HVAC and Radiant Flooring

[that-guy]

so i am looking to break ground over the Spring for my 30x50x14 steel shop. I want to put in radiant flooring before the concrete is poured (obviously). I am ordering the steel building to be insulated during construction, but i'm not sure what sort of HVAC system to install after the building is done. I know the radiant floor will keep the concrete at a nice temperature, but how much of that heat dissipates into the air to keep the overall temp manageable? at the very least i do intend of putting in an A/C system as summers in VA do often get into the 90's, but the winters, like now, are often in the 30's or sometimes less, so comfort is key

 

[fitter30]

There is no better heat than floor radiate. Even temp and quite. Read other posts for the proper insulation for the floor before you pour the pad.

 

[svtride]

Radiant floor, great way to heat a 1500FT^^2 shop. I live in SE MI. I started with Hydronic only via natural gas. Quiet, dustless, relatively cost effective for the performance 2-3$/day. Fast reheat of space after opening main door to bringing something in. I keep it at 58. Very comfortable to work in.

I added forced electric a couple years later as I installed Solar Panels and needed to use up my excess power which my utility banks for me. Louder but it offset my gas costs.

 

[yeldogt]

so i am looking to break ground over the Spring for my 30x50x14 steel shop. I want to put in radiant flooring before the concrete is poured (obviously). I am ordering the steel building to be insulated during construction, but i'm not sure what sort of HVAC system to install after the building is done. I know the radiant floor will keep the concrete at a nice temperature, but how much of that heat dissipates into the air to keep the overall temp manageable? at the very least i do intend of putting in an A/C system as summers in VA do often get into the 90's, but the winters, like now, are often in the 30's or sometimes less, so comfort is key

The floor will have no problems heating the space .... it's just a question of how you heat the water.

AC can be many things ... packaged unit -- split -- mini. What's your electric rate?

I would get a heat pump if doing AC -- there are times when you may not have the floor on and you need a little heat .... this happens in early fall and late spring.

Also -- think about how you are going to use the space. Planning the tubing is important. Most don't give it any thought -- the tubing is brining in the heat to the slab .... where that all come out will be hotter + the boiler with be there.

Sometimes splitting the manifolds works depending on overall temps. Some people have a space where they work ... or even a bench where they sit. Double up a zone of tubing in that area and you have created a warmer space where you are working. I always do this in a slab .... most larger spaces are not used the same throughout. My larger studio also has space for a couple of rarely used cars .. I restrict flow to that manifold and that end of the building is cooler. I have an extra loop under my main work/ desk area -- I flip that loop when I'm out there for the weekend. Since I'm not moving in that area,.. the extra heat is nice.

Tubing placement and spacing determines output above ....

 

[PWC Repair]

My climate here in Northern Arkansas is VERY similar to yours. My shop is 30x48x12 open span steel truss frame.....17.5ft tall in the middle. I insulated with 3" foam board and left an air gap between the foam and metal sheeting. I can keep my shop closed up on those 90+ degree days until noon or 1pm before it gets to 80* inside. Then I can open the overheads and the rest of the day it will still remain about 10* cooler inside. In the air gap between the metal and foam I have measured 130*. In the winter, I've noticed the air gap still works in my favor. The gap seems to be helping to trap the radiant heat and I have been gaining 3-4* on a cold but sunny day. Anyway I vouch for at least 3" foam insulation. I'm confident with the summer I've already experienced that a 3 ton dual head minisplit would AC my whole shop to a lower humidity 78* range. You can also rig up a fan coil for forced hot air when you don't want to run the floor. I made one up and that's all I've been using with an electric 50 gallon water heater. Keeping my shop at 46* at night and 58* when I'm out there. Watching te meter closely looks to be costing me an average of 2$ a day.