Although top-floor apartments are usually both hotter and colder than lower apartments, you can take steps to ensure thermal comfort without spending a fortune on air conditioning.
The best solution for you depends on your budget and property investment level.
Regardless of ownership, you may want to try a few DIY heat mitigation measures before investing in a more expensive solution.