1. In the first case, the aluminum fins do a good job of transferring more of the available energy from the hot water out of the pipe. In particular, aluminum fins place thermal energy directly on the underside of the floor to be heated, whereas ducts without aluminum fins primarily heat the air in the cavity and then transfer the air to the subfloor through inefficient mechanisms of warm air convection and conduction . In the case of 5/8tubing, a heat output of 15,124 btu/HR was observed at elevated temperature, while the heat output for 1/2tubing was only 10,955, or a 38% increase. However, at lower temperatures (118F vs. 145F), the improvement was less pronounced, and the improvement dropped to about 11 percent. It’s important to note that the comparisons aren’t quite the same because the 5/8tubing is slightly larger than the 1/2tubing, but other studies comparing tubing only show that the positive results are mostly attributable to aluminum.
2. Another very important factor in the design of radiant heat is to control the so-called “تعويض الخساره”, ie the heat energy in the wrong direction. Those who would say that heat loss downwards are irrelevant because heat always rises are misguided. The joisted floor application does control heat losses to convection and conduction to near zero in a natural and efficient manner. However, radiant heat can travel in all directions.
Practical experience and these data strongly suggest that if the radiative heat loss in the downward direction is not well controlled, the results will be unsatisfactory. When heat is lost down to another heated space, that heated space may actually be overheated and the intended space is not sufficiently heated. These data strongly suggest that most of the thermal energy provided by the 1/2″ PEX tube without aluminum fins is going in the wrong direction. This situation must be corrected by adding some kind of extra insulation expense. Unfortunately, this This remedy usually does not occur.

An underappreciated advantage of aluminum thermal pads is its low emissivity (nearly zero). This means that when aluminum is heated, it does not emit radiant energy like other materials. In the present case, this characteristic is well used to control the radiation “تعويض الخساره” أيّ, if left unchecked, can seriously damage the system. The superior effect of the low emissivity is clearly demonstrated by the thermal image, which shows that there is almost no downward radiant heat loss when aluminum is used.
Aluminum thermally conductive plates
In particular, the thermograms (below and left) are instructive. Infrared cameras simplyseethe radiative heating spectrum, which is then mathematically corrected to predict molecular temperatures from the measured radiation. This method works for almost all materials except aluminum. It can be seen that the aluminum thermal fins are blue in the temperature record, and the falsely reported temperature is only 67 degrees, when in fact it is 106 degrees. It is worth noting that the actual infrared energy emitted by aluminum is almost zero. The camera is recording reflected radiation from the environment below. تقلل هذه التأثيرات من فقد الألمنيوم للإشعاع إلى ما يقرب من الصفر.

3. خاصية أخرى مفيدة للألمنيوم هي أنه يعكس الطاقة المشعة التي تضربه من مصدر آخر. ستعكس طبقة إضافية من رقائق الألومنيوم الموضوعة تحت الأرضية المشعة أي طاقة مشعة موجهة بشكل خاطئ. لحسن الحظ, يمكن تحقيق هذه الخاصية برقائق ألومنيوم رفيعة للغاية, والتي غالبًا ما يتم ربطها بورق التسليح من أجل القوة. أظهر هذا العمل في وقت مبكر على قيمة الحواجز العاكسة احباط. الطاقة المشعة التي يمكن تضليلها بخلاف ذلك حيث تنعكس خسارة العودة صعودًا إلى الطابق السفلي, حيث تكون مفيدة لشاغليها. تُظهر الصورة الحرارية بالأشعة تحت الحمراء بوضوح تحسن المواد المدعمة بالرقائق مقارنة بالورق العادي.