Infrared heating panels

[Beno]

We are designing our next ICF home (Ottawa, Canada). The primary heater will be VC cat fireplace (Sequoia). I consider to install as backup heaters Infrared heating panels, mounted on ceiling. Anyone has experience with Infrared heating panels ?
Are they efficient in a cold winter? Or should I go with regular electric baseboards?
Thanks,
Beno

 

[Sandor]

This is really on time!

I am building a small ranch home that I would like to be energy efficient and I have seen these also.

The concept sounds great.

Which ones are you looking at? I'm looking at these....


(broken link removed)

 

[Beno]

Do you know what is the price of the panels? Do you plan to put 1 or 2 panels in every room?

 

[begreen]

My father installed electric ceiling radiant heat in a large bedroom addition in our house, back in the early 60's. The effect is really pleasant, it feels like sunshine. I don't think they sell this product anymore. I think it was built into the sheetrock panels.

 

[Sandor]

Beno,

The floor plan has a 16X26 Great Room/Kitchen, with a Cathedral Ceiling. I was going to put 2 on either side for a total of 4. 1 in the bath, and 1 in each bedroom.

BeGreen,

That is the selling point about these panels. Its supposed to feel like sunshine... supposed to be very comfortable at a lower temp. And they do look like sheetrock panels.

 

[Highbeam]

It is tough to swallow their marketing schpeel when they say that they are more efficient than wall heaters. How can that be? The wall heater is 100% efficient. What they really mean is that you don't need to heat the room to the same temperature to feel comfortable thereby saving energy compared to a wall heater. When I start sensing a snake I worry about the whole concept. They share many of the adavantages of wall heaters such as zoning and no duct losses with the benefit of silence and flexibility in furniture placement. For instance I can't put a towel rack in one of my bathrooms because there is a wall heater in the spot.

These are 220 volt appliances according to their amp listings with relatively low power draw per room. I wonder though, since the radiant heat will stop as soon as the panel turns off due to the low thermostat setting, will the room immediately feel much cooler (its true temp) as though a cloud moved in front of the sun?

At first I thought that individual room heaters was a cheap-o way to build a house. It certainly is cheaper than installing a furnace. I now see that there are some distinct energy saving benefits.

 

[Sandor]

At first I thought that individual room heaters was a cheap-o way to build a house. It certainly is cheaper than installing a furnace. I now see that there are some distinct energy saving benefits.

Can you clarify this paragraph?

 

[restorer]

A few years back, friends in Idaho bought a radiant heated house. It took one Winter for them to install a wood stove and two Winters to get enough together to pay for a new install LPG central forced air heating. Ther payback for the install is five years from the electric savings. I can only think the issue is as always, you need x number Btu's to heat, fuel source and appliance have a bearing, but those heaters do not do any better percentage than a very efficient gas appliance, a bit better than wood stoves or pellets, but at what cost. It only takes one $1,200 electric bill to get some to wake up and smell the roses.

 

[begreen]

BeGreen,

That is the selling point about these panels. Its supposed to feel like sunshine... supposed to be very comfortable at a lower temp. And they do look like sheetrock panels.

The old style actually was embedded in the sheetrock. Or another design at the time was that one put up the first course of sheetrock, then carefully installed the wireloops, then a thin layer of mastic, then another layer of sheetrock to create a sandwich with the heating coils in between. My dad went for the easier method. They were 240v but relatively low wattage compared to todays product, so one did most of the ceiling with them.

 

[Highbeam]

At first I thought that individual room heaters was a cheap-o way to build a house. It certainly is cheaper than installing a furnace. I now see that there are some distinct energy saving benefits.

In today's dollars with today's technology and assuming of course that you are off of the NG grid which I am.

It is cheaper to build a home with individual heaters. The heaters are 1-200 dollars apiece and wiring is standard 12 gauge 220. Compare to a central system which has been quoted on this site to easily touch into the 5 figure realm.

I now see that there are some distinct energy saving benefits. One energy saving benefit is that you do not lose 30+% of your btus to duct losses. You are able to selectively heat each room to different temperatures and at different times of day. This zoning would give significant savings over a whole house furnace which heats the whole house at the same time. The electric heaters, as an electric furnace, is 100% efficient utilizing a fuel that is now competitive on a BTU basis with LPG.

It is hard to beat 100% efficiency delivered without any duct losses automatically to a single room from a cheap appliance using a relatively cheap fuel. These little wall heaters are simple and can be bought from a local hardware store and installed by a regular person.

Tell me where I have missed the boat. I am about halfway through upgrading my wood stove and love to have a goal to work towards. One of my goals was a central furnace but I have decided to stick with the wall heaters since it is hard to justify anything else.

 

[Beno]

I don't understant what is the difference between the wall and the ceiling infrared panels. They should be the same product that you install anywhere you want. The ceiling location is better in my view because leaves the walls free and the floor (that has a higher thermal mass than the vertical items in the room) can absob the radiation and radiate it back (just like the sand on the beach, on a sunny day ) .

 

[Rhone]

Don't go electric baseboards, radiant energy is the single most important factor in determing comfort, not air temperature. For every 1 degree of mean radiant temperature you need to raise the air temperature around 1.4F to compensate. That is, if you're in a room whose mean radiant temperature is 70F and air temperature is 60F, to feel the same comfort if the mean radiant temperature is 60F you'd need the air temperature to be 74F to feel the same. I'd stick with working on radiant energy. The only thing that conerns me is floor vs. ceiling. The ceiling argument is, there's less air movement, also drywall is an excellent medium for transferring the energy quickly and isn't cluttered whereas radiant floor heating under a wood floor, or under a rug, or under cluttered floors reduces the effectiveness vs ceiling. Floor however puts the heat where people like it most, their feet. The other issue is that radiant energy follows the inverse square law which states the power intensity per unit area from a point source, if the rays strike the surface at a right angle, varies inversely according to the square of the distance from the source. That is, for every doubling of the distance the amount of energy hitting the same area is 1/4th as much. Explained another way if you have 9 foot ceilings, and your head is 3' below your waist will get 1/4th as much energy as your head, and your feet 1/9th as much. There's a little more to it than that, as the radiant energy being released by the ceiling will normally hit the floor and obstacles below and warm them up as well and they in turn will release radiant energy back so there isn't exactly as much drop off as that in real life.

But the situation was brought up, when it's shut off does it feel like a cloud just passed over your sunlight. It does since ceilings have minimal heat storage. When shut off, a person underneath will usually feel as if they're in 4F colder temperatures (even though air temp didn't change) within 20 minutes.

I personally spend about one month a year in a super efficient house with a solar radiant floor heating system, with insulated blinds, triple pane windows, no windows on the north side, super large ones on the south. I can't really help with my experience, the slab takes 2 days to cool off not 20 minutes. I also can't account for how much heat is from what, whether it be from the slab charged up by the solar, or the large south windows, even cooking a dinner in that house when it's 5F outside raises the temperature in the house about 4F and takes several hours to get back down to normalized temperature.

 

[Beno]

Your solar radiant floor, I guess is a hydronic system which heats water solar + electric? Can you please provide few details about this?
Thanks,
Beno

 

[Rhone]

The house is a Gambrel which has 3" foam XPS (R15) on the sides of the slab, and 2" XPS foam (R10) insulation under the slab. Then the slab is 24" thick of compacted sand, and another 5 1/2" of cement on top (29 1/2" thick total). The PEX runs through the slab at 2 levels, it runs through the 5 1/2" of cement first and then loops underneath into the compacted earth and heads back at alternating depths. I included pictures to help show what I mean. For solar the house has eight 4x8 solar collectors that run glycol, two are always hooked into heating water in an 80 gallon storage tank for domestic use, and the other 6 are hooked into charging up the slab during winter but there's a valve that lets you shut off charging up the slab and divert all 8 panels into charging up the 80 gallons for domestic hot water (in summer). The 80 gallon water tank does have electric backup. The 6 windows on the south side are double-pane non-coated (which allows the most heat gain) low air infiltration windows 3' x 5'. With them uncoated they gain the most possible energy when the sun is out, but it works both ways they lose a ton when it isn't. So, insulated blinds must be used. The whole house has roman blinds made of foil faced bubble insulation, with strips of magnets sown on the very edges, and the whole thing covered with a thin layer of padded quilt, and a heavy metal bar for the bottom weight. They're around 1/4" thick, and the windows are dark stained and have magnet strips fastened to the trim (hard to see with the dark stain). When you pull down these roman blinds, you have to pull them away from the window and then when in position bring it close to the window where the magnets inside the blinds suck to the magnets on the window trim creating a tight seal. The weight of the metal bar on the bottom keeps it tight against the bottom of the sill. The south windows let sun shine on the slab to store energy. The house has 4 windows on the East & West sides per floor which are triple pane and less than 3' x 3', and also have the same blinds, and no windows on the north. Low-E Argon double-pane glass windows will do the same as triple pane and cost less. The walls are 8" thick with fiberglass batt insulation and the attic is R30 but today you'd use 4" thick walls filled with wet blown cellulose with 2" XPS or Polyisocyanurate insulation covering the entire outside, and probably just blow R45 in the attic. The house is a Gambrel to minimize the number of windows on the second floor without sacrificing looks and the extra "roof" part that normally Gambrels have on the sides is pitched for the angle and hold the solar collectors. There is no attic. The second floor only has 4 windows, 2 on the east and 2 on the west. There is no heating on the second floor either, it maintains around 66F, but the room with the chimney running through it if the stove is going is warmer. The house had a single 10' long electric baseboard for backup on the first floor which kicked on a dozen times a year, but about 4 years ago a VC Encore cat wood stove was hooked into the central chimney and it now is the backup, the house is occupied all year and goes through 1/2 cord of wood as the people occupying it like to keep it around 78F and situated in Central/Northern VT. Once you engage the slab, until it reaches 30F outside during the day you have to keep windows open because it gets too hot otherwise. Once the temps outside drop to below 0F for over 3 days, or it gets cloudy for over 2 days usually a fire is lit in the Encore. As a test we didn't use any backups once during a spell of temperatures below 0F. After about 3 days the house settled and maintained 65F at night and 68F during the day.

 

[Mo Heat]

Do those ceiling radiant heaters differ from this thing I picked up at the hardware store (see: photo)?

It is billed as a convection heater and the instructions insist it be mounted on a wall, with one inch clearance, to allow air to convect behind it. It's meant to set up a circular flow, but that assumes you mount it on a wall. I mounted mine on the kitchen island to allow me to lower my forced air NG furnace, and still not hear complaints at breakfast.

Mrs. Mo Heat and Mother Mo Heat occupy the island chairs. I can tell you, it not only convects, but it also radiates. Of course, sitting so close to this thing, it would be hard to not stay warm.

It is 110V and about 500Watts. If I left it on all the time, it would cost a fortune. Even with a kwh costing about 5.6 cents here (soon to go sky high BTW), I figure it adds about $15 per month (edit correction: only adds $7.50 per month) to the electric bill, and that's only using it about 45 minutes two or three times a day, at mealtime. Still, it serves it's purpose and is delightful to sit next to.

But I'd never consider heating a whole house with these things, as is suggested in the literature.

http://www.econo-heat.com/main.html

 

[Beno]

For sure the hydronic radiant floor gives the best confort, almost everybody says so and I agree. The question is though at what price. I too design a passive solar house, highly insulated etc, and using 6" blocks ICF. The house will have about 1800 sq.ft. on each of the 2 levels, with no basement. I'd like to use hydronic radiant in the slab on grade on the first floor (mainly ceramic tiles) and for the second floor I can decide later, after we move in. There will be no oil/gas heaters, but solar and electric. I also like the idea of hydronic floor where the water is heated by the solar radiation from the true south and heats also the north side of the floor.
I have few concerns though:
1. The price of the hydronic radiant floor (with PEX tubes in concrete, manifolds, installation, maintanance etc)
2. The efficiency of the solar in the long, cold and cloudy winters here in Ottawa, Canada (we have often here -13F). I've read contradictory opinions about how efficient are these solar panels in the winters, mainly when there are clouds or even worse, wet snow.
3. The price of the solar heaters. In my area, the price of 2 panels installed is around $6000 CDN, I wonder how much will be 8 panels?! I know in US there are very good incentives when you buy solar, but not around here (yet).
I also plan to heat mainly with wood, the Sequoia cat fireplace is supposed to give a huge pile of heat. I plan to make vents that connect the 2 floors, so the warm air can warm also the second floor.
Now for the infrared panels, they are attractive, but if you need to keep them ON all the time, it's expensive. In today's reality (which I believe will get worse in the future), I think is better to heat a thermal mass instead of air or people, using solar and wood as much as possible.

 

[Sandor]

Do those ceiling radiant heaters differ from this thing I picked up at the hardware store (see: photo)?

It is billed as a convection heater and the instructions insist it be mounted on a wall, with one inch clearance, to allow air to convect behind it. It's meant to set up a circular flow, but that assumes you mount it on a wall. I mounted mine on the kitchen island to allow me to lower my forced air NG furnace, and still not hear complaints at breakfast.

Mrs. Mo Heat and Mother Mo Heat occupy the island chairs. I can tell you, it not only convects, but it also radiates. Of course, sitting so close to this thing, it would be hard to not stay warm.

It is 110V and about 500Watts. If I left it on all the time, it would cost a fortune. Even with a kwh costing about 5.6 cents here (soon to go sky high BTW), I figure it adds about $15 per month to the electric bill, and that's only using it about 45 minutes two or three times a day, at mealtime. Still, it serves it's purpose and is delightful to sit next to.

But I'd never consider heating a whole house with these things, as is suggested in the literature.

http://www.econo-heat.com/main.html

Mo, I do not understand how that is costing you 15 bucks a month.

500 Watts * 3 hours = 1500 watt hours or 1.5 kwh per day.

1.5 Kwh * 30 (days)= 45Kwh.

Even if electric is 10 cent a Kwh, that is $4.50 a month.

 

[Mo Heat]

Mo, I do not understand how that is costing you 15 bucks a month.

500 Watts * 3 hours = 1500 watt hours or 1.5 kwh per day.

1.5 Kwh * 30 (days)= 45Kwh.

Even if electric is 10 cent a Kwh, that is $4.50 a month.

Good point. That's what I get for talking off the top of my head. Here's what really happens. We warm the thing up for Mother Mo Heat about 1/4 to 1/2 hour before she arrives (it takes at least 10 - 15 minutes to feel any heat at all and 15 - 25 to reach operating temp), and sometimes we eat in shifts, so usually the thing is on about 2 hrs per meal average, as we sometimes linger reading, clipping coupons, planning routine trips, etc.

Plus, Mother Mo Heat has some, let's call them, eccentric habits that change periodically and have something to do with her bowels. A common fixation as some of us age, it seems. :gulp: Anyway, we have what we refer to as Tomato Time around 10:30 pm here, so there's really 4 usage periods per day.

Add at least one day per month when we forget to turn the thing off over night, which adds about 12 hours usage per month. I've tried several timers, even some fairly expensive digital ones designed for resistive loads that far exceeded the heater, but they've all burned out in a few weeks, so now we just use the switch, and sometimes forget. So we generally have:

2 hrs x 4 times per day = ~ 8 hrs per day x 30 days per month = 240 hr per mth + 12 hrs unintended use equals about,

252 hrs / mth x 500 W = about 126 KWh / mth x .06 (and climbing) = ~ $7.50 per month. And I'd say that is worst case.

So you're right. I quoted twice my usage. Off the top of my head I automatically included an additional $7.50~ for a second space heater I placed into service at the same time as the panel heater. The second is a portable 1500 Watt baseboard electric heater that we added in Mother Mo Heat's TV room. It uses the other ~$7.50 / mth, maybe twice that much if it's cold and she isn't out running around so much during the day and thus running it more (it is thermostatically controlled, though, so it goes on and off by itself, for a grand total increase in electric, roughly speaking, my originally quoted $15.00 / mth. I think (top of my head memory) my electric bill may have even reached an additional $30 / month on occasion this last winter when the baseboard heater was in heavy use and it was colder outside.

Sorry for the bad data and thanks for pointing it out. Didn't mean to give the little heater a bad rap. We actually like it, but use it sparingly. Same with the baseboard heater (which is on a wall-switched outlet that had a very poor wiring connection. It was arcing pretty bad inside the switch and was smelling that interesting electrical burning smell before I figured out where it was coming from. Not sure if that would have started a fire, but it was disturbing. Changing out the defective light switch solved the problem.)

The benefits of using the "concrete, convection, wall heater" and the "1500 Watt portable baseboard heater" are that we get much improved localized space heat (higher air temps and close range radiation keep Mother Mo Heat toasty warm and happy) in small areas that provide greatly improved comfort at the kitchen island and in her TV room. And best of all, I can turn the forced air NG furnace down several degrees. It's hard to say how much NG we're saving, but I suspect it is at least a couple times the $15 increase in electricity. Maybe several times. With NG rate fluctuation and colder and warmer days from year to year, it's almost impossible to calculate, but I think we are saving and we actually feel warmer, especially downstairs with the wood insert blazing. :cheese:

 

[Rhone]

I know what you're saying, to answer some of these questions I'll start by saying it will certainly work in Ottawa, Ottawa is 3% less harsh by heating degree days than the place in VT but 150 miles north getting a bit less energy. The place in VT reports 206 days/year are full cloud, I find it hard to believe it that bad, Ottawa reports 163 days. The solar house was built to compensate with 8 panels instead of the 7 norm. 2x8 walls instead of the 2x6 norm. The Pex tubing running through the slab twice, the norm is once I think. A Gambrel instead of a less efficient colonial, it's engineered to take 1 day to charge and coast the next 2 days without sun, else it wouldn't work where it is. Wet snow isn't a problem, the angle of the panels slides off or melts as the panels warm up. The flat plate collectors do anyway, the evacuated tube panel types don't let heat escape so won't melt snow that accumulates (Flat plate collectors are superior anyway IMHO). The price of the solar panels isn't much of the cost when you consider how much it costs for 1 panel vs. 8. The cost of piping one, the special water heater, controller, etc. that's most of the work and significant part of the cost, the panels are $675 each and a piece of cake to install or add additional ones once you already have some in place as the hard part is already done.

Here it's $9,400 for parts ($10,058 CDN) for an 8 panel kit that should include everything needed but we get $2,000 credit here then subtract any individual state and city stuff. Somewhere starting at $7,400 in USA if you do it yourself (and that's 8 panels the norm is 7). I can't guess how much is installation, or how much "other" things will be if not doing it yourself. One may also need a crane, the panels each way 100+ lbs (50 kg) so not something one can bring up a ladder easily. Some states have good incentives others nothing. In Canada because of your health care taxes I believe that's a huge sum of money to you, whereas in America that really isn't a lot. Is it worth it, putting a $15,000 solar system into my 30 year mortgage on a new house will increase my mortgage $100/month and that takes care of my heating and hot water including a 10% fudge factor whereas instead opting to pay for wood & oil for heating and hot water I'll pay $120/month for it. So in the end it's cheaper to go solar and, honestly I'd rather not have to store 8 cords on my property, deal with the stacking, and the cost of it and oil is going way up each year at least with solar I'd have some kind of a buffer.

I'd actually mortgage a stove & solar for $20,000 increasing my mortgage $120/month and opt for the electric PV panel that drives the solar pump so the whole system is off the grid. But, that's just me and my opinion could be biased I'm just blown away with how well that Solar house in VT does, and it's been doing it since the early 80's and looks to have another decade or more. If you collect your wood and it's free it'll be cheaper until the point one pays more than the cost for fuel for their hot water and the cost of gas & maintenance of your chain saw and driving to get wood... which is probably some years. One neat thing about the radiant floor slab, todays have a valve that in summer directs the cold water to go through the slab before ending up at any faucets, showers, etc. Stops stagnation but more importantly watering the lawn, doing laundry, helps cool your house in summer by sending the cool water through the slab first helping you save $ from the AC. What's really neat is taking a hot shower or doing dishes, anything with hot water the incoming water first cools the slab down and the water gets pre-heated from energy from your house before entering the hot water tank so you double-dip in the savings using hot water in summer. Also prevents sweaty toilets. In the end, I think it's applicable in the USA but, in Canada you do have a good point that is a lot of CDN $ if I'm not mistaken.

 

[Beno]

Thanks for your detailed explanations. I agree with all you said. One question. I plan to have also a Gambrel roof, also for the look but mainly to save on the ICF walls and lower the total height of the house. You mentioned that Gambrel roofs are very energy efficient, and I wonder why? There is less room for insulations, I could put 1 foot of insulation in a gable roof, but not in a gambrel, where part of the roof is the loft kind of walls. Do you think that infrared panels are efficient with a taller gambrel roof?
Thanks again,
Beno

 

[Rhone]

The solar house in VT looks like http://www.mzhomes.com/assets/Closed/10Stoneg.jpg imagine 8 solar panels though. That's the Gambrel design that's more efficient than a colonial allowing few windows and allows extra insulation in the walls of the second floor. I know the type of Gambrel you're talking about, looks something like (broken link removed), which you're correct is hard to sneak more insulation.

I would use blown cellulose insulation in the attic and walls where possible, and offers high R-Values/inch and very cheap. But, it can't handle as high as temps as fiberglass, if the temps of the heating panels are not compatible with blown cellulose use fiberglass above the heating panels then blow cellulose over everything else. Are you saying you're going ICF for the first floor walls? Interesting choice. Just be careful with ICFs, there's a test performed on them where it "acted like an R-50 fiberglass wall" and everyone advertises that leaving off the part "not for long". They're R-21 and places that advertises R-50 often in fine print at the bottom of the page (dig deep) will inform you one should expect R21 performance from them. They are very air tight and buffer temperatures & sound with their mass, which increases energy savings over that of say an R-21 wood framed wall but, hard to compare them apples-apples when one has a mass the other does not. ICF's are also not the best walls, the best ones have the mass on the inside, insulation on the outside. They fall somewhere in the middle, better than wood framed walls, but not as good as the concrete ones with most of their insulation on the outside.

I can't say I've ever figured out the thinking behind their design. Heat wants to go where there's the biggest temperature difference, and it's loss or gain dependant on how easy it can get there through insulation. With ICFs, the energy stored has some difficulty getting out because of the 2" of insulation but it also has just as much difficulty getting inside with 2" insulation there as well. However, the outside is -20C the inside 20C so the energy is overwhelmingly going to be pulled to the outside and lost with ICFs. I have a feeling it may perform better to remove the 2" insulation on the inside of the house but, wouldn't dare. With 4" insulation on the outside and the mass on the inside of the house it has a tremendous amount of difficulty getting out, but has an extremely easy time staying in and will be a superior design especially for places with extended times of heat or cold.


I probably wouldn't worry too much about going higher with the roof. Insulation works by factors, the formula to tell you how much energy a particular R-Value will save you is 1-(0.5/R-Value) and the result is in %. So, for example R-1 cuts your heat loss 50%, R-2 would be 75% instead, R-4 = 87.5%, R-8 = 93.8%, R-16 = 96.9%, R-32 = 98.4%, R-64 = 99.2%, R-128 = 99.6%. As you can see, there's hardly any difference between R-32 vs. R-128. I personally try to aim for R-40 or more in the attic of todays houses with cellulose since it's so cheap but, I don't complain if I can only get R-16 in spots cause it's reducing 97% of the heat loss.

Just want to ask, you sure you want to go with these electric heating panels? Everyone I know that has electric heat moved over to a different system, they couldn't afford to keep up with the costs of using them. I'm hoping they're only for spot uses and you'll be using wood almost exclusively. Here, you use a gas/oil fired hot water tank today and skip the boiler to heat ones house and use radiant floor heating. Hot water tanks aren't as "efficient" as a boiler, but if you have your hot water tank also used to heat your house it performs double-duty eliminating one of the two standby losses making it more efficient than rated. I'm thinking since you'll be installing a hot water tank anyway, instead of paying for a tank, these panels, the wiring, switches, and electricity to run them each month instead get some PEX tubing and hook up a hydronic heating system hooked into your oil/gas hot water tank, it may be comparible in price but probably less $ to run. You could even use staple-up radiant floor heating for the second floor. Unless electricity is extremely cheap where you are.