Go to the OpenStack Documentation for the latest version of the Installation Guide for Red Hat Enterprise Linux, CentOS and Fedora which includes a chapter on installing the Orchestration module (Heat).
There are instructions for installing the RDO OpenStack distribution on Fedora and CentOS.
If installing with packstack, you can install heat by specifying --os-heat-install=y in your packstack invocation, or setting CONFIG_HEAT_INSTALL=y in your answers file.
If installing with RDO-Manager Heat will be installed by default.