I last posted about a year ago complaning of irritants in my home that appeared to be coming from my horizontal loop that contained methyl alcohol.My combustible gas detector went off around the pump flanges and canister in the basement. Anyway, a month ago I had the system flushed of the MA and filled with food grade propylene glycol , not only to ease my mind but to also satisfy a requirement by the state to receive a rebate. A few days ago I noticed the geo running longer than usual to meet demand so this morning I took some readings. My EWT was about 39.5 which is good, but my discharge air coming out of register was 77 during 1st stage and when 2nd stage kicked in the max discharge temp was 85. The system then ran for 1 hour 12 minutes to meet demand and it's only 20 degrees outside. When alcohol was in system 1st stage was 84 degrees and 2nd ran about 93/94 discharge air. Can the glycol be that much less efficient or could there be another problem?
P.S. the irritants in the home have disappeared since installing glycol.