Question about radiant heat and $$$

[CMcAllister]

Hello all. We will soon be getting started on our new shop building. This will be a pole building, 40'x52'x12', well insulated and located in the Mid Atlantic region.

We would like to put radiant heat in the floor, if the budget allows, and I have some elementary questions that I have had trouble getting answers to. How much should we expect to have to spend to have the heat system installed by a professional? If I were to do some of the work myself, steel and tubing installation, etc., how much would we be able to reduce the cost?

We will be installing A/C also and have to factor that in when making decisions on the HVAC

 

[jsmith6752]

your biggest cost will be the 2 inch foam (blueboard etc) I just bought it for $30 a sheet. It's not that big of a deal to do it yourself if you have the time

 

[BadgerBoilerMN]

Every HVAC system and particularly a radiant floor heating systems starts with a heat load analysis.

http://www.badgerboilerservice.com/images/SampleHeatLoadAnalysis.pdf

The biggest cost is in the proper design and installation of the boiler and control system. The insulation should be specified by a professional and the cost about 1 dollar US/foot. Our concrete contractor usually installs the rigid XPS.

You will need a heating and cooling load, then tube size, length and pattern should be on a CAD drawing. The radiant floor heating boiler may be electric, natural gas, propane, oil, wood or pellet.

 

[aandpdan]

Another thing to consider, how often you use it. Radiant heat is great but it can be slow to respond, we're talking hours, not minutes. If you use your shop all the time it can't be beat.

If you want fast response, especially as you are considering A/C, maybe consider hot air.

And always, start with a heat loss calculation.

 

[stingry]

Keep in mind that this is just a rough estimate based on a radiant floor I put in my 3600 sq ft shop. $2000 for 2" EPS insulation, $3000 for a heat source, valving, controls. PEX tubing, etc, for a total of approx. $5000. As for labor to design and install, I have no idea. If you use the old rule of thumb, 1/2 labor, 1/2 material, you could have upwards of $8-10,000 in a turn key installation! Personally, I would put in a conventional high efficiency furnace or heat pump since you will be installing AC. Seems counterproductive to put in a floor radiant system and then put in an AC system with all the venting, etc.


Cheers
Steve

 

[CMcAllister]

Appreciate the responses. Radiant heat would be great, but I definitely also need A/C. Can't do the fabrication/welding, in 95 degrees and 85% humidity, all day anymore. We have a pretty tight budget and also have equipment and other things to spend money on. Seems like the decision is being made for me.

 

[trythis]

Overhead radiant tube heaters provide similar comfort for a lot less money and toast up the place much faster than in floor radiant. Looks like you will have ceilings that will accommodate a radiant tube heating system.
No blowing air, everything in the shop is heated, not the air. Quick recover times, and leaving it on 50 Deg on your days off to save money is a benefit over slab radiant.

 

[BadgerBoilerMN]

Recovery has to be defined. Since cooling is enhanced by air movement and heating in not, they should be two separate systems, yes it costs more.

If you will always heat the shop and work 5 days a week therein radiant floor are for you. Nothing "recovers" fast than a radiant slab. When the door is opened and all the conditioned air is lost, the slab is still warm.

Infrared is good for comfort but will cost up to 20% more to operate. It works on the same radiant principles as radiant floors but the combustion efficiency will be dramatically lower (infrared run hotter stack temperatures than condensing boilers) and will increase heat loads as the convected heat from the tubes will make for a hot ceiling.

Forced air is for trailer homes. I would install (have installed) and mini-split in my shop since heating hours here in Minnesota are 6 times greater than cooling hours.

Since you will be insulating the floor, it makes sense to install barrier PEX for future use as suggested, and a conventional air to air heat pump furnace with propane backup if you must.

This is the most cost effective (ROI) solution in the short term. Ventilation and makeup air are other factors and even more reason to get some professional help before spending money on HVAC equipment. This is not the place really.

 

[BADSIX]

i would think a forced air heat pump would be the allaround way to go.

 

[larry_g]

I'm a believer in floor heat. I find that with radiant heat from below the tools, machines, and my feet are warm. The ambient air is cool so your not sweating doing physical work in the shop. As you mentioned you will be doing fab work and probably handling lots of steel and working on steel tables. With radient heat this steel will be warm to the touch. If you have other heat that you use to bring the building up to temp in the morning all this steel is going to be cold to the touch. With radiant heat you can also be comfortable with the building 10-15 cooler. Just my experience in working in different shops.

lg
no neat sig line