Custom Aluminum Windows: MB-79N, MB-86, MB-104 Passive or MaxLight?

Most people who ask us about aluminum windows have already decided on aluminum. What they want to know is which system to pick. Our aluminum windows page lists four systems, and on paper they look similar. In practice each one fits a different kind of project, so here is how we explain the choice.

What all four have in common

Before the differences, the shared baseline. All four are thermally broken aluminum systems built for tilt and turn and fixed units, and all of them are tested to the same structural level:

• Class AW, PG60 at 60 x 99 in.

• Design pressure of +/-60.15 psf.

• Air infiltration under 0.02 cfm/ft2.

• Forced entry resistance to ASTM F588, grade 10.

• Lead time of 6 to 8 weeks by air or 8 to 12 weeks by ocean freight.

So the decision usually comes down to three things: insulation, frame depth and the size of the openings.

MB-79N: the all-rounder

The MB-79N is the most versatile of the four. The frame is 79 mm (about 3-1/8 in.) deep, U-values run from 0.25 to 0.39 depending on the glass, and acoustic glazing can take it up to STC 48.

Its strong point is size. A single unit can go up to 106 x 106 in., which is the largest of the four. It also has a renovation profile and a nailing flange option, which helps on typical U.S. framing and on replacement jobs.

Pick it for: mixed climates, large single sashes, renovations and projects where installers prefer a flange. We wrote more about the system in our Aluprof MB-79N article.

MB-86: more insulation, same look

The MB-86 has an 88 mm (about 3-29/64 in.) frame and much better thermal performance, with U-values from 0.16 to 0.35. STC is up to 48, like the MB-79N.

The trade-off is unit size. One unit tops out at 74 x 74 in., but assemblies can reach 137 x 102 in. If your design uses several mid-size sashes coupled together rather than one huge one, that limit rarely matters.

Pick it for: colder climates, modern homes with large glazed walls and anyone who wants better insulation without going to a passive-house frame.

MB-104 Passive: the energy pick

This is the deepest and best-insulated frame we offer in aluminum: 104 mm (about 4-3/32 in.), with U-values from 0.14 to 0.21. It also has the best sound rating of the group, up to STC 52, and accepts glass up to about 3-3/16 in. thick.

Single units are limited to 74 x 74 in., but assemblies go up to 165 x 102 in.

Pick it for: passive house and net-zero projects, very cold regions and homes near airports or highways where both heat loss and noise are a concern.

MaxLight: slim sightlines

MaxLight is the design choice. The frame depth is 75 mm, the visible profile is very slim, and there are several versions, including Design, Invisible and Steel looks. U-values range from 0.15 to 0.37 and STC goes up to 45. A single unit can be up to 70 x 70 in., and it can be installed through the frame, with straps or with a nailing flange. More on the MaxLight page.

Pick it for: contemporary architecture where you want as much glass and as little frame as possible.

Quick comparison

• MB-79N: U 0.25 to 0.39, STC up to 48, single unit up to 106 x 106 in.

• MB-86: U 0.16 to 0.35, STC up to 48, single unit up to 74 x 74 in.

• MB-104 Passive: U 0.14 to 0.21, STC up to 52, single unit up to 74 x 74 in.

• MaxLight: U 0.15 to 0.37, STC up to 45, single unit up to 70 x 70 in.

Lower U-values mean less heat loss. If you want to understand the numbers better, see our pages on U-factor and STC ratings.

Colors and finish

The most popular choice is black inside and out, which suits almost any modern facade. Other colors are available on request, so tell us what you have in mind when you ask for a quote.

Aluminum or something else?

Aluminum makes the most sense for big openings, slim frames and modern design. If budget is the main driver, our uPVC windows reach similar U-values and usually cost less, and wood windows are the choice for traditional homes.

Get a quote for your aluminum windows

Send us your sizes or drawings and we will price the project in the system that fits it best, usually within 48 hours. You can see the full specifications on our aluminum windows page or go straight to the contact form.