The magnetocaloric effects (MCE's) due to the itinerant-electron metamagnetic (IEM) transition have been investigated for La(Fe xSi1-x)13Hy compounds. By controlling the hydrogen concentration y, the Curie temperature TC was elevated from around 180 K to room temperature with retaining the IEM transition. A large magnetic entropy change ΔSm was confirmed in x = 0.88 even in relatively small magnetic field and ΔSm is enhanced by increasing Fe concentration up to x = 0.90, consistent with the theoretical predictions. The value of ΔSm is still large enough after increasing TC by hydrogen absorption into La(FexSi 1-x)13Hy compounds. In these compounds and hydrides, the value of the adiabatic temperature change ΔTad estimated from the specific heat data was also confirmed to be large. Furthermore, directly measured adiabatic temperature change ΔT add almost accords with ΔTad, both in magnitude and thermal variation. In addition, La(FexSi 1-x)13Hy, compounds have excellent thermal transport properties. Consequently, the present compounds are one of the promising candidates for magnetic refrigerants working at wide temperature ranges covering room temperature.