New Member heat loss check and design help

Hello this is my first post!!! Need Help to set up my radiant heat. First part is to verify the load data below. To make sure I am in the right ball park as this is my first time doing this. Below I will go over building build as to help clear up any questions before hand. Only thing that is done is the install of the pex pipe in the concrete and a small forced hot air unit to make the area warm over the past few winters. I work save money and build then do it all over again.

Building plans and permits are required here in my area. I am a DIY person within reason. I have friends that work in the trades and I help them they help me.

I live in the Kingston New York 12401 area of upstate New York. I have been working on a shop build since 2015. In 2015 I poured the 28W x 48L (1344sq ft) monolithic slab with a 2 foot by 2 foot outside edge with 5 inch the middle of the floor. Floor is about 45 yards of concert with fiber mesh. The base was 4 inches crushed stone compacted and watered a few times to make it strong. There is a vapor barrier and 2 inch xps foam under all concrete. There is a 1 foot by 1 foot square ½ inch rebar grid over the floor on 2 inch heavy metal chairs.

The 2 foot thicken edge of the concrete floor and the walls on top are insulated concrete forums with an 8 inch of concrete about 12 ¼ inchs wide. The pex pipe was started about 30 inchs in from the edge of the concrete. Pex pipe lay out is 23W x 44L (1012sq ft). Pipe was zip tied to the rebar is 4 zones of uponor pexa ½ inch heating pipe about 260-280 feet each. Wish I had just put in 5 loops but can’t change that now LOL… The outside of the slab is insulated by 3 - 6 inches of xps foam, with a horizontal piece going out 16 inches on the bottom.

The walls are ICF with 8 core 12 feet high. Openings for the walls are follows.
1. Man Doors 2 each 36 x 80 in solid wood door with double pain glass in the very top only.
2. Over head door 10’ x 10’ with a r18 rating
3. Windows are Anderson 400 series 32” x 46”

The upstairs of the building is a big gambrel roof all in one room at this time. It is 13 feet and change in the center. This is made out of 2x12 x12 on all four side of the gambrel. Roof when it is insulated will be at lest an r38 and the walls an r 21.There will be a double solid wood door out front and 6 Windows that are Anderson 400 series 32” x 46”

Currently I have a 60,000 BTU force hot air unit 96% that I use to heat the ground floor area when I am working out there and leave it about 50-55 when not working.

I have done a heat loss but not sure it has been done right. See info below.
The zone load for the ground floor is around 23,600 with a flow of 2.37 GPM of 120 water and a total of 5.4 head. The outside temp was used for Kingston NY with a 2 degree temp. The room temp was set at 70 with floor
temp at 79.
The zone load for the second floor was around 22,600 with a flow of 2.26 GPM of 120 water and a total of 3.9 head. The outside temp was used for Kingston NY with a 2 degree temp. The room temp was set at 70
with floor temp at 79.
Total heat load was 41,550 ( second floor numbers may have a gain from the down stairs as the numbers
don’t match.) Total head was 6.1.

This year I took an old 15,000 btu window AC unit put in a window and it would cool down the shop on the very hot days here in NY. I am talking about 96 outside and the room could be 76 inside. This was only used a few hours a day. I would work outside till the heat got too much then work inside for a few hours in the middle of the day.

The primary heat for the building will be radiant but will keep the force hot air for any needed increases as the slab is too big to change in a few hours time.

Can someone please double check to make sure the numbers are in the right ball park for heat loss load info?
Once the loads are verified or fixed I will be working with lots of help from you all for the right equipment and way to have it installed.

I would like to use equipment that once installed would be like my oil boiler that I can service on my own. Pellet stove for heat and oil for hot water and back up heat source. Burn less than 400 gallons of oil a year and have all service parts on hand for any break down. Boiler service man comes by every 2 year for a cleaning and check up. I do the service the other years to include pump strainer, filter and a nozzle.

I am not a heating or plumber so please help me out and teach me please!! I have spent over 500 hours reading on the right and best way to do this. Then you think you on the right path and you read something and you’re not sure. This is one of my ideas. Install a GV90+4 84,000 BTU High Efficiency Boiler (Propane) a friend has one heating his shop with radiant heat that is working good. I would use like to use 40 gallon indirect water heater for the heated floor. This way I could set the floor temp to the 120 and be done with it if I need more temp would be easy to turn up to 130 or down to 110.

Once the heat loss is verified I will move to design phase. Once the design is done I will go to 5 or 6 plumber in the area ask for the cost to install this design.

Sorry for this long book LOL I hate to write. I did not want to leave anything out !!

Can someone check the heat loss and then help with the best was to make this work.

Thanks
Jason