I have no intention to ever be more than a hobbyist and DIYer so I have cheap equipment. The thermocouple readers were around $19 each and the manifold set was around $50. I am taking lots of data points in the hopes that error will average out.
I managed to get in two tests today and each one made improvements. First I recovered the propane and vacuumed the system. Then recharged and weighed the cyclinder before and after. I put in 4.25 oz which I was expecting to be overcharged. These are the results.
Then I disconnected the 85 watt puller fan and cobbled up a 15 watt pusher as shown in photo. No change in the charge.
And here are those results.
That is a really wimpy fan but it sure works good as a dehumidifier and it's using less kWh for heating. I believe there is a small leak so I can repeat this test every day or two and see how it performs with smaller charges.