How to keep cool on hot days

Adequate pro­tec­tion of homes and work­places against the increas­ing sum­mer heat is of key import­ance for our well-being and health. Our expert will tell you what steps you can take to keep your home at a com­fort­able tem­per­at­ure and ensure a healthy liv­ing envir­on­ment.

Tip 1: Use fans and air conditioners only for short periods

When you need to quickly cool down over­heated rooms, fans or mobile air con­di­tion­ers are often the go-to solu­tion. Although these devices provide a cer­tain cool­ing effect, you should use them only for short peri­ods, as they often cause colds and muscle ten­sion – not to men­tion the high energy con­sump­tion of these appli­ances.

Tip 2: Architecture tailored to your needs

There are more effect­ive ways to pro­tect interi­or spaces from over­heat­ing. Let’s first focus on the archi­tec­ture. Avoid large, glass-covered facades and ensure an appro­pri­ate ceil­ing height. The ceil­ing height should take both cri­ter­ia – namely room light­ing and room heat­ing – into account. While high ceil­ings and large win­dows provide plenty of nat­ur­al light, they also sig­ni­fic­antly increase the input of heat dur­ing the sum­mer months. There­fore, a com­prom­ise should always be sought. If the win­dow pro­por­tion of the facade accounts for less than 20 per­cent, sol­ar shad­ing – which usu­ally con­sti­tutes a clas­sic thermal bridge – is unne­ces­sary. Nev­er­the­less, good nat­ur­al light­ing is achieved. If you still want to go for large glass sur­faces, make sure there is a suf­fi­ciently dimen­sioned roof over­hang. In sum­mer, when the sun is high in the sky, the over­hang helps to keep the heat out­side. The low angle of the winter sun, by con­trast, can gen­er­ate sol­ar heat gains inside. You can achieve a sim­il­ar effect with bal­conies. In addi­tion, or as an altern­at­ive, you can use spe­cial sun pro­tec­tion meas­ures to ensure that indoor spaces remain at a com­fort­able tem­per­at­ure dur­ing the sum­mer months. Roller shut­ters, Vene­tian blinds, fold­ing shut­ters or awn­ings pro­tect from excess­ive sun­light. This is par­tic­u­larly import­ant for roof win­dows or sky­lights. You can con­veni­ently raise and lower exter­i­or shad­ing devices using motor­ized drives and auto­mat­ic timers. Mod­ern sol­ar-powered drives also help save elec­tri­city.

Tip 3: Look for high-quality windows and benefit from innovations

As a gen­er­al rule, win­dow frames and fixed glaz­ing should have good insu­la­tion prop­er­ties. Keep in mind that the insu­la­tion value of the glass is not the same as that of the entire win­dow assembly. Mod­ern win­dows are highly com­plex sys­tems that con­sist of mul­tiple com­pon­ents. Wheth­er installed in new-builds or used for repla­cing win­dows in exist­ing build­ings: win­dows with triple glaz­ing and good insu­la­tion prop­er­ties are stand­ard today. In addi­tion, you have the option of installing spe­cial sol­ar con­trol glass. An innov­at­ive solu­tion is so-called “smart glass” (or switch­able glass), which changes from clear to tin­ted with­in a few minutes while main­tain­ing trans­par­ency. Coat­ing glass panes with a spe­cial film can also help pre­vent excess­ive heat buildup.

Tip 4: Well-insulated building envelope and adequate ventilation

Fur­ther­more, a well-insu­lated build­ing envel­ope can help avoid heat stress. Insu­lat­ing the facade and the roof has a pos­it­ive effect on the indoor cli­mate – provided there is suf­fi­cient vent­il­a­tion. This can be achieved either manu­ally or through a con­trolled res­id­en­tial vent­il­a­tion sys­tem that ensures an auto­mat­ic exchange of indoor air. When vent­il­at­ing manu­ally, make sure to provide good cross-vent­il­a­­tion on hot days, espe­cially at night and in the early morn­ing hours.