The most effective way to cool a poorly insulated home is by actively keeping heat out during the day and letting cooled outside air in at night. Combine that with targeted ventilation and sun shading, and you will soon notice a pleasant difference. Do you want structural improvement? Then architectural interventions are the next step. In this article, we answer the most frequently asked questions about cooling in the summer.

Why does a poorly insulated home heat up so quickly?

A poorly insulated home heats up quickly because heat flows in virtually unhindered through walls, roofs, windows, and floors. Without an insulation layer, the building envelope acts like a sponge that absorbs solar heat and transfers it to the indoor air. In addition, concrete and stone store heat during the day and gradually release it in the evening.

The biggest culprits are:

Single glazing or poorly insulating windows that let through direct sunlight and heat radiation
Flat or dark roofs which heat up enormously in the full sun
Uninsulated cavity walls store that heat and slowly dissipate it inwards
Few or no ventilation options whereby heated air cannot escape

The result is a home that quickly becomes unpleasantly warm during the day and cools down only slowly at night. It is precisely this slow cooling that makes poorly insulated homes so uncomfortable during hot summers.

Which free methods help keep heat out?

The most effective free methods are closing windows and curtains on the sunny side as soon as the outside temperature exceeds the inside temperature, and opening windows on the shaded side for ventilation. External sun shading works significantly better than internal curtains or shutters in this regard.

Practical tips you can apply immediately:

Close windows and shutters on the side facing the rising and high sun early in the morning.
Hang light-colored curtains or reflective film on windows that catch the sun.
Turn off heat sources such as ovens, dryers, and computers when not necessary.
Use LED lighting instead of incandescent bulbs, which produce much less heat.
Place plants in front of south-facing windows as a temporary source of shade.

These measures cost nothing but do require discipline: it is a daily rhythm of opening and closing at the right times.

What is the difference between a fan and an air conditioner for cooling?

A fan does not actually cool the air, but makes your skin feel cooler because moving air accelerates the evaporation of sweat. An air conditioner lowers the actual air temperature in a room by actively venting heat to the outside. At temperatures above 35 degrees, a fan only offers comfort if the air is already somewhat cool.

The difference in practice:

Fan: Cheap to purchase, low energy consumption, but no real temperature reduction. Effective down to approximately 32 degrees outside temperature.
Air conditioner: lowers the actual room temperature, ideal during extreme heat, but requires a higher investment and installation. A mobile unit does not need to be permanently mounted, whereas a split-unit does.

For anyone seriously considering purchasing an air conditioner, it is wise to compare carefully beforehand based on capacity, energy label, and the type of room that needs to be cooled. You can use a air conditioning selection guide use to make the right choice for your situation.

How do you use night ventilation effectively?

Night ventilation works by actively allowing cool outside air to flow through the home at night, so that the heat stored in the walls and floors during the day is dissipated. To do this, open windows on opposite sides of the house to create a draft. Close everything again early in the morning before the outside temperature rises.

For best results:

Start ventilating as soon as the outside temperature drops below the inside temperature, often around 22:00 PM.
Open windows on the ground floor and the upper floor simultaneously for a chimney effect
Use a fan to boost the airflow when there is little wind.
Close windows and curtains again before 08:00 AM to retain the cool air.

Night ventilation is one of the most underestimated techniques in warm weather. In a home with sufficient ventilation openings, the indoor temperature can remain several degrees lower than during the day without any technical installation.

Which structural interventions improve cooling?

Structural improvement of cooling in a poorly insulated home requires architectural interventions that reduce heat absorption or increase ventilation options. Examples include roof insulation, ventilation grilles, external sun shading, and the creation of additional openings for airflow.

The most impactful interventions listed:

Roof insulation: The roof is responsible for a large part of the heat gain in the summer. Insulation keeps heat out and cold in.
Exterior sun shading: External screens, awnings, or roller shutters keep up to 80 percent of the sun's heat out.
Additional ventilation grilles or ducts: More openings in walls or roofs ensure better air circulation, which slows down heat buildup.
High-efficiency glass or solar control glass: Replacing old glass significantly reduces heat transfer.

Do you want to know what a structural intervention costs in your situation? Via the pricing tool You will quickly receive an indication of the costs for specific work.

Can drilling concrete help improve ventilation in the home?

Yes, drilling into concrete can directly contribute to better ventilation in your home. By drilling holes in concrete walls or floors, ventilation grilles, penetrations for ventilation pipes, or openings for an air conditioning system can be installed. This is often the only way to create additional ventilation options in a solid concrete or stone home without major demolition work.

Applications where concrete drilling improves ventilation:

Installing a through-hole for a split unit air conditioning through a concrete outer wall
Installing ventilation grilles in basements or crawl spaces for better air circulation
Drilling penetrations for mechanical ventilation (HRV systems)
Laying trenches for ventilation system pipes in shell or occupied situations

The advantage of drilling over chiseling is that the surrounding structure remains intact and the workplace is minimally damaged. Diamond core drills ensure a precise, dust-free opening to the desired diameter.

How De Betonboorder helps with cooling and ventilation in the home

Do you want to have an air conditioner installed, a ventilation system connected, or additional through-holes made in concrete walls? We take care of the drilling work from start to finish, neatly and professionally. This is what we can do for you:

Drilling through-holes for air conditioning units in concrete, stone, and even steel
Milling of trenches for ventilation system pipes in both shell and occupied situations
Installing ventilation grilles in basements and crawl spaces
Work throughout the country with a nationwide network of experienced professionals
In many cases on-site within two working days, with contact within 24 hours.

We ensure that the workplace is left neat and tidy afterwards. Curious what we can do for your situation? Contact us and we look for the best solution together.

How do you cool a poorly insulated home in the summer?