In summer time the greatest issue may not be the heat but the humidity. Increased humidity can lead to serious damage in the house like warped wood floors, furniture, chipped paint, wet stains on the walls and ceilings and in many cases foul smells.
Humidity should be between 35% and 50% so that the house and its inhabitants are comfortable and healthy.
The air conditioner is often used to lower the humidity level but this is not recommended because lowering the temperature in the room will make the temperature of the furniture drop thus increasing the probability of condensation. Nowadays, the air conditioner has a feature that will safely reduce the humidity in the house.
Dehumidifiers can reduce the moisture level in a house by up to 90%. Whole house dehumidifiers maintain the moisture level low automatic and can be set to do so in a particular room if needed. The dehumidifier will also make the room air more pleasant thus decreasing the need for an air conditioner and reducing the energy bill.
A whole house dehumidifier must be emptied of water annually, unlike the portable dehumidifier fit for a single room that needs frequent maintenance.
To prevent high levels of humidity in the house you can also clean and repair the roof gutters, avoid venting any appliances like dryers and stoves in the attic, make sure ground slopes near the house foundation are fixed to avoid rainwater building up and depositing near the house foundation. You can use downspout extenders for the gutters to guide the water away from the house. Seal holes around the wiring and plumbing system and any other unwanted air leaks that may increase the chance humidity seeping in.