Floor Heat help!!

[Flatblk1]

We'll to start I will fill you in with what I have going in. I built a shop this summer it is 36x48 with 12 ft side walls and vaulted scissor rafters, I beleive the center of the ceiling is about 16 ft. It is all 2x6 construction and will have roll in r-19 in the walls and at least r-45 blow in in the ceiling. I used icf forms for the pad, I put down 2" insulation with 8 loops that are 220'-240' long then 2" of sand covered by a 5" slab. The tubing is about 6" apart around the perimeter and they gradually become about 12" apart in the center. I have two overhead doors one is 10'x10' and one 10'x12', they are insulated doors rated at r18.5. It also has two 36" walk in doors and four decent 24"x36" sliding windows( I know I should have got crank outs).
I am in the process of wiring it so I can get it insulated (it is starting to get pretty cold here in North Dakota). So I've been reading in here and looking at other sites to find which electric boiler I need so I know what size of wire to run to my location from what I have found I need about 75000btu's. This is fine and I thought I had it all figured out and needed to run 2 runs of 6-2 wire for two 60 amp breakers. Right??
Here is where I get thrown for a loop. My neighbor had a shop built this last year also his is 34x52 and has one 10x16' overhead door rather than two smaller ones otherwise it is built identical to mine. The reason I know they are built the same is the contractor who built his is a friend of mine and helped me with mine.(and I helped him a little with the neighbors). Anyway he went to the local electric coop and purchased what they recommended for this shop and had them install it. They put in a 10kw, 34000 btu electo-boiler. I thought right away that I was glad I did some research and mine was going to work better and he was going to want to upgrade but, his works great!! He keeps it set on 60, it's very comfortable, it's not hardly ever running even the last few nights when it's been down around zero! I was going to wait and see what his elec bill is going to be but u kinda wat to get mine wired. So is his too small or was I thinking too big? Any help would be appreciated!

One more question if someone knows, do I need to run a 20 amp circuit for the circulation pump or can you power them off of the boiler?

Thanks for any input!!!!

 

[anthony666]

you guys and your electric boilers !! arggghhhh !! propane is not an option ?? natural gas ?? wood boiler ?? even wood boiler with electric back up ?? geothermal from a well or a pond

firstly .. contact a local heating design guy and pay the money for a proper heat load calculation based on your location, the building design, design temperature etc .. only then will you know definitively what size boiler you need .. if you're gonna base your decision on anecdotal, shade tree, guesstimates you may as just choose the boiler based on if the color of the case goes with your tool boxes .. it's still only the shoulder of the heating season

slant fin is a good brand name

circ pumps draw very little current, you don't need 20 amps

why the sand ???

 

[Flatblk1]

I have natural gas 100' away talk me into it.


(slant fin is a good brand name)

What color are the slant fins?

(circ pumps draw very little current, you don't need 20 amps)

I guess I was wondering if I separate circuit or if I could run it off of the boiler?

(why the sand ???)


I'm not sure some guys do it here some don't, I don't know what it does but my concrete guy said he would prefer the tubes to be covered so I did it. He told me most of the commercial jobs he does has 4-5" of sand on tubes before concrete.

 

[koditten]

I want to know about the sand as well.

Is gas not an option? I don't care how cheap your electric is, that is going to kill you in electricity costs.

With that said I really can't help you. I use a conventional boiler. They make unlimited amounts of hot water, that's what they are designed to use.

I don't believe you when you say its hardly running, Wait until we get into the single digit temps. That electric meter is not gonna be sitting still much.

We do really want to help, but you need to do your homework. Find out what the BTU loss for the structure is and we can go from there.

 

[koditten]

If you got the gas, don't even think about the electric. A gas boiler will last way past your lifetime. I spend a lot of time on this subject. Ihave heard of very few gas boiler failures, but lots of electric element failures on electric boilers.

Running the gas line is not going to kill you. The yellow, plastic gas line is cheap. The only thing spendy is the metal risers on both ends. It only needs to be in the ground 18" in most places.

If you really want to save some money, do like I did. I found out my BTU requirements and started to look for a used boiler. They are pretty common. I found one for 250 bucks, took one of my friends that is in the buisiness check it out and bless it. I gave him $100 giving me the green light. In most cases boilers are good or they are bad. Everything else is cosmetic.

I found my boiler on CL. The new owners of the home wanted forced air, so the 10 yr old boiler came out. It's quite common.

I also went hunting for a conventional boiler with a standing pilot light. There are only 4 things that can go bad with a boiler that has a standing pilot. Thermocoupler, gas valve, relay and the aquastat and of course a cracked exchanger, but that wont' be an issue if the boiler is set up to run at the proper temperature. Most of these things can be picked up at the local HVAC house. A standing pilot boiler usually has no circuit board, another reason I wanted this type of boiler.

My shop is used a fab shop, so an open pilot flame is not an issue. I'm welding and cutting already.

 

[anthony666]

The new owners of the home wanted forced air

that makes me hear the theme music to the flintstones

 

[anthony666]

I have natural gas 100' away talk me into it

koditten already made all the pertinent points .. it's cheap and reliable

What color are the slant fins?

lol jerk

I guess I was wondering if I separate circuit or if I could run it off of the boiler?

you can piggy back off the same circuit as the boiler .. makes it easy to have one single switch to shut everything down

4-5" of sand on tubes before concrete.

i've been doing radiant too long and i've never heard of that before .. as the tubes heat they expand, and as they cool they contract .. if it's embedded in concrete it isn't going anywhere, but sand might let it move and abrade, or even kink .. if i was you i'd contact the pipe manufacturer asap and find out if they'll honor their warranty under those conditions

 

[Highbeam]

I am planning to use an electric boiler for my 1800 SF shop in a much milder climate. I am only planning on using the system for freeze protection but want to be ready for future upsizing so when I ran the wires to the boiler location I used 1" conduit and Stranded wire. I used 8 gauge wire for a 50 amp boiler service. Additional future proofing included running a line voltage thermostat circuit to the boiler, this allows a thermostat to turn an outlet on and off. I also ran regular thermostat wire between the stat location and the boiler.

What I'm saying is use conduit. You can then change your mind on the boiler circuit size down the road.

I chose electric because we have no NG available. NG is typically much cheaper than electric. I did run the numbers with propane and found electric to be cheaper, easier, safer, and more dependable. If I thought I needed 70,000 btu then I don't think I would have much choice but to use gas.

If NG is available, even at several hundred feet then use it.

 

[tdkkart]

There's not a thing wrong with electric if it works for you. Yes, it's more expensive than natural gas, and is slightly more than propane, SOMETIMES, depending on where you are located.
However, for shop heat it is considerably safer IMO, no open flames to ignite fumes from chemicals, no carbon monoxcide issues, it's quiet, reliable, takes up no floor space, requires no chimney, and needs zero maintenance. My fully electric system has been running for 5 years with not one single hiccup, and cost considerably less to install.

 

[Flatblk1]

I'm considering using natural gas now but yeah I was going to use electric because it is easy, quiet no exhaust needed and I work at a coal mine! I'm still not quit sure what I'm going to do but thanks for the help so far. I wish there was an easier way to calculate btu's needed.

 

[Highbeam]

I wish there was an easier way to calculate btu's needed.

Don't we all. If you use five different "btu calculators" you will get five different answers that usually have a huge spread. Just do your best and guess.

With electric there is no real punishment for oversizing, the thing just runs less often. With gas, the short cycling is a big problem.

 

[Flatblk1]

If I were to go to natural gas what boiler do you guys recommend? And where can I get one with he whole pumping board and everything I need? I guess the same goes for electric, what are your opinions in the seisco boilers?

 

[Flatblk1]

One more question I have is if I am using an electric boiler how does off peak work with it and does anyone know what I need to rough in an off peak meter?

 

[anthony666]

With gas, the short cycling is a big problem.

there are ways to deal with that problem

 

[Flatblk1]

Does it help that I can get off peak electricity for $.041/kW?

 

[Rickcnc]

Does it help that I can get off peak electricity for $.041/kW?

Does that include all additional charges the utility company tack on, here in Ontario with all the charges added it's in the $.15/KWH range

 

[HoosierBuddy]

It's sort of off topic...but if I ever need to go with an electric heating solution, the only one I would consider would be heat pump based. You're looking at a COP of 3 to 4 vs. a COP of 1 for any sort of electric resistance based heat (like an electric boiler).

Crazy savings to go with a heat pump plus it would give you ac in the summer.

Natural gas is still cheaper...but propane prices might lead you to a hybrid system. You'd have to run the numbers.

Phil

 

[Highbeam]

It's sort of off topic...but if I ever need to go with an electric heating solution, the only one I would consider would be heat pump based. You're looking at a COP of 3 to 4 vs. a COP of 1 for any sort of electric resistance based heat (like an electric boiler).

Crazy savings to go with a heat pump plus it would give you ac in the summer.

Natural gas is still cheaper...but propane prices might lead you to a hybrid system. You'd have to run the numbers.

Phil

They don't make a heat pump water heater. Well one brand does in Europe but it is not marketed here. I think it is a conspiracy. A real inverter heat pump would be awesome at heating water for domestic and for radiant heat.

 

[anthony666]

They don't make a heat pump water heater. Well one brand does in Europe but it is not marketed here. I think it is a conspiracy. A real inverter heat pump would be awesome at heating water for domestic and for radiant heat.

yea dude. they do .. i just did my certification in rheem & stiebel eltron ambient heat pump water heaters

plus all those geothermal type water to water heat pumps .. fhp, bosch, water furnace etc etc

 

[Flatland Dave]

Talk to the co-op about what it will cost to run the second meter etc. As far a the electric boiler set up, find a HVAC outfit that does these. I suppose they will sell you one they build if you want to do a diy. Or you can go Menard's and put one together...

I plan to run electric boiler in my 32 x 48 x 16. That is what was planned in the beginning.

Natural gas is not everywhere. If he has co-op electric, chances are he is somewhat rural. Propane was an option for me, but didn't go that way.

 

[tdkkart]

Propane was an option for me, but didn't go that way.

The problem with propane is that it has, and will again, take wilder swings in price than even gasoline does. I'm really surprised it hasn't this year as there were alot of shortages around here during corn drying time this fall.
Once Propane gets over about $2/gallon it gets very close to electric depending on exactly where you're at.

 

[HoosierBuddy]

They don't make a heat pump water heater. Well one brand does in Europe but it is not marketed here. I think it is a conspiracy. A real inverter heat pump would be awesome at heating water for domestic and for radiant heat.

What I was advocating (off topic, I know) would probably lead to an air-source heat pump solution, either a standard or mini-split instead of in-floor radiant. I mean, I LOVE my in floor radiant....but I've got natural. If (in 2006) I wouldn't have...I'd have been all over a heat pump.

The geothermal or new-fangled-water-heating unit$$$$$ wouldn't make my cut in a home garage situation. Simply too much cash outlay for not enough payback. A well insulated garage set at 50-degrees won't generate payback like a home will at 72-degrees, especially if it has lots of windows and doors.

For a garage with electric as your source? Man...I have to think I'd be all over a mini-split...even two of them if one wasn't big enough.

Phil

 

[anthony666]

a mini split is gonna be running on electric elements at juncture in the heating season .. at least at my latitude .. a general rule of thumb is that doubles the heating cost

geo; agree, too much buy in for a garage space .. unless you already have it in the house or you have an handy unused well or something similar, and run an open loop .. this scenario is cheaper and more feasible than most people think

ambient air heat pump used to heat the ambient air temp in a space .. can anyone else see the glaring flaw in this idea ???

 

[walrus]

They don't make a heat pump water heater. Well one brand does in Europe but it is not marketed here. I think it is a conspiracy. A real inverter heat pump would be awesome at heating water for domestic and for radiant heat.

GE makes ones but my recommendation would be one made in Maine by Nyle Corporation, it will retrofit onto any electric hot water heater or any tank you have. I have a Nyle and it saved me 30 bucks a month and paid for itself in a couple of years.

here is a link
http://water.nyle.com/

 

[BadgerBoilerMN]

First,

You size a boiler to the load, determined by the long accepted ACCA Manual 'J' heat load performed by an experienced designer/contractor (no he doesn't have to be local, since the standard originates with ASHRAE).

Once you have the size of the boiler you can choose the fuel source. This is usually done in a rational manner avoiding heresay and the anecdotes of your local tribe.

In N. Dakota there are considerable savings to be had in the "off-peak" rates offered about half of the day--mostly at night. To get around the long off-times, one of the ancients decided if he embedded the PEX tubing deep in the ground/sand, it would create a heat-sink (not a very good one) and thus would be more comfortable and the heat "stored" in the sand would hold him over until the next time the power company flipped his switch again. I guess if you are used to an unheated quonset this would be like heaven.

I would rather super-heat a storage tank and draw what little I needed in the off-peak and be able to burn some wood as well, but this would take some engineering.

If you have natural gas, buying an electric boiler is never a good investment, since the best off-peak electric rates are typically 10-20% above natural gas and likely will be for many years to come.

I would, and do, install the smallest gas-fired condensing boiler with outdoor reset, standard equipment.

Of course if you don't want to hire a professional, maintain your boiler or cut your fuel bill in half an electric boiler really can't be beat. It is cheap to buy, cheap to maintain and will keep you more comfortable than the guy with a scorched-air unit heater ever dreamed of.

Buy the way, "sand" is not an accepted substrate for foundation or slab and a poor heat sink as well. "John 3:16" Rethink the custom and get some science behind your decision making process. Follow this link to a simple explanation. If you could use a more technical study, contact me directly.

http://www.bobvila.com/posts/38601-slab-substrate

Most of our work is designing and installing radiant floors with natural gas-fired condensing boilers, but I own an electric boiler since the power company here offers "interruptable" power at 4 cents, less than LP, and naturally gas is not available.

Go figure...

 

[Highbeam]

GE makes ones but my recommendation would be one made in Maine by Nyle Corporation, it will retrofit onto any electric hot water heater or any tank you have. I have a Nyle and it saved me 30 bucks a month and paid for itself in a couple of years.

here is a link
http://water.nyle.com/

That's not what we're talking about. Those tank top things steal heat from the indoor heated space to heat water inefficiently. A mini-split heat pump water heater would actually use heat from the cold outside air to heat water with a much more efficient and dependable compressor.

Mini-split heat pumps for air heating have been steadily improving and the good ones can now deliver 100% of their rated output at 5 degrees above zero. 85% below zero. There is no longer any need for backup resistance heat unless you live in a place crazy enough to sit at below zero temps for long periods. Even then, output is only reduced until -15 degrees where they kick off to avoid damage.

 

[walrus]

That's not what we're talking about. Those tank top things steal heat from the indoor heated space to heat water inefficiently. A mini-split heat pump water heater would actually use heat from the cold outside air to heat water with a much more efficient and dependable compressor.

Mini-split heat pumps for air heating have been steadily improving and the good ones can now deliver 100% of their rated output at 5 degrees above zero. 85% below zero. There is no longer any need for backup resistance heat unless you live in a place crazy enough to sit at below zero temps for long periods. Even then, output is only reduced until -15 degrees where they kick off to avoid damage.

Not sure how its inefficient in the summer when its air conditioning living space and dehumidifying my basement. I can see your claim in the winter but in my case I heat with a woodstove, throw a few more sticks on and I get my hot water. Most folks around here shut them off in the winter, I don't.

keep watching the Nyle website, they are close to a heat pump boiler. Lots of hot water baseboard heat in the New England, thats what they are close to putting on the market, a retrofit for a oil fired boiler. Should be within a year

 

[Highbeam]

Not sure how its inefficient in the summer when its air conditioning living space and dehumidifying my basement. I can see your claim in the winter but in my case I heat with a woodstove, throw a few more sticks on and I get my hot water. Most folks around here shut them off in the winter, I don't.

keep watching the Nyle website, they are close to a heat pump boiler. Lots of hot water baseboard heat in the New England, thats what they are close to putting on the market, a retrofit for a oil fired boiler. Should be within a year

Walrus, this thread is about a shop. No basement. Any heat you steal from the room to heat water must be replaced by the hot water. Can't you see why this is a bad idea? Further, there is an endless supply of energy in the outside air that can be extracted by a heat pump. The air to air guys have this technology figured out very well.

Any heat pump that extracts heat frpm the conditioned indoor space is pretty dumb. Let's hope nyle can get that right and split the system.

I'll go review their site right now.

 

[walrus]

Walrus, this thread is about a shop. No basement. Any heat you steal from the room to heat water must be replaced by the hot water. Can't you see why this is a bad idea? Further, there is an endless supply of energy in the outside air that can be extracted by a heat pump. The air to air guys have this technology figured out very well.

Any heat pump that extracts heat frpm the conditioned indoor space is pretty dumb. Let's hope nyle can get that right and split the system.

I'll go review their site right now.

I understand why you think its a bad idea but in southern climates where air conditioning is needed more times out of the year than heat, its not a bad idea to use the heat of your house to make hot water. Its not even a bad idea 6 months out of the year in Maine.
Nyles boiler is a split system

 

[walrus]

Got some info on Nyles heat pump boiler, it will get water temps 100 degrees over outdoor temps. Probably not hot enough for typical baseboard systems but should be fine for concrete radiant systems, I'll have more info in a week, friend is installing a beta site

Sent from my XT901 using Tapatalk

 

[Highbeam]

Is it a real split system with an outdoor unit and an indoor heat exchanger? The Daikin Altherma is the only other current model and they are getting bigger in NA since acquiring some other NA brands.

A large portion of american's energy bills are from heating water with very inefficient methods. Inefficient in terms of cost or actual waste. I'm no tree hugger but the low hanging fruit of home heating is taken and there are some serious opportunities in water heating being ignored.

The Daikin system looks great but is very expensive and overly complicated.

Thank you walrus and please post up another thread.

 

[Highbeam]

GE makes ones but my recommendation would be one made in Maine by Nyle Corporation, it will retrofit onto any electric hot water heater or any tank you have. I have a Nyle and it saved me 30 bucks a month and paid for itself in a couple of years.

here is a link
http://water.nyle.com/

They'll have to do better than that geyser. Not impressive. COP of 2 vs. MSHP heat pumps that heat air with a COP of more than 4 so the Nyle wastes 50% of the energy that the MSHP can make with cold outside air.

They are 60 dB which is louder than my gas powered generator. Sheesh, loud! and must be inside. Just what I need starting and stopping while I am trying to sleep.

 

[walrus]

Yes, outdoor unit, very heavy, indoor heat exchanger and contols

Sent from my XT901 using Tapatalk

 

[Highbeam]

That's great, nyles seems to offer just the right thing in their CCHP (cold climate heat pump). I wish them well and hope that the price is reasonable. COP of 3-4 so for every watt you pump into the thing, you get 3-4 watts of heat for your floor. In other words, the 10,000 watts you are pumping into a hydroshark on the wall will get you 30,000-40,000 watts worth of heat!

 

[walrus]

That's great, nyles seems to offer just the right thing in their CCHP (cold climate heat pump). I wish them well and hope that the price is reasonable. COP of 3-4 so for every watt you pump into the thing, you get 3-4 watts of heat for your floor. In other words, the 10,000 watts you are pumping into a hydroshark on the wall will get you 30,000-40,000 watts worth of heat!

Nyles real business is drying lumber, they were the first around here to use heat pumps to kiln dry wood. They have lumber kilns all over the US. The guy that owns the company is pretty smart and has many patents on Cold Climate heat pump related items. My guess would be the boiler is going to be pretty expensive? The beta site is a swimming pool, they are looking for 85 to 88 degree water in the pool.