Comparing Kalev and Rehau windows

PVC win­dows man­u­fac­tured by Kale­va and REHAU are among the top 10 most demand­ed on the mar­ket. Note that Kale­va is a Euro­pean man­u­fac­tur­er, and REHAU is a brand of a Ger­man com­pa­ny, part of whose pro­duc­tion facil­i­ties are also locat­ed in EU. Our experts have made an analy­sis of the advan­tages and dis­ad­van­tages of the prod­ucts of these com­pa­nies, which will help you make an informed choice.

First, we give a comparative table of the characteristics of the Kalev and Rehau windows

As can be seen from the table, the char­ac­ter­is­tics of the prod­ucts of both man­u­fac­tur­ers are almost the same, how­ev­er, the Rehau com­pa­ny pro­duces sev­er­al mod­els that are supe­ri­or in per­for­mance to the Kalev sys­tems.

Con­sid­er the impor­tance of each of the char­ac­ter­is­tics list­ed in the table for spe­cif­ic oper­at­ing con­di­tions of win­dows.

Profile class

This char­ac­ter­is­tic depends on the thick­ness of the pro­file and is clas­si­fied into two types — A and B. Class B prod­ucts have a wall thick­ness of less than 3 mm, class A prod­ucts — with a wall thick­ness of 3 mm or more. The wall thick­ness affects the strength of the entire struc­ture and the ther­mal insu­la­tion qual­i­ties. There­fore, the class B pro­file is used main­ly for the man­u­fac­ture of small-sized win­dows in the bud­get ver­sion, used for glaz­ing util­i­ty rooms. For glaz­ing res­i­den­tial and work­ing premis­es, it is nec­es­sary to use win­dows made of class A pro­file.

Kale­va and Rehau pro­duce win­dow sys­tems of both pro­file class­es.

Number of cameras

Win­dow frames are made of PVC pro­files that have a com­plex shape and form sev­er­al closed vol­umes in the sec­tion — cham­bers. The air enclosed in the cham­bers is a nat­ur­al heat and sound insu­la­tor, so the more cham­bers in the pro­file, the bet­ter the win­dow sys­tem will pro­tect against exter­nal noise and heat loss from the premis­es.

The num­ber of cam­eras in the sam­ples of the main mod­el range of Kalev and Rehau varies from 3 to 5. How­ev­er, the Ger­man com­pa­ny pro­duces one mod­el with 6 cam­eras.

Prod­ucts are select­ed accord­ing to the num­ber of cham­bers, depend­ing on the pur­pose of the room, the impor­tance of main­tain­ing the desired tem­per­a­ture in it, as well as on the cli­mat­ic con­di­tions of the region in which the con­struc­tion is car­ried out. For exam­ple, win­dows with 3‑chamber pro­files are suit­able for glaz­ing log­gias or bal­conies, 5‑chamber struc­tures should be installed for res­i­den­tial premis­es, for glaz­ing rooms in a build­ing built in the Far North, you can use the 6‑chamber Rehau sys­tem.

How­ev­er, it must be borne in mind that the abil­i­ty of a par­tic­u­lar mod­el to pro­tect against noise and heat loss depends not only on the num­ber of cham­bers, but also on oth­er char­ac­ter­is­tics — the width of the pro­file, the thick­ness of the dou­ble-glazed win­dow and the num­ber of seal­ing con­tours, which is gen­er­al­ly esti­mat­ed using the heat trans­fer resis­tance coef­fi­cient (KRT) . That is, it is pos­si­ble to choose a mod­el with a small­er num­ber of cham­bers, but with a large num­ber of seal­ing cir­cuits, which, accord­ing to the CST, will be supe­ri­or to a mod­el with a large num­ber of cham­bers and a small­er num­ber of seal­ing cir­cuits.

Number of sealing circuits

Seal­ing con­tours or in oth­er words — seal­ing inserts, which serve to tight­ly fit the sash­es to the frame, are made of high qual­i­ty rub­ber. The qual­i­ty of the rub­ber and the shape of the lin­er affect the life of the seals and the over­all abil­i­ty of the win­dow to pro­tect against noise, mois­ture and heat loss. Accord­ing to con­sumer reviews, the seals of the Ger­man com­pa­ny are of high­er qual­i­ty.

Dif­fer­ent mod­els of win­dows of the com­pared com­pa­nies are equipped with 2 and 3 seal­ing con­tours.

Profile reinforcement type

To give the win­dow greater strength, rigid­i­ty and resis­tance to tem­per­a­ture changes, PVC pro­files are addi­tion­al­ly rein­forced by insert­ing closed, U‑shaped or L‑shaped pro­files from a thin met­al sheet. Both man­u­fac­tur­ers use the same pro­files for rein­force­ment, but Rehau launched a mod­el with inno­v­a­tive poly­mer rein­force­ment, which sig­nif­i­cant­ly reduces the over­all weight of the prod­uct with­out los­ing strength.

Mounting width of the window unit

From the width of the win­dow block or in oth­er words — the depth of the pro­file, the noise and heat-insu­lat­ing prop­er­ties also depend. The Kale­va com­pa­ny pro­duces mod­els with a pro­file width in the range of 70–80 mm, Rehau — 60–86 mm. The mod­els of the Ger­man man­u­fac­tur­er are dis­tin­guished by a wide vari­ety in width, which allows you to select prod­ucts that are most suit­able for the spe­cif­ic cli­mat­ic con­di­tions of the region in which the con­struc­tion is car­ried out. For exam­ple, win­dows with a mount­ing width of 60 mm will bet­ter match the con­di­tions of the south­ern regions in terms of their heat-shield­ing qual­i­ties, a width of 70–80 mm for cen­tral Europe, with a pro­file width of 86 mm for the regions of the Far North.

Insulating glass thickness

A dou­ble-glazed win­dow is the main ele­ment of a win­dow, which occu­pies about 80% of its design area, there­fore, most of the heat from the room is lost through the dou­ble-glazed win­dow or a large pro­por­tion of noise from out­side pen­e­trates. In this regard, dou­ble-glazed win­dows are made air­tight — the design of a dou­ble-glazed win­dow con­sists of 2, 3 or even 4 glass­es, unit­ed by spac­ers of a cer­tain width, result­ing in one, two or three air cham­bers.

The Ger­man com­pa­ny uses dou­ble-glazed win­dows with a width of 35 to 53 mm, the Kale­va com­pa­ny uses a width of 40–54 mm. That is, Rehau prod­ucts have a wider range that allows you to select win­dows with thin­ner dou­ble-glazed win­dows for bud­get glaz­ing options or for instal­la­tion in build­ings locat­ed in south­ern regions, where ener­gy sav­ing require­ments are less strin­gent.

Heat transfer resistance coefficient

The heat trans­fer resis­tance coef­fi­cient or KST is an indi­ca­tor that is influ­enced by almost all para­me­ters of a par­tic­u­lar win­dow sys­tem: the num­ber of pro­file cham­bers, instal­la­tion width, thick­ness and num­ber of dou­ble-glazed unit cham­bers, the num­ber of seal­ing con­tours. The high­er this coef­fi­cient, the bet­ter the heat and noise insu­lat­ing prop­er­ties of the win­dow. The mod­els of the Kale­va com­pa­ny have K = 0.71 — 0.92, the win­dows of the Ger­man man­u­fac­tur­er — K = 0.62 — 1.05. That is, the Rehau com­pa­ny has a wider range of KST.

To sum­ma­rize: win­dow sys­tems of com­pared man­u­fac­tur­ers have approx­i­mate­ly equal oper­a­tional prop­er­ties, and you can choose com­plete­ly iden­ti­cal mod­els from one and the oth­er com­pa­ny. How­ev­er, Rehau pro­duces some win­dow sys­tems with a wider range of per­for­mance char­ac­ter­is­tics, there­fore it offers a wider range of prod­ucts.