Hello Guys! It has been a while since I have been on here. The house, 4100 sq feet north of Houston, TX is working great. We have been in it three years now and all is well. I have just put up a barn and had a deep spring fed pond built. The barn is 2000 sq feet sheet metal, 16 foot walls, 3/12 pitch. It has (2) 12x14 doors and (1) 12x12 door and 2 man doors. The building will be spray foamed and more than likely have a large 14 ft ceiling fan in it. I have a manual J heat load calculation, but it is a little misleading. I am attaching it to this post. It calls for 2.27 tons of HVAC, but I do not think that this will work as I want to use it. The goal of this project is to keep the building around 85 during the summer and control humidity somewhat when the building is not being used. It is basically a shop for me... When I want to use the building, I want to be able to cool it down rapidly to about 70-74 and maintain that temperature while using the space. That being said, I am leaning towards a 4 or 5 ton unit with pond loops. I do have a professional pond loop installer that has been doing this for over 30 years. He will put whatever I want in the pond and the pond is 20-30 ft deep and about 1.3 to 1.5 acres in surface area. I still need to measure the new pond for accurate area. What are your thoughts. Doc? Anyone...? Has anyone done this type of installation before? Pics below with manual J attached.