Thermal and energy-saving terms in plain language — search
Heat loss
Energy escaping through walls, windows, roof, floor, ventilation. Measured in W or kWh/yr — the base figure for insulation.
R-value / thermal resistance
Material's resistance to heat flow: the higher the R (m²·K/W), the better the insulation. A wall at R=3 loses 3× less heat than R=1.
Heat pump COP
Efficiency coefficient: COP 3.5 = 1 kWh of electricity gives 3.5 kWh of heat. Drops in frost — check SCOP for the season.
Delta-T
Difference between heating supply and return temperatures. Small ΔT = inefficient system; optimal for radiators is 15–20°C.
Heat recovery
Returning exhaust-air heat to supply air — 70–90% of ventilation heat stays home.
Dew point
Temperature where moisture condenses. Insulation shifts the dew point inside the wall — wrong internal insulation = mold.
Thermal bridge
Area with worse insulation (balcony slab, reinforcement belt, corners) — point heat loss and condensation spot.
Passive house
Standard with heating demand ≤15 kWh/m²·yr — super insulation + airtightness + heat recovery. 10× less than a typical home.
Two-zone tariff
Different electricity price day and night (23:00–7:00 usually −50%). Requires a special meter.
Energy class
Building energy efficiency rating A–G by kWh/m²·yr consumption. In Ukraine issued after an energy audit.