Insulation question

[John Donhowe]

It was 35 and very sunny here all day yesterday and I didn't go to the shop until about 3:00. The temperature in the shop was 64. The heater was not running and I know from previous times it does kick off at the set temperature.

What we have here, m'boy, is a phenomenon known as solar heating! Your shop is apparently really good at absorbing solar energy (both light and heat), and because of your insulation, losing less to the outside- congrats! The downside is that it could get really hot in the summer unless you have good ventilation.

[Jim Andrew]

Do you have south facing windows? South windows do gain heat in winter when the sun is low in the south. They don't hurt you in summer because the sun is directly overhead.

[William C Rogers]

It wasn't quite as sunny yesterday, however I didn't get to the shop until about 3:00 and it was 60 inside. Same effect. I haven't had a chance to put additional thermometers in yet. The shop has north, east, and west windows. Facing south there are two overhead doors one 16X10 and one 8X7. I guess I need to be happy, but still don't understand it. Snow on the roof top this morning. As soon as I get time I will get measurements in different areas. It does feel warm. The gas bill will be the biggest tale tell when I get that.

[Mike Heidrick]

It sure does look great!

[William C Rogers]

What we have here, m'boy, is a phenomenon known as solar heating! Your shop is apparently really good at absorbing solar energy (both light and heat), and because of your insulation, losing less to the outside- congrats! The downside is that it could get really hot in the summer unless you have good ventilation.

Well I can confirm that I am getting a solar heating effect. The only day Last week I did not see a rise was Monday, very over cast 18 degrees and windy. Tuesday it was also 18 degrees,but sunny and there was a 4 degree rise over set point. Yesterday I went out at 8:00 (21 outside) and the temperature was at set point and heat system running. It turned off shortly after and did not come on the rest of the day. 4:00 seems to be the peak 39 outside and 65 inside ( set point is 54 ). I checked the temperature above the drop ceiling and it was 7 degrees colder than the room temperature. This building is different as it only has gable vent and no roof ridge vent. My previous building only had a roof ridge vent. Other differences are I used great stuff to seal all of the correlated openings at the bottom and the wainscot. I also ran my outlets in conduit on the outside of the walls rather than have them in the walls. I remembered a lot of cold air entering around the outlets in my previous shop. Also this shop has a drop ceiling. I still have a few areas to seal and caulk, buy Hopefully all this will reflect in my energy bill.
Edit: I am not just relying on the thermostat reading. I have a liquid thermometer and I am using a thermocouple with my meter. All are within a couple of degrees of each other.

[Jim Andrew]

I think you will find that drop ceiling to be a real help in heating AND cooling. Metal buildings build up much heat in summer, and having the ceiling as another barrier to the summer heat will be great. You may even want to add some kind of a power vent to the attic for the summer months.