ASHP are claimed to become healthier than fossil-fuelled heating for instance gasoline heaters by sustaining a more even temperature and preventing destructive fumes chance. An air-to air system is usually built to transfer heat in either way, to heat the inside of a constructing in Winter season and cool it https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/