A typical heat pump installation viewed. The actual outdoor unit is installed outside the home and needs to have certain clearances to allow proper servicing of the equipment as well as making sure the location does not increase the noise level. This Lennox XP17 series heat pump is not only the quitetest in the industry, it is also the most efficient single stage heat pump you can buy. All tests are done by 3rd party agencies and certify the sound levels and effieciencies. You will be comfortable and save energy 24/7, 365 days a year. The Lennox Signature models are also solar ready, an industry exclusive.