A theoretical and experimental study is made for underfloor heating system using solar collectors. Also a study for a similar system using solar ponds is made under the same local conditions. Results obtained show that the solar collector system is 7% more efficient than the solar pond system. Economic analysis show that the Solar Collector System (SCS) will break even earlier than the Solar Pond System (SPS). Practical considerations show that the SCS requires less operation and maintenance work. (C) 2003 Elsevier Ltd. All rights reserved.