Radiant floor question - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Garage - Tools
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-24-2011, 10:02 AM
Registered User
 
Last wiki edit: Wheelbase database Last photo:
Join Date: Jan 2007
Location: Virginia
Posts: 3,618
Wiki Edits: 1

Thanks: 6
Thanked 163 Times in 150 Posts
Radiant floor question

I'm getting ready to install the foundation and slab for my new shop, approx 50 ft by 60 ft. I was planning on putting PEX for radiant heat in the slab, but I'm having second thoughts for two reasons and I'd appreciate comments from those with experience. I'm located in the Washington DC area, so it gets below freezing for about two months over the winter.

First, I plan to install A/C as well - summer in DC is a swamp. Since I have to run ducts and an air handler anyway, would it be better to just use forced-air heat, possibly with a large outdoor wood-burning furnace?

Second, every radiant floor design guide I read cautions about furniture blocking the heat from the slab. Since my shop will have a number of cars parked in it, in addition to equipment in a machine shop and several pallet racks for storage, will the heat from the slab be blocked anyway?

Of course, I'm also worried about puncturing the tubing when installing things like a lift...

Thanks for your inputs.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-24-2011, 10:35 AM
37ford4dr's Avatar
bobs77vet
 

Last journal entry: frame repair
Last photo:
Join Date: Nov 2005
Location: Arlington Va
Age: 57
Posts: 738
Wiki Edits: 0

Thanks: 0
Thanked 16 Times in 15 Posts
joe how are you doing? i live in Arlington and two yrs ago built a 24x23 garage with Pex tubing in the floor for the radiant heat.....i have never hooked it up. my garage is 2x6 construction with 14' cielings roof trusses and well insulated . 3 windows, side door and large 18x8 garage door. the reason i never hooked up the pex was that i had an electric dayton 240v heater and for the time i use the garage weekends and nights i just turn the heat on and it warms it up to any temperature i want mostly 63-65*. it costs me about $1 a day to heat it. so with the high initial cost of the outlay for the radiant floor heating manifold etc i just cant bring my self to ante up the $$$ to pay for it. i had no problem laying the tubing and i knew before hand where the lift would go and at the same time i added more rebar to that area i moved the pex tubing away from it. i see no reason why you cant have more or less tubing in certain areas then others. for me while it would be nice to have i just dont see the cost justification for doing it at this point. running the tubing is the least expensive part of the project and is what i did so i have the abiltiy to add the heating source and manifold later if and when my current heating sources breaks.

there is no reason not to have a combination of two systems......forced hot air for overall shop and then the area where you have the machine shop or lift for working on cars have the radiant floor heating there.

you will want to insulate the under side of the slab so you have thermal break between the ground and what the slab you are heating.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-24-2011, 10:57 AM
OneMoreTime's Avatar
Hotrodders.com moderator
 
Last wiki edit: Health and safety in the shop or garage
Last journal entry: Yard Dog pic
Last photo:
Join Date: Jul 2004
Location: Washington State
Age: 70
Posts: 7,474
Wiki Edits: 3

Thanks: 66
Thanked 167 Times in 156 Posts
HVAC is one area that I am confident in..Given what you have described I would go with a roof mount system with the ducts in the ceiling as this is the most practical for a commercial type building..Of course you can use an updraft furnace to feed one of those systems if you cannot do a roof mount. When one does the heat loss one finds the A/C is the energy sucker and the heating load not so much..To keep heating/cooling costs down we cool to 75 in the summer and heat to about 55/60 in the winter..this seems to work out fine for a working shop..The wood burner may be a problem as I am not aware of any A/C units that use wood for the heat side.

Sam
__________________
I have tried most all of it and now do what is known to work..
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-24-2011, 11:01 AM
Registered User
 
Last wiki edit: General Motors transmissions Last photo:
Join Date: Mar 2006
Location: near Yellowstone park
Posts: 4,422
Wiki Edits: 27

Thanks: 13
Thanked 275 Times in 255 Posts
week end work ?

with radiant it takes a while to get the slab warm. IF you want it to stay warm all the time.they work good. . In the 4 car house garage we have a gas forced air system, just crank up the thermostat when I want to work. back down to 50 when just parking the cars inside.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-24-2011, 11:56 AM
ogre's Avatar
the 'Duracell Project'
 
Last photo:
Join Date: Nov 2009
Location: Motown
Posts: 1,502
Wiki Edits: 0

Thanks: 0
Thanked 142 Times in 121 Posts
joe
if your installing AC then i would stay with forced air heat.
no sense installing 2 systems. $$$ mega bucks $$$

frame it and insulate it like you would a house.
a pole barn is tricky to insulate well.

also think about partitioning your shop into heated and unheated sides.
my shop is 50x50, i have a 20x30 always heated work room,
a 17x30 heat as needed car bay and the rest is unheated.


all these doors go into a 20x50 unheated space.
there is a second door throgh the 16 ft door into the heat as need space.

Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-24-2011, 02:39 PM
Registered User
 
Last photo:
Join Date: Apr 2009
Location: Langley, BC
Age: 50
Posts: 83
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I'll reply to Q2 only as the economics are for you to decide.

Measure and figure out where your lift anchoring bolts would go and avoid running tubing there. If you can't or won't then if you wet the floor and turn the heat on you can determine where the tubing is fairly easily. A parked car will not block the heat, having insulation and vapour barrier under the slab will greatly "encourage" the heat to travel up to heat the room. In my opinion the heat from radiant is nicer, especially in a high ceiling garage as it heats the area where you are (the lowest 7 ft) and when you are creeping around on the floor if its a while before you get a hoist. Watch out for unintended naps under the vehicles

Have to agree with other posters, slab heating slow/gradual/continuous, not good for fast turn on, a timered/setback thermostat deals with that.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-24-2011, 04:38 PM
35terraplane's Avatar
Registered User
 
Last photo:
Join Date: Sep 2010
Location: MN, ON THE DARK SIDE OF THE MOON
Age: 70
Posts: 1,329
Wiki Edits: 0

Thanks: 2
Thanked 61 Times in 52 Posts
Floor heat

Quote:
Originally Posted by joe_padavano
I'm getting ready to install the foundation and slab for my new shop, approx 50 ft by 60 ft. I was planning on putting PEX for radiant heat in the slab, but I'm having second thoughts for two reasons and I'd appreciate comments from those with experience. I'm located in the Washington DC area, so it gets below freezing for about two months over the winter.

First, I plan to install A/C as well - summer in DC is a swamp. Since I have to run ducts and an air handler anyway, would it be better to just use forced-air heat, possibly with a large outdoor wood-burning furnace?

Second, every radiant floor design guide I read cautions about furniture blocking the heat from the slab. Since my shop will have a number of cars parked in it, in addition to equipment in a machine shop and several pallet racks for storage, will the heat from the slab be blocked anyway?

Of course, I'm also worried about puncturing the tubing when installing things like a lift...

Thanks for your inputs.
I have in floor heat in my shop and house, It is great and my shop costs less than the house.
Onemoretime said put it in the roof, bad idea, heat goes up, cold comes down, the higher up your heat, the higher the space is on the floor that's cold. With in floor heat your warm from toe to head.
The fluid in my lines are heated to 120 degrees so that goes through the lines the floor will be about 79*, it's all in what you set your stat to. I have two big fans, 3 blade that I have turning very slow pushing the air around .
My shop is 30' X 60', half has a 15' ceiling the other half has a 10' foot ceiling. When I built it They put a extra 1" of sand down, then 2" of foam Then the tubes 2 zones, then cement which they put a extra 1" of, so I have 5" instead of 4"
When it was down around zero I turned my heat down 20* from 70 to 50, the 1st week it was anywhere from -5 to -28 degrees, outside. The temp had only dropped 9* degrees in that week, after two weeks it had dropped 17* degrees, but the temp was a little above zero during the day and below at night.
I didn't put in central air I got the two biggest 110v a/c that I could get brand new about $275.00 each at the end of the season when they wanted to get rid of them. Central air would have been close to $2000.00, not counting duct work, I run both until cool, then shut one down, they are way up high and run by a hand held control, both on the high end of the shop.
I have only 3 windows and the service door plus big doors. This winter we have had a lot of snow, I watch by the big doors to see if the snow melts from leaking air it doesn't.
I have a lift but I don't have it bolted down as it has wheels and I can move it around. There is a upstairs, It is not heated but the heat goes up there and keeps it warm.
I live in MN so we get cold weather, the only thing I worry about is falling asleep on the creeper because it is nice and warm down there.

Bob

Oh you can run it with wood from outside or pellets, corn, gas, which ever way you want. You don't have the cost of duct, and you can break it into zones, so you only heat what you want.
Attached Thumbnails
Click image for larger version

Name:	shop 5.JPG
Views:	122
Size:	1.34 MB
ID:	52980   Click image for larger version

Name:	shop 9 9-20-06.JPG
Views:	99
Size:	1.08 MB
ID:	52981   Click image for larger version

Name:	shop lift 2.JPG
Views:	107
Size:	1.18 MB
ID:	52982  
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-24-2011, 04:45 PM
35terraplane's Avatar
Registered User
 
Last photo:
Join Date: Sep 2010
Location: MN, ON THE DARK SIDE OF THE MOON
Age: 70
Posts: 1,329
Wiki Edits: 0

Thanks: 2
Thanked 61 Times in 52 Posts
floor

More pictures. I do have a hanging heater for backup, it has never been on.

Bob
Attached Thumbnails
Click image for larger version

Name:	shop 7.JPG
Views:	94
Size:	1.26 MB
ID:	52983   Click image for larger version

Name:	shop 15.JPG
Views:	91
Size:	1.10 MB
ID:	52984   Click image for larger version

Name:	shop 1.JPG
Views:	84
Size:	1.88 MB
ID:	52985  

Last edited by 35terraplane; 02-24-2011 at 04:48 PM. Reason: add
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 02-24-2011, 05:16 PM
35terraplane's Avatar
Registered User
 
Last photo:
Join Date: Sep 2010
Location: MN, ON THE DARK SIDE OF THE MOON
Age: 70
Posts: 1,329
Wiki Edits: 0

Thanks: 2
Thanked 61 Times in 52 Posts
Radiant floor

Joe if you have any questions just let me know, If you want to get into more detail Pm me and I will give you my #

Bob
Attached Thumbnails
Click image for larger version

Name:	shop 2.JPG
Views:	84
Size:	1.79 MB
ID:	52986  
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 02-24-2011, 06:12 PM
Member
 

Last journal entry: JB's 37 Pickup
Last photo:
Join Date: Oct 2002
Location: Smoky Mountains
Age: 76
Posts: 2,358
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
I have the PEC tubing in the floor of my shop and would not trade it for any thing. Little further south than you, but in the mountains so don't think our winter temps are that far apart. I lived in Utah for 6 years with infloor heat and it was the best heating system I ever had. Two oversized 2 car garages with infloor heat and stayed at 50* all winter long. The primary heat source for the water was solar, with a tiny Paloma natural gas heater as a back up. The solar panels worked every day, regardless of the cloud or snow cover. Saw some temps down to -34F and the inside temp never varied more than 1/2 *. My shop has a 22' apex and it is chilly up there, but comfortable on the shop floor. The thermostat is set for 50* and holds well except if a roll up door is open for more than a few minutes. The thing about radiant heat, all of the vehicles, tool boxes, benches etc absorb the radiant heat and act like a reservoir of heat. They and furniture are a plus, not a negative. I use propane to heat the circilating water and have a 100 gal tank. This winter, I will use less than 350 gallons and the heat has been on since the first of Nov and will probably go off in mid to late March. This year, we will add hot water solar panels to the roof and the propane will become the back up.

As mentioned earlier, if you pour a 5 inch floor, then you will not have to worry about putting your lag bolts in if the PEC is installed 2" above the foam insulation and you don't try to drill your holes more than 2.5". Two inches is plenty for a 4 post lift, using epoxy to anchor them in. If you are going to install a 2 point, you might consider enlarging the foot print and adding more anchors. Do a search on my thread, Designing a New Work Shop and there are a lot of pictures and verbage on how it was constructed.

Trees

Last edited by trees; 02-24-2011 at 06:17 PM.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 02-24-2011, 06:19 PM
Registered User
 
Last wiki edit: Wheelbase database Last photo:
Join Date: Jan 2007
Location: Virginia
Posts: 3,618
Wiki Edits: 1

Thanks: 6
Thanked 163 Times in 150 Posts
I appreciate all the good comments, thanks. I suspect that I'll stay with the PEX. I do plan to have walls inside and heat zones, so the storage areas don't need to be as warm as the work areas. I also have a couple of roof-mount solar hot water panels and was planning on plumbing those as well - every little bit helps and they're already paid for.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 02-24-2011, 06:29 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,355
Wiki Edits: 0

Thanks: 223
Thanked 276 Times in 256 Posts
I have heard some horror stories from some of the HVAC guys here in Northeast Pa about the concrete not being so friendly to the pex tubing.
It doent like the expansion / contraction thing as well as the chemicals from the concrete while curing.If it springs a leak for whatever reason ,you cant fix it.
Honestly If it were me, I would put in radiant baseboard around the perimiter of the shop, use an outdoor boiler and an oil fired one for backup with a heat exchanger. There are outdoor woodstoves that can be multifueled, but I have checked into that for my remod, and they arent as efficient as putting in a dedicated unit.
With radiant it feels warm all the time and it is very even heat. Fanforced only feels warm when it is running, it stirs up a buttload of dust and its impossible to put the "unit" outdoors to contain the burner away from the air in the shop(VOC , solvents thinners etc. explosion...you get it)
I like the outdoor woodburner my neighbor has, itkeeps his house at 80 degrees inside all winter long.
I have an oil fired burner and my house is small and tight, I have used 275 gallons of oil so far this winter.
If oil keeps going up, I will be getting an outdoor stove and putting in a heat exchange for the hydronic (radiant baseboard) system in my house. If the fire goes down at night the oil fired boiler will pickup the slack.
Linn A
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 02-24-2011, 06:32 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,355
Wiki Edits: 0

Thanks: 223
Thanked 276 Times in 256 Posts
Also , instead of using zone valves , I used the TACO 007 series pumps with the integral check valve. They work great for zoning, and it is cheaper as you dont need the valve and a pump. just a pump.Pretty easy to wire up too.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 02-24-2011, 09:13 PM
Member
 

Last journal entry: JB's 37 Pickup
Last photo:
Join Date: Oct 2002
Location: Smoky Mountains
Age: 76
Posts: 2,358
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Copper coils are the best but were out of my budget. Did quite a bit of research on the web and decided that PEC is second best choice. The "experts" claim it has better flexibility for the expansion/contraction of the concrete than the copper, but the copper does have the best heat conductivity. You are going to have zones, whether you want them or not because you want to return the water to the boiler/heat exchanger with some heat still in it. The TEMP Delta does not need to be too wide, or it takes too many BTUs to get it reheated for circulation. In the larger section of my shop, I have three closed loops feeding from one manifold and the smaller section has the same. One thermostat in each section controls the pumps and these thermostats are located about the center of an interior wall. The pumps are 24 volt DC TACOs that have been used in industries for a long time and have a good track record.

Convection heat rises and it is very warm next to the ceiling when it is used. This is really wasted heat unless you want to install a system to return it into the ducts. Radiant heat does have some raising but tends to warm objects. The warm floor means warm feet and very comfortable on a creeper so the thermostat can stay low and still be comfortable. My office/bathroom is located 11 ft up and is not heated. It is about 7-8* cooler than the floor level. We have a small electric heater if we are going to be in the office any length of time and because the office is also insulated inside the insulated shop, it warms up quite rapidly. Of course, you don't linger on the throne if you had not planned your daily constitutional. This spring, we will install a Mitsubishi ductless heat pump in it that will cover our needs

Trees
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 02-25-2011, 09:38 AM
37ford4dr's Avatar
bobs77vet
 

Last journal entry: frame repair
Last photo:
Join Date: Nov 2005
Location: Arlington Va
Age: 57
Posts: 738
Wiki Edits: 0

Thanks: 0
Thanked 16 Times in 15 Posts
to bring the heat down from my 14' cieling area where the electric heater hot air finally winds up i use a slow turning cieling fan that is switched with my lights and an 8" round duct that goes from cieling height to floor with a fan motor in it that is on a timer and every 15min of every hour it circulates the hot air back down to the ground level. this creates a 1* difference in temperature from the cieling area to the ground area. i even use the fan in the round duct when i dont have the heat on and it moves the warm air from the solar radiation back down.. my son actually declared that 8" round duct with the fan in it as one of my best ideas.
Reply With Quote Quick reply to this message

Recent Garage - Tools posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
In floor radiant heating billsnogo Garage - Tools 16 07-16-2014 01:43 PM
radiant floor heat price Garage - Tools 12 08-12-2010 06:39 AM
Floor pan question. Hippie Body - Exterior 0 04-20-2007 08:40 AM
hydronic radiant heat- thats heated water folks. kenseth17 Garage - Tools 1 12-28-2006 09:21 PM
Floor question Rufus_2 Interior 1 12-28-2005 08:35 PM


All times are GMT -6. The time now is 09:19 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.