Radiant heat has been used in cementitious slabs since the times of the Romans providing amazing, comfortable heat. However, many building design considerations have changed … so too with radiant slab heating. It has become increasingly evident that an over-slab assembly like InsulHeat makes more sense in modern buildings than in slab radiant heat. Why?
Far faster response. Higher efficiency. Cut slab installation costs. No under and edge insulation costs. No curing. No cracks. Flooring Goods Friendly. Save time and money.
Slower response. Slow efficiency. Expensive slab installation. Under and edge insulation costs. Requires curing time. Prone to cracks. Messy installation process. Labor intensive and time consuming.
Problems with radiant concrete slabs center around poor response time, heat loss and lower total efficiency, construction challenges and structural issues in seismic design areas. In slab radiant has PERT tubing in the middle of the slab meaning that the whole slab needs to come up to temperature before heat is radiated to the room for the floor surface.
It takes a long time from start up for heat to penetrate a large slab and start radiating to the surface at a useable temperature. This results in the well-known issue of poor system response time in both heating up and cooling down, if solar gain occurs. These problems can be mitigated somewhat by outdoor reset controls, but imperfectly. InsulHeat addresses these issues directly.
Many tests have been conducted over the years regarding slab insulation. The issue of downward heat loss and the thermally destructive introduction of water below the slab is well known. What has not had as much attention is the far greater problem of lateral edge slab heat loss, which is actually a larger problem. Both applications of insulation are required (below and edge), or you are throwing money away in bunches over the life of the building.
A radiantly heated 4” slab absorbs a large amount of energy to heat the slab before it reaches a sufficient temperature to re-radiate to the room. This takes time and energy. Often 4x-10x times longer than an InsulHeat system. Radiant slab systems respond very slowly to rapid heat gain conditions (i.e. late afternoon western sun) often resulting in over-heated rooms.
Avoiding current or future incursions of water under a slab is not a certain construction bet. If moisture enters under a radiant slab the system heat loss increases significantly. Water is a great conductor. InsulHeat can be installed with moisture or water proofing adhesives.
Compounding the issue of edge slab foam insulation is that it must be protected from the elements and incursion of termites into the home, a significant problem in many regions in North America.
Seismic issues: Along the Western United States many engineers no long permit radiant PERT tubing in their structural slabs due to seismic code design requirements. Post tension slabs cannot have penetrations thus a glued/insulated topping panel makes the most sense.
Is conventional Radiant In-Slab Heating Actually Cheaper to Install? Yes, but by just a little if done right…
If you create an energy efficient radiant in slab heating system, the costs are very similar to an InsulHeat solution. Why?
• Pouring a structural slab without radiant tubing inside is much faster. No blocks. Not tying off tubing. No Insulation.
• Pouring a slab without field application of under slab or edge slab insulation is far less expensive
InsulHeat Overslab in new construction. InsulHeat in retrofits over an existing slab.
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InsulHeat is the best option for insulated radiant panels in the business. Our high quality panels are constructed with tough EPS foam and a highly conductive aluminum laminate. Your best choice for insulated radiant heat.