Realistic Guidance needed for hot water radiant

catia1313

Hey guys--please look at the above pics & tell me if those are steam or HW rads--I need to know!

catia1313

That's what I get for doing my research BEFORE posting!!!! LOL

What has changed?

I have been all over those UK sites for quite a while--then when I read threads on this site you guys warned against it to a guy trying to build his own--that's how I learned of Ecorad in the 1st place, & the reason for the thread & contact with Ecorad.

Harvey Ramer

> @rick in Alaska said:
> Just remember, if you decide to convert a radiator by installing a heating element in it, you WILL need a relief valve installed on it also.
> Rick

Even if it is only filled 3/4 of they way full and not connected to any make up water? Seems pointless in that scenario...

catia1313

Hey--will one of you (or more) please confirm that the pics of the rads I posted are in fact HW rads? They look like they are to me. They look similar to Peerless wall rads from what I've looked up-but --this ain't my wheelhouse. Anything you can tell me about them is GREATLY APPRECIATED!!!!
I need to know before I rent a truck & a man, & make a 9 hour round trip.

Gordy

Steam rads usually only have nipples at the bottom of the sections. HW has the nipples top, and bottom. From the last pic I would say HW.

rick in Alaska

Harvey Ramer said:

> @rick in Alaska said:

> Just remember, if you decide to convert a radiator by installing a heating element in it, you WILL need a relief valve installed on it also.

> Rick



Even if it is only filled 3/4 of they way full and not connected to any make up water? Seems pointless in that scenario...

I would think if you had a closed vessel with water in it, and the thermostat quit and it went to steam, where is that pressure going to go? Unless I am missing something, and this has been a long brain stress week, seems like it would be a must to have some kind of relief.
And I still do not know if those are hot water capable radiators, but it sure looks like they should be.
Rick

Harvey Ramer

> @rick in Alaska said:
> > @rick in Alaska said:
>
> > Just remember, if you decide to convert a radiator by installing a heating element in it, you WILL need a relief valve installed on it also.
>
> > Rick
>
>
>
> Even if it is only filled 3/4 of they way full and not connected to any make up water? Seems pointless in that scenario...
>
> I would think if you had a closed vessel with water in it, and the thermostat quit and it went to steam, where is that pressure going to go? Unless I am missing something, and this has been a long brain stress week, seems like it would be a must to have some kind of relief.
> And I still do not know if those are hot water capable radiators, but it sure looks like they should be.
> Rick

Well, maybe you are right. Although high limit temp switches seem to be the preferred safety method for liquid filled emitters.

If the element is sized to the EDR of the rad, it is impossible for the rad to pressurize to the point of rupture, unless it is thermally insulated.

If a PRV is installed, it must be piped to an unoccupied space or it would have almost the same effect as a pressure rupture in the radiator.

To the OP, it looks like those rads could be used for either steam or water.

Gordy

Fill them with diathermic mineral oil. That's what is in the electric radiator type space heaters. Expensive though.

To the OP curious if those large rads are being used in their present configuration. That's some serious mass to get heated up.

catia1313

Those rads are HW rads, got word from the owner. They were used in the sizes shown. Big old house. The wall rads are 1 column. the short one is 5'x 22", there's a 6'x24", & a 7'x24".

catia1313

So I tried again to get a proper response from Ecorad. I requested that my inquiry be forwarded to someone who would be able provide me with the technical info. Melissa assured me that this time she was answering my questions. My response:

Hello *****,

I’ll try to give you some infromations for comparation electric radiator and a hot water cas iron radiator.

**The major advantage with an electric radiator : each radiator are independent for each other **

Traditional cast iron radiator :

-Need boiler, piping in entire house;

-temperature controled on one thermostat. All of radiator heat even if you just want to heat one room.

-Radiator need to be bleed….

-Maintenant required on boiler, piping, radiator etc.

-System need to be hook-up by plumber

Electric radiator :

-No piping,boiler,etc required.

-Radiator are hook-up on 240v.like a regular eletric baseboard;

-Wallmounted thermotats required.

-Each radiator become independent from each to the others;

-Temperature controled per room by thermostats.Per exemple, you can heat bathroom at 25c degree and kitchen at 20c.

-No maintenant need , bleeding,etc ;

-Radiator are full of anti-freeze and water.Anti-freeze prevent broken cast iron radiator.

-Radiator need to be hook-up by an electrician

In attached files, energy saving with ecorad electric radiators.

I hope it’ll answered at your questions …

Have a nice day

Best

Mélissa Caron
Conseillère en ventes,Sales advisor
418-598-3273 #206
1-855-632-6723
www.ecorad.ca

Spécialistes en radiateurs de fonte
Experts in Cast Iron Radiators
Suivez nous sur facebook- Follow us on Facebook
https://www.facebook.com/ecoradinc/

Here is the attachement-the same advertisement she keeps sending me that does not answer one question:


I cannot make this up.
Truly I am disappointed.

catia1313

I then meandered over to one of the UK sites that sells the heating elements for the cast iron radiators--Take a look at the difference in the technical information they offer their customers-They will even calculate the time it takes for your electric converted cast iron radiator to reach operating temp!!! WOW WOW WOW!!! Now that is customer service!

http://www.castironradiators.ltd.uk/blog/category/cast-iron-radiator-frequently-asked-questions/page/2/

We have sold Electric Heating Elements for some time, but recently we started to put some thought into working out the combinations of heating elements and radiators that will work best together.

We now have a spreadsheet tool that allows us to estimate the time a given radiator will take to reach operating temperature. We can do the calculation for any radiator which we know the weight and water volume of. Here is an example calculation.

Supposed we want to estimate the heating time for a 12 Section Sovereign 4 Column 480 with a 1200W Heating Element.

First we calculate the total weight of iron in the radiator, this is 2 x the leg section weight + 1o x the mid-section weight = 51.2 kg. The total volume of water in the radiator is 0.67 x 12 = 8.04 litres which weighs 8.04kg.

We now use the specific heat of iron and water to calculate how much energy is required to raise the temperature of the radiator by 1 degree. (The specific heat of a substance tells us how many Joules per kg per Kelvin are required to raise the temperature of the substance). The specific heat of Iron is approximately 0.45 KJ/Kg.K and the specific heat of water is much higher at 4.2 KJ/Kg.K.

Multiplying these specific heats by the weight of water and iron in the radiator tells us how much energy is required to heat the radiator through 1 degree of temperature.

Iron: 51.2 x 0.45 = 23.04 KJ / K

Water: 8.04 x 4.2 = 33.768 KJ/K

Total: 56.808 KJ / K

So the energy required to raise the temperature of the radiator (both water and iron) by 1 Kelvin (an increase in 1 Kelvin is exactly equivalent to an increase of one degree Centigrade) is 56,808 Joules. We need to calculate the time taken to heat the radiator through each degree of temperature rise and add all these times together to calculate the total time taken to reach a given temperature.

When the radiator is first turned on, we assume it is at room temperature so ΔT=0 and no heat is lost to the surrounding room. (Remember ΔT is the difference between the average radiator temperature and the surround room temperature). The heat input from the heating element is 1500W, and since a Watt is a Joule per second, the time in seconds to raise the radiator temperature to 1 degree above room temperature is 56,808/1200= 47.34 Seconds. This works out at 0.79 minutes

Now ΔT=1, and the radiator is just beginning to heat the room.

We must now consider the heat output of the radiator. The heat output of one section at ΔT=50 is 62.4 Watts so the heat output of the entire twelve section radiator is 748.8Watts ( at ΔT=50). As the radiator’s temperature rises above the room temperature the heat output increases with ΔT (but not in a linear way). Experiments have shown that the heat output at different temperatures is best modeled by (ΔT/50)^1.3 multiplied by the heat output at ΔT=50.

Doing the calculation shows that the heat output of the radiators at ΔT=1 is just 4.63 watts, the heat available to heat the radiator is 1200-4.62W=1195.37w. So the time taken to raise the temperature by the next 1 degree is 56,808/1195.37= 47.52 seconds.

We continue step by step for each degree of temperature rise. So for example when ΔT=25, the radiators heat output is 0.406 x 748.8 w= 304.1 w, the heat input is still 1200w so the surplus heat available to heat the water and iron in the radiator is 1200-304.1=895.9W. The time taken to heat the radiator by 1 degree is now 56,808/895.9 =63.41 seconds or 1.06 minutes.

By adding all the step times together we can now estimate the time to reach a given temperature. The Heating Elements heat the water to a maximum temperature of 65 C, for a 20C ambient room temperature this corresponds to ΔT=45, and for a 15C ambient room temperature this corresponds to ΔT=50. We assume a room temperature between these values, and therefore give an estimated heating time between the time taken to reach ΔT=45 and ΔT=50. In this case 49-59minutes.

catia1313

This AWESOME calculator will tell you BTUS/Watts etc is from UKAA
& you can do a room calc as well, I didn't post a pic of it because it has some pricing stuff--This lil puppy is AWESOME.

https://www.ukaa.com/cast-iron-radiators/calculator

Zman

No offense intended but that calculator is about useless. It does not have any input for outdoor temp or R-values. It would give the same results for heating a home on the equator or the South pole.

Gordy

Agreed. The more user friendly (less inputs) the program has the less accurate it becomes.

catia1313

Noted on the calculator.
My apologies.
I wondered about that after the fact-& after I played with because it said I needed a 37-40 fin radiator, about 10k btus--for 1 room.

Guess the room by room hardcore ones are the only accurate way.
I don't want to remove/edit it for integrity of the thread.

On another note, after reading the responses here, maybe I will do a DIY electric cast iron rad with the element.
Looks simple as pie, just heavy.
I'd like smaller rad, like for my tootsies under the desk, or a wall one.
I wonder if those electric elements would fit into the wall rads I posted...
I wish I could stop creating projects, but that's just not gonna happen.

hot_rod

If you want to build your own conversion element, you can buy immersion elements in almost any size. This harp I built has a Chromolox 300W with a 3/8" NPT thread, about 4" in length. I contacted a local Chromolox rep, explained what I wanted, they built one and shipped it several weeks later.
If you go with common sizes and voltages they have them on the shelf, they are use mainly in restaurant equipment, warming tables, plate warmers, etc.

You can build a control, even a remote mounted one, add a snap disc for over heat protection.
I also found miniature, stainless steel pressure relief valves, built to you pressure requirement, 1/4" NPT if you want extra protection.

This cast radiator has an off the shelf 12VDC, 1" NPT that off grid solar PV and wind guys use for projects, mostly brewers

catia1313

Hot Rod--you make the coolest stuff.

I don't know what's going on with those wall rads I posted-Initially they wanted 1 price for the lot, now that seems to be changing to 'each'. Think they are surfing the 'interweb'.

concerning CI wall rads-are there any issues specific to them-they are not as deep & smaller-looks like they'd be a good candidate for converting-and a bit lighter to work with.

hot_rod

catia1313 said:

Hot Rod--you make the coolest stuff.

I don't know what's going on with those wall rads I posted-Initially they wanted 1 price for the lot, now that seems to be changing to 'each'. Think they are surfing the 'interweb'.

concerning CI wall rads-are there any issues specific to them-they are not as deep & smaller-looks like they'd be a good candidate for converting-and a bit lighter to work with.

I don't see why any hydronic (hot water) radiator could not be converted. Sheetmetal panel rads are often available as electric units, low fluid volume, low mass. The rev up and down quickly, but no thermal mass if that is what you prefer.

I use regular good quality water in the ones I have built, I've heard mineral oil also works. Some of the electric baseboards and portable electric heaters state "oil filled"

You could probably build or find a PWM control and modulate the element output. The Jaga radiators have a nice small control like that modulates fan speed based on temperature, with the correct relay you could "chop" the wave to the element.

Look at Siesco and Eemax and most any electric tankless heater, they all use some sort of "wave chopper" to modulate the elements. Then you could lessen maybe even eliminate element on/ off cycles.

3.41 X KW= BTU so a 1300W element, which you could run on a 120V 15A circuit would give you 4082 BTU/hr output.

catia1313

hmmm--looking at my oil filled space heating rads--do they sell replacement elements & that control thing that has auto shut off?

My oil rads go 500w, 750w, 1500w & has auto shut off & a temp control that goes 1-7 for which ever wattage I choose.

Looking mostly for premade parts for my 1st try. There is a very well maintained small CI rad close to me 14"x8"x38"

hot_rod

I think most of those radiators have Euro origins and as such would be metric threads. The largest selection of parts and kits I've found are on UK sites, just google electric element radiator conversions, dozens of sites come up.

I don't see replacement parts on the Runtal or Myson sites, maybe contact the factory rep as I know they have electric radiators available.

I have a electric Runtal towel bar in my bathroom, looks like they assemble them in the US, so probably a bunch of the parts somewhere in the US. It is UL listed and that control and element screws into the bottom. I added an electronic T-stat for better control and function.
Sometimes with UL it needs to be sold as an assembly, that may prevent them from selling just the element and control, not knowing how or where it will be installed. Liability you know

Years ago I had bookmarked some US suppliers that were importing those conversion kits, but I cannot find that site anymore.

I would also venture to guess that the factory built element/ controls from most anywhere have to meet some safety spec and would probably require limit switch protection.

The element/ control versions built by Chromolox and others offer manual limit switch options, basically a red button that pops out in case of a high temperature condition, they are just not very attractive for a living space.

catia1313

Time may be on my side for this venture--because *MOST* of the elements being sold are because of advertising converting old antique/vintage style rads--and well, the UK wasn't using metric then, so the elements wouldn't be metric threads right?

Yep, those elements are available on multiple UK sites. Been looking up manufacturers to try to see if any of them are being used here in any products.
If I did purchase one of those elements on UKK's, if the threads were metric- are there converter pieces I'd be able to get here?

Looking at Heatpol manufacturer(Poland)--they make the ones on ukk site & most of the other's I've seen-everyone slaps their name on them.
http://heatpol.com/heaters-for-column-and-aluminium-radiators

The issue now is the length of the element-that little rad I was looking at locally is too small.

This is bordering on, well, ridiculousness at best.


Is there anyway to safely add mass to the electric panel type rads, or liquid filled to get a similar effect of a cast iron rad without compromising it, or is there just no substitute for cast iron comfort?

My oil filled space heaters are wonderful, they just don't hold the heat for very long.

hot_rod

It is really the difference between a dragster and a semi truck. Lightweight panel rads, and heavy cast will just perform differently.

Same analogy for concrete radiant slabs, vs the thin over the top systems.

It really comes down to your preference. Folks that live in climates with frequent and wide temperature swings prefer low mass heat distribution to adjust quickly matching load conditions. Still others prefer the "feel" of high mass and learn to deal with their flywheel effect.

I can help you with metric conversion adapters, that is one of our core products. Worse case a machine shop can modify a US adapter to metric quickly. We have custom size adapters machined locally in Milwaukee all the time for small batch runs. Our factory in Italy like to run minimum orders in the thousands for special sizes.

A good machinist can turn a chunk of brass bar stock into most any fitting adapter in an hour or less I'll bet someone near you owns a lathe!

The length of the probe in an immersion element isn't the big deal as much as it is of sufficient wattage for your need. Generally the higher output elements will be longer or larger diameter, it has to do with wattage density and expected life.

I would guess a large cast radiator would need a 750W or larger to get reasonable response out of it? Determine that from the spec sheet you showed above.

A perfect element would modulate output and never shut down completely, until the end of heating season. That eliminates the startup lag and prevents over shoot when the weather warms and loads drop off quickly. Think of it as a cruise control on the element.

That can be part B of your project, adapting a responsive control. For now spend some $$ get an element in hand and start experimenting. We know the concept works, hence the Canadian company offering the retrofit rads

catia1313

Yes, I need to buy an element. I'm working on it.
Most are longer than I want the width of the rad to be.
Shortest I have found is 480mm(18.8976")

I want this 1st project to be EASY & manageable for me to do by myself.
I just want one of the elements I can screw in & not have to tinker with other t-stat type of stuff.

I also need the rad to be smaller so it is lighter.
I am trying to be realistic.
Truth be told, my dog weighs more than me.
I know how much of a hard time I have lifting her hind end into the truck-& she's cooperating. A hunk of cast iron isn't going to hop into the vehicle & out, then up 25 steps to my front door!

They have elements with a bunch of different settings and a 'freeze protection' are those ones that stay on?

Electronic stuff ain't my thing, I'm out of my element, so want to keep wiring & weight to a minimum for this 1st project, & I don't know what all of the different terms on these elements means.

Also curious-is there any reason these must be hard wired if I keep the wattage 1500 or less? I'd like to be able to give it a run in different rooms & compare it to other types of heaters I have that have the same wattage ,but are forced air/oil rad/ceramic... & also rooms have different exposure insulation/windows etc.
That'd need to be over a couple of weeks each room.

For the 'new' house--I'm now toying with the idea of maybe using different types of radiant for different rooms--maybe elect panels/strip or baseboard for the bath/bed/kitchen where I want a faster response & cast iron electric for the livingroom.

JUGHNE

Most of the cord connected portable heaters rated at 1500 watts, that I have seen, will seem to overheat the cord, plug and outlet if operated on high heat with the temp control set at max.
This is not necessarily a dangerous issue but makes one uneasy to leave the heat on while away.
I always recommend for people to operate on low heat with the temp set at a reasonable adjustment.

In situations like yours I would recommend hard wired heaters at say the main/busy entrance door (for warming boots, coats and that new air that comes in with each entry........the bath room for comfort and freeze protection.
And often overlooked is the basement where the plumbing may be at risk.
Baseboard heaters are the simplest, cheapest and most reliable electric heaters. IMO

hot_rod

I also need the rad to be smaller so it is lighter.
I am trying to be realistic.
Truth be told, my dog weighs more than me.
I know how much of a hard time I have lifting her hind end into the truck-& she's cooperating. A hunk of cast iron isn't going to hop into the vehicle & out, then up 25 steps to my front door!

Lightweight and cast iron radiators are not usually found in the same sentence:)
I'd guess even the smallest cast iron versions will be 100lbs or so. But if you want, like that thermal mass, you will not be happy with sheet metal panel rads or electric baseboard, I suspect.
There were some aluminum radiators around back in the early 90s, mostly imported Euro stuff, might still find those online.

The key to corded appliances is using a cord and plug end that is rated for 20A, a #12 wire, or at least #14 for 15A. Then you should not have a safety or over-heat issue.

You will need to determine what else is on that circuit if you go with a high wattage element, you may need a dedicated circuit for a high wattage element. 20A receptacles are a good idea for high current draw circuits also, they are built heavier.

Larry Weingarten

Hello: I just had a silly and un-aesthetic idea. How about putting an element in the bung of a small, (say 20 gallon) drum? It's lightweight (when empty), inexpensive, has room for an element, and has lots of thermal mass (when full of water), so it will behave more like cast iron. (Pound for pound, water has about ten times the heat carrying capacity of cast iron.) Or, one could just put a thermostatically controlled drum heater on it. Once it's in, put a photo of a cast iron radiator on it so everybody is happy!

Yours, Larry

Canucker

> @Larry Weingarten said:
> Hello: I just had a silly and un-aesthetic idea. How about putting an element in the bung of a small, (say 20 gallon) drum? It's lightweight (when empty), inexpensive, has room for an element, and has lots of thermal mass (when full of water), so it will behave more like cast iron. (Pound for pound, water has about ten times the heat carrying capacity of cast iron.) Or, one could just put a thermostatically controlled drum heater on it. Once it's in, put a photo of a cast iron radiator on it so everybody is happy!
>
> Yours, Larry

I'd be worried about the pressure rating of the drum. It doesn't take much to make them go round, especially when you're heating it.

Gordy

After the first electric bill, over heating won't be an issue........

Larry Weingarten

"I'd be worried about the pressure rating of the drum. It doesn't take much to make them go round, especially when you're heating it."

Hello, I imagine that could be taken care of by not filling the drum completely... leaving room for thermal expansion. It still might not be pretty though

Canucker

It would be ugly. The sun makes them ovals here when the bungs are left sealed on the empty drums. The cold pretty much flattens them when they get put outside in the winter after warming to room temperature. Makes a heck of a bang. Haha

hot_rod

I built a bunch of clear plastic pumping displays to demonstrate dirt and air removal. I worried that running the pump for hours would cause a pressure increase and pressure problems.

I found this company that builds mini pressure relief valves to your spec. I bought some 1/4 SS at 5 psi.

You could add these to an electric radiator conversion, or any vessel that you wanted pressure protected.

I would still include a high temperature limit, simple electric water heater element controls seem reliable for temperature and high limit control.

catia1313

LOL Larry-That'd be called a 20 gal hot water tank.
Putting it in my living space to get the residual heat while working double duty as a storage tank is NOT a bad idea in the least!
I know you meant it to be facetious, but that is actually being considered already. Fact is: Hot water storage tanks are expensive to run. It produces & loses BTU's. The point is to use the BTU's lost while standing. For efficiency purposes, it'd be two fold on the positive, lessening the load needed to heat the water & giving off heat. Since this is a small house with a low amount of BTU's needed, it needs to be incorporated, but that's a topic for a different day.

Currently I am wanting to convert a CI rad filled with water to an electric fueled rad. I was just curious if there was a different way to add mass using a lighter type of rad.

Question:
When looking up the weight of sections of new CI rads for reference purposes:
the 19" & 25" tall rads, 4 column, were about 7-8lbs/section. Were the older rads heaver/thicker ci or is it about the same?

If I got a small rad, 2-4 column, say 6-8 sections, empty, it should be under 100lbs by those #'s.

My thought for this initial experiment was:
If I can get a smaller rad of about 75lbs, I can strap it to the dolly & get it up my steps by myself. That's what I am meaning by "lighter"-something about 75lbs.

The types of elements UKK carries (Heatpol)-the smallest being about 19" & needing additional 2" minimum internal space to accommodate. Per the specs-I looked it up (heatpol).

The rad I choose for this project/experiment needs to be minimum 21" internally for the element to be properly installed/spaced. Of course I'm not wanting to be at the lowest end of the spectrum, but it gives me an idea of what size rads to consider.

Yes, I am aware I probably won't be as pleased with the comfort of a non CI rad, but in the smaller rooms where I spend less time like bathroom & kitchen, it seems to be more difficult to find small CI rads-especially 2 column, or even wall rads that are small, at least in the USA. UK seems to have more options on the small end.

Larry Weingarten

Hello, Let's do a little mathematical rambling One cubic foot of fresh water weight about 62 pounds. One foot of cast iron weighs about 450 pounds, telling us that CI weighs about 7.25 times what water does by volume. But water holds ten times more heat per pound than CI. What this seems to say is that as long as the vessel holds enough water, it can be low mass (read lightweight and easy to manage!) I've been doing some research on heat loss in plumbing. Surprisingly, although copper conducts heat many hundreds of times faster than plastics, plastics are better radiant emitters than copper... like nine times better! And of course, copper is a better emitter than CI. What this leads to is that you could build radiators of large PVC pipe if you wanted, and they would do the job. Also, if you had a lower manifold of, say 4" PVC, it would be an easy place to put an element... as long as you had very good thermostatic control! Paint your new "radiators" flat black, add some of Hot Rod's relief valves and you're cooking.

Yours, Larry

catia1313

Interesting. Isn't PVC sensitive to temperatures above a certain degree? Not saying in theory the idea wouldn't work, because most things full of heated water would heat, but I doubt the longevity, otherwise it'd be on the market as someone's product. I'm not seeing any pvc radiators or hot water tanks or similar items on the market.

Plus, I've seen the pics of the emitters with pex & aluminum emitters versus copper with the same emitters-there was no contest, copper to aluminum was better. Maybe that's a conduction issue-either way, I'm sticking to tried & true technology that has a known track record.

The reason I want cast iron rads specifically is for the comfort factor of their 'residual' heat. I have a medical condition that causes me issues with regulating my body temperature. Certain types of heat just are not as comfort friendly for me. This causes me serious issues in my day to day life. If it were not for my medical issues, I'd not be going down this road because certainly there are other solutions that are easier for a small house with a low BTU load.

Mark Eatherton

You guys are making the liability hairs on the back of my neck stand up.... No operator, no high limit, no LWCO... I guess I've been hanging with too many lawyers. And God forbid, if something DID go wrong, and the insurance company comes in to investigate, you will most probably have no insurance coverage either. Proceed with caution.

If it were me, I 'd look at some off shelf electric heating systems (electric cable or film type) imbedded in two layers of sheet rock. Got your radiant, got your thermal mass flywheel effect, maintain insurance coverage and comfort.

ME

Larry Weingarten

Hello, I'm not going to disagree with Mark. I like to understand the properties on materials and tinker with stuff. I've no doubt safe equipment could be built, but those who come later might figure out how to operate it wrong. It might make sense for catia to hire some more muscle help out to place radiators so we're not having to fight that 75 pound limit. Don't want Mark's liability hairs getting too excited!

Yours, Larry

catia1313

don't worry, I'm not talking doing my whole house, these elements are on the market, not a home made job. I was going to buy one electric CI rad from Ecorad but their customer service won't provide me with any answers. I tried multiple times & the woman will not forward my info to someone else--I asked. nicely.

The elements are made by Heatpol
I'm only building 1 small rad. Er I mean I am only converting 1 small rad. Not building anything in reality. The elements are pretty nifty.

http://heatpol.com/hgt-electric-heater#opis-dzialanie-t