In floor heating vs. radiant vs. forced air in shop??

[jgrreed]

Just curious...why should a plumber not want you to put PEX in the slab????????

Pat

Dunno why, he seems adverse to the in-floor for some reason. Says it'll end up costing me more that just a radiant heater. Have a lot of respect for what he has to say, but I disagree with him on this one. SO MANY people say they love there in floor, and I'd tend to agree. Even if it costs me a bit more, I'm doin' it!! I spent the last 2 years living in a fairly fancy walkout style house built on the side on a mountain, WITH NO INFLOOR HEAT!!!.....it sucked. The fancy hardwood and tile are negated pretty quickly when your bare feet step on a floor that's hovering just above freezing!!!

Great ideas on tagging the PEX tubing to prevent inadvertent tube-drilling. The PEX shouldn't shift around during the pour if it's wired or zip-tied properly, yes/no???

-Jer.

 

[Egon]

Your ambient temperatures of the last few days will have no effect on your decision will they????

 

[patrick_g]

Great idea about the thermal imaging. I thought any tubing would tend to move during the pour so you can't really end up knowing exactly where it lies.

Our in-slab PEX for our hydronic heat was secured to the rebar with plastic wire ties so it wasn't going anywhere. Since the PEX is empty (not full of water, just air) it would float up to the top if it were not secured.

Pat

 

[Stampeder]

Having owned a house with radiant floor heating in the floor and a basement shop in Canada (where it is COLD in winter) I will HIGHLY recommend installing it in your shop. I now live in East Texas and have plans to build a 40 X 65 foot shop which will have radiant heating in it here. Yes Texas gets cold in winter.
My system in Canada used a hot water heater for both the in floor heating and domestic hot water. They had separate coils and both were heated by gas.
The cost is a little higher to get it up to temperature but well worth it.
As to having a plumber do it, that's a crock. Mine was done as part of the construction but it is well within the skill of most of the contributors on this site. There is lots of information on the web about how to do it. PEX is the only thing to use. By the way buy extra PEX. It's good to 300 psi and makes an excellent air distribution system from you compressor around your shop. It's dirt simple to work with and doesn't suffer from condensation in the lines. It also has the added benefit of being easy to reuse.
As to where the pipes are, well I took digital photographs before they poured my basement floor so I could locate the pipes before drilling any holes. I did the same thing for the whole house before the put up the drywall. It was a real life saver when I came to installing cupboards and all sorts of other things.
As to the benefits of working on a floor with radiant floor heating, my calves always used to get cold and my feet and legs would ache after a while. Working during the winter with the floor heat turned on was a REAL pleasure. I could stand for hours without feeling cold, tired or fatigued.
Oh by the way fixing a leak is no big deal nor is it expensive. Our neighbour in Canada had someone drill through one of their floor pipes and it was about an hour all told to fix it. Chip up the concrete, it's only an inch down to the pipe, cut the plastic tubes with a tubing cutter, add in the splice (it crimps into the pipe), cover it up with top coat. You can do this yourself as well.
I bought my own crimping tool because as I said above I use PEX in other applications and seem to be continually doing modifications for new projects.
My recommendation is go for it. You won't be sorry. I just wished our current house had it in it.

Good luck with it.

If you are interested I still have pictures of the floor before the concrete went down I could post.

G.

 

[gordyy]

as both an installer and a user in floor is the way to go all the way
however having said that as one living in ND where we were -20 three days ago and we are at 36 and rising today, have not only the floor heat but some kind of quick heat to bring up the temp when needed. floor heat does not have a real quick and fast response time with the sun and all we end up using our other heat source a lot during the spring and fall, as if you have the floor hot it can get too hot and if you turn it down it does not respond fast enough as you would like on a cold morning
also as fas thermostat and controls do not get to cheap. get thermostats that sense both air temp and slab temp or your control is not good enough to keep a constant temp

 

[patrick_g]

Gordy, I spent 3 consecutive winters in Minot and appreciate the weather situation. I am in south central Oklahoma and our weather is quite variable. We recently had days of frost followed by a couple days of 70's followed by a couple days in the 80's followed by more frost.

I have in-slab heat in part of my home. I have forced air (heating and cooling) to the zones with in-slab heat. When the outside temp is so danged variable the self defense move is to set the T'stat for the in-floor a few degrees cooler (2-3) overnight and then either manually or with a programmable T'stat set the air temp cooler overnight and to the desired temp in the morning. The floor is comfortably warm to your bare feet day or night and during the day the room temp is what you want with less over and undershoot of temps. There are other successful approaches but this works for us.

Without some sort of strategy as mentioned above to prevent it you will be overheated (sometimes a lot!) if the outside temp goes up much and cold if the outside temp goes down much.

My geothermal heat pump which services the in-floor and in-ceiling hydronics is "WaterFurnace" brand and can make either hot air or hot water or both at the same time. The other two heatpumps are air to air with propane furnace backup selected by outside thermostats.

Stampeder: Regarding in-slab shop heating...

In-slab heat is not practical regarding nightly or "off day" setback. It is not practical to heat a slab intermittently. You have to heat it all the time whether or not the space is occupied. If the shop is only occupied on an intermittent basis this makes the efficiency really low or stated another way; you are paying to heat it all the time and using it once in a while. If money is no object and you can afford to waste all that energy, consider saving the energy and sending a check to a worth charity. (PM me for the wire transfer # to get the $ to me)

Alternatively, heat the floor just a little so it is comfortable but not enough to supply all the heat required to fully heat the shop 24-7 and use a second source of heat (water based baseboard heat or radiant or wood or...) for when it is actually occupied.

PEX is OK for shop air. You want UV resistant PEX and should consider painting it for additional protection as it deteriorates with sunshine. (Never buy PEX from a supplier who stores it outside pending sales!)

My plumber is also a heat and air contractor, just not MY heat and air contractor. He has done lots of shop air installs and will do PEX on request but states flatly black iron is better. My installation uses a little PEX between the compressor and the air dryer and black iron thereafter.

Whatever you do USE NO PVC IN SHOP AIR INSTALLATIONS!!!!!

I find that I need rubber mats where I stand beside various machines such as drill press, lathe, table saw, band saw, jointer, sander, etc. This goes a long way to ameliorating the cold floor syndrome. Nice rubber mats insulate fairly well and cancel out some warm floor benefits. This is not a case of "sour grapes" because I elected to not use in-slab heat in my shops (24x36 and 21x52 with a common wall.

I just didn't want to waste at least 65-80% of the energy used to heat the shops. I sometimes spend at least 8-9 hours a day at least 5 days a week in at least one of the shops. This is a tad over 25% occupancy so is almost 75% waste of energy if I heated it all the time.

Pat

 

[Redneck in training]

Dunno why, he seems adverse to the in-floor for some reason. Says it'll end up costing me more that just a radiant heater. Have a lot of respect for what he has to say, but I disagree with him on this one. SO MANY people say they love there in floor, and I'd tend to agree. Even if it costs me a bit more, I'm doin' it!! I spent the last 2 years living in a fairly fancy walkout style house built on the side on a mountain, WITH NO INFLOOR HEAT!!!.....it sucked. The fancy hardwood and tile are negated pretty quickly when your bare feet step on a floor that's hovering just above freezing!!!

Great ideas on tagging the PEX tubing to prevent inadvertent tube-drilling. The PEX shouldn't shift around during the pour if it's wired or zip-tied properly, yes/no???

-Jer.

You can install it by yourself. I would staple the tubing to the insulation and then put the rebars on top. Placing the tubing lower will result in more even surface temperature and less vulnerability to screws drilled to the floor. The tubes are easy to find with infrared imaging camera but you need a friend in local fire squad. Otherwise you can use a $25 infrared thermometer. Press the trigger and pass it over the floor. The tube is right under the maximum temperature. It works best when the floor is turned on after being few days off.

Look here.
Geothermal Heat Pump - Pond Boss Forum

 

[ineroth22]

Hi..,


I think you are asking three questions. One is how efficient is heating vs. radiant and radiant vs forced air. That is discussed all over the place (not answered, but discussed)... right....

 

[1950T]

heated floor in a shop allways worried me because of the accident factor. you get hurt or cut bad. you passout. that floor is gonna keep the body warm enough to bleed out.

just my thoughts.

 

[wedge40]

heated floor in a shop allways worried me because of the accident factor. you get hurt or cut bad. you passout. that floor is gonna keep the body warm enough to bleed out.

just my thoughts.

:laughing: :laughing: :laughing: :laughing: