A hydronic heater is a baseboard, portable or under-floor system that uses a hot liquid — such as water, a special antifreeze or oil — in copper tubing to deliver heat, rather than the typical electric baseboard heater element. The copper tube contains an electrical element surrounded by the heat transferring liquid. A hydronic heater operates at about 200 degrees F, which — unlike standard AC baseboard heaters — is too low to burn dust and create IAQ issues.
