ðɪs ɪŋkɹˈiːsᵻz ðɪ ɪfˈɪʃənsi ˈɛnɚdʒi dᵻlˈɪvɚd ˌɪntʊ ðə bˈɪldɪŋ vˌiːˈɛs. hˈiːɾɪŋ vˈæljuː ʌv ɡˈæs pˈɜːtʃɪst tʊ ˌoʊvɚ nˈaɪnti pɚsˈɛnt.
This increases the efficiency (energy delivered into the building vs. heating value of gas purchased) to over 90%.