How to Install Radiant Heat Ceilings | This Old House

Radiant heat goes in somewhere unexpected: the ceiling!
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The Cape Ann mudroom has lots of windows and there is not enough floor space to allow the radiant panels to provide enough heat. Richard Trethewey finds Kevin Bilo installing radiant in the ceiling.
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How to Install Radiant Heat Ceilings | This Old House
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[@I-Teee]

All these years, it was an air hammer in my wife’s nightstand. The more you know. Thanks TOH!

[@messanatech]

Great video! Another option is our radiant ceiling panels which are quite a bit easier to install! We can even provide BOTH radiant heating and radiant cooling!

[@DuramaxL5P]

That little air powered hammer made a very amusing noise!

[@rickywalker5523]

Li 9y0 has said

[@rabbitslayer42]

Doesn't warm air rise, what's the point of heating the ceiling ?

[@bencatanzaro]

The metal backer plate and the insulation they put behind it should drive the heat down.

[@x2thel]

It's RADIANT, the sun is in the sky yet we get baked in Arizona.

[@daviddesilva4971]

With the return air in the ceiling it will always be cold in the winter months.

[@sgtcrab2569]

Ok in Arizona...not so much in North Dakota.

[@rabbitslayer42]

@@x2thel But the heat from radiant heating only heats the air around it, unlike the IR rays shooting down at us from from above in AZ

[@davidsearles1701]

brand name of the product??

[@tinysand3517]

How do you service radiant heat ceiling? Like add a recess light or dry-waller put a hole by accident....

[@demagab]

You gotta remember you have hot water pipes in your ceiling

[@scallywag1716]

Homeowner decides to mount new light fixtures...drill through PEX line. Whoops!

[@Kaliburz]

That is when they have to know their home.... now... if it gets sold & a new owner does it... all bets are off

[@IAmKyleBrown]

@scallywag I was thinking the same thing. @@Kaliburz All homes get sold eventually!

[@scallywag1716]

Ok, how do you know there’s PEX water lines in a ceiling? I’ve never had that come up in conversion when buying a home. It is one of those things that isn’t done...and a few good reasons. But I degrees...if homeowner approved it then that’s fine, whatever.

[@scotttovey]

@@scallywag1716 "Ok, how do you know there’s PEX water lines in a ceiling? I’ve never had that come up in conversion when buying a home. It is one of those things that isn’t done...and a few good reasons." This falls under pertinent information in real estate law. This being pertinent information, the seller is required to inform the buyer of the location of all radiant heating pipes that are not obvious.

[@twbrkfd1733]

@@scotttovey Lots of pictures before putting up drywall to record locations of PEX.

[@ekjswim]

Is that a _corded_ powered caulk gun? Never seen that before, pretty slick.

[@ekjswim]

Air powered! Even more odd to a diyer. Glad I asked. Thanks!

[@donovanjones4175]

Can this be used to heat the space above, say a second floor, without having to tear apart the 2nd floor?

[@lukerose5190]

No because there is 12 inch joists between which the heat would be dispersed throughout the whole house

[@kubtastic]

I'm sure the homeowner did not *want* a radiant ceiling, but wanted to pass inspection and this was a solution. The nice thing with radiant is that it makes zoning very easy so the energy savvy person can let this room be a tad cooler.

[@IAmKyleBrown]

Couldn't you still install the heat under the cabinets with some venting in the toe kick? Also, of all the rooms in my house, the hallway to the outside/garage is the last place I care about heat. Hell, I actually prefer a colder mud room entry when coming in from freezing winter day.

[@IAmKyleBrown]

@Erald M. That makes a lot of sense, thank you!

[@harveypost7799]

Gosh I remember that trip to Canada when 10 years old ,the family .the asbestos capital of the world..even snowmen made from asbestos...

[@MasterChief-sl9ro]

Wait till someone drills a 4" hole for their new light....

[@BendeVette]

Isn't that always the case? You can not just drill holes in a floor or ceiling without first checking what's above (or below).

[@scotttovey]

@@BendeVette You know that and I know that. But the inexperienced do not know that.

[@scotttovey]

@@BendeVette In fact, the inexperienced may very likely respond saying: OK boomer! They like to dismiss everything that their elders have learned.

[@enigma7ic]

Scott Tovey Sometimes you gotta let the kids touch the hot stove

[@scotttovey]

@@enigma7ic If it was just the hot stove it would not be such a broad problem. They unfortunately, have been deceived into thinking that there is no long standing tradition of improving our nation. Just get rid of the whole system and start over. They want to be the founders of a nation without having the character, values and intelligence that the founders of these United States of America had. Throwing the baby out with the bath water, has rarely been a good idea.

[@ericwotton2046]

Up Next how to install a lit-floor!!

[@jblyon2]

Don't forget some windows on interior walls

[@pasqualeparente9776]

My only comment as a handyman is that renovation will require expensive thermal cameras to detect heating coils or heating tubes.

[@Justaguy0420]

I’ve got an app on my phone for thermal imaging....

[@akpartili5601]

HawaiianBryson that isnt a real thermal camer. It only highlights the very light areas as red and the dark ones as blue.

[@Justaguy0420]

AKPartili It came with a device that says “thermal camera” on it. It plugs into the lighting port on my iPhone. But I guess you are right. It’s all fake news. Covid 19s a hoax.

[@Comrade_YG]

Yay its nice to see richard

[@c.n.h4841]

I hope someone put that on the blueprints cuz 20 years late remodel could have a big issue. I'm just saying it's not a common practice to see it in the ceiling. I'm just hoping no one ends up tagging a water line down the road. I would hate to see someone remodel end of hitting one of those lines with something. Some people don't pay attention. I know for a fact on the west coast is not a common practice at all to place water heating lines of that nature in the ceilings.

[@GeeTheBuilder]

Kevin yeah that’s really gonna help when someone drills in to the ceiling to fit some lighting or whatever. This is such an idiotic idea. Insulate better and/or beef up the BTU on the floor.

[@GeeTheBuilder]

Erald M. What??? So when some homeowner drills in to the ceiling in the future to hang something and hits a pipe and floods the room, the response will be “well, it was in the plans....”

[@Davey768]

@@GeeTheBuilder ...yes? If you're gonna drill a hole somewhere, you have to check if anything's behind where you're drilling.

[@GeeTheBuilder]

Kevin why would an electrician fitting, for example, new lights go look at the ufh/ich (ich, in ceiling heating??) on the manifold?

[@c.n.h4841]

@@Kevin-mp5of I'm just stating that due to people not thinking it's not normal for a ceiling to have pipes Cooling or Heating most people won't walk into the mechanical room I just don't want to see a dingus drive to screw right through those pipes come on brother you know people are always The Brightest Bulb in the Box

[@spencerwilton5831]

If such a small space requires 5000 BTU which is about 1.5kw you have bigger problems than how to provide the heat required! All you're doing is heating the garden by the sounds of things. Need a better glazing / door system for a start.

[@Mom-tk9rz]

My mother in law just moved into a condo with radiant heat in the ceiling! She is retired & just moved in and turned it on and now nothing but problems! our eyes burn and her chest hurts. Environmental issue only when heat turned on or what?! No one else has a clue why this would cause this. Doesn’t bother some people but others it does. She is thinking to switch to Hydronic electric baseboard. Cant live with this. Anyone else know about this issue?

[@AlanPeery]

I would look for a chemical vapour issue from glue used connecting panelling to the ceiling joists.

[@gussieownby83]

We have radiant ceiling heat in our 1962-era house, and it works beautifully. It is not as efficient as our new heat pump, but it acts as a great supplement.

[@AC-tz3pk]

What is the size of that pex tubing?

[@eaglevision993]

Whatever it is, way too small for a well designed radiant heating system. Never go below 16mm if you can.

[@eaglevision993]

Hey there America, greetings from Europe. Nice to see you are starting to take radiant heating serious. But it is still very inefficient the way you do it. Wood does not conduct heat well, in fact it is a great insulation material. And the gap between the pipes is way to large. Install it in screed at a gap of 2-3 inches and you don´t need the additional ceiling heat. Overhere, we actually calculate the heat for every room and adjust the gap accordingly. So you can run the same temperature in your loops and still have a warmer bathroom and a colder bedroom.

[@eddygoodwin7089]

We aren’t all this dumb, Richard is cringing doing this you can tell he wants no part of it.

[@guytech7310]

Looks like the panels have an alum heat spreader. Wood has a low R rating or R1, and since Radiant is a low temperature heating system the wood isn't a real problem.

[@timesofrefreshing7966]

Wait radiant heat ceilings....this is a new idea

[@alec4672]

They used to do it with electric in the plaster in the 50s actually.

[@cup_and_cone]

1:59 Dude just exhausting aluminum shavings onto the new window. Nice.

[@bedlamp9157]

Nice catch

[@saulgoodman2018]

Those can't put out that much heat. Why not just put in a heat register. This just seems like a waste of money.

[@t1n4444]

Have a Google at your US radiant heaters industry websites. Pretty interesting stuff in a sort of "Mythbusters" presentationy way.

[@portaadonai]

Radiant heat must be great for basketball players, but I thought radiant heat was terrible, such a waste of energy heating the ceiling/attic instead of the bottom half of the room where you spend your time.

[@Justaguy0420]

It’s actually one of the most efficient ways of heating. Most people will install this in a concrete slab which would make your 6 inch slab a thermal mass that would probably last all night before your boiler kicked back on. I’ll be heating my radian system with a wood burning fireplace. Pretty much unlimited free heating.

[@portaadonai]

@@Justaguy0420 this is a ceiling install

[@eddygoodwin7089]

@@Justaguy0420 yes not a slab on the ceiling

[@MrGelowe]

What was that thermal paste?

[@MyKonaRC]

@@Kevin-mp5of A.K.A thermal paste

[@zack9912000]

not the correct way to fix this issue

[@ridgewoodgardens6253]

Your solution?

[@David.....]

Radiant heat, radiates energy in all directions...They already said they did not have anymore fllor space to get more surface area to increase btus... since the radiant heating they are using is hydronic, it is already the most energy effiecient (70%) design transfer the heat to this area. What is wasteful 70% of homes in the US with forced hot air thats basically 25% efficient....

[@Engineer9736]

Ridgewood Gardens If someone wouldn’t know a correct solution doesn’t mean that his statement that this is not the correct way would be false. And there are tons of heating methods. I’m sure there is one which does the trick without heating the ceiling space.

[@BendeVette]

@@Engineer9736 The correct solution would be a spacing of 4" in stead of 10". Not possible with this system, but very common in poured floors. Furthermore, laying the tubes like this gives an uneven temperature across the floor. Better to do a spiral (which is also impossible with this system).

[@zack9912000]

@@ridgewoodgardens6253 They picked the wrong system for that entry way. Since they want to use a hot water boiler to heat the home, in areas like that they could use a standard fin and tube radiant that would easly be large enough for the BUSH required. Owners as usual have unrealistic expectations and contractor get inventive to try a appease them

[@FreekHoekstra]

So you realize your room is an energy pig, and instead of picking doors with double glass to keep it reasonable, or make the hallway a tiny bit cooler, nah we’re gonna heat the outdoors by installing more heating sigh....

[@David.....]

The doors were double glazed....even double glazed units has a horrible u/r factor....its glass coatings that improve the decrease in solar gain against summer months....glass is always cold in the winter..... I've designed a lot of IGUs and since you only heat for 3-4 months of the year vs cooling 6-9, designers consider heat gain more than heat loss.

[@BendeVette]

@@David..... I would go for triple glass windows/doors. And heat is not a problem with the right coating/film on the outside. Keeps 80% of the heat outside. Another consideration would be, when it's hot, the sun shines and solar panels can power the airco. While in winter, solar panels do almost nothing, but the triple glass does. So almost free cooling in the summer and "no" energy loss in the winter is the way to go.

[@David.....]

@@BendeVette I know about solar heat gain and coatings... I design IGUs. Thats why I mentioned it....But you obviouly dont understand that there is definitely heat loss in glass panes in the winter....Triple pane windows are only 10% better than double pane residential grade ( off the shelf) at 35% more cost fyi.... Honestly it is not the windows that is the weak point.... its the air gaps around prehung windows, poor installation technique by 80% of contractors, and the use of fiberglass batt insulation. As they mentioned, they calculated the heat loss due to the wall construction, and shear amout of glazed surface sq ft. Doesnt matter if they used triple pane windows or not, the space needed around 5k btus per hour heating... which is not a lot. A 12ft run of hydronic baseboard would have put that out.

[@BendeVette]

​@@David..... I am afraid you got your numbers wrong. Triple glass panels are 50% more efficient with a 20% price raise. So they make sense in an very hot and very cold climate. Who is talking about air gaps? It is more than obvious, in a new build and renovation, that you make the house as air tight as possible with controlled ventilation, for instance with a ERV (with a normal or enthalpy exchanger) if possible.

[@rupe53]

@@David..... ... if you think about the construction that wall of glass doesn't have much room left for insulation and will be 90% 2x4 wood, which isn't that much different than glass when it comes to thermal transmission. Yeah, they can gain something using an insulated Zip-wall on the outside, but that's not really a whole lot in the big picture of that hall.

[@TheGenuineRannix]

Why is it code to heat the environement? The f?

[@786otto]

Not to impressed with it

[@johnlebzelter4208]

Ha. Who cares?

[@b_uppy]

Not half as good as radiant heat floors.

[@David.....]

You obviously didn't pay attention. They added radiant heat to the floors, but the sq footage was insuffient to heat the space per thermal load calculations... To get to the correct btu per hour, they added the ceiling surface in addition to the floors.

[@BendeVette]

@@David..... They should have decreased the spacing between the tubes to 4". But than this product wouldn't be adequate, and since they sponsor ......

[@David.....]

@@BendeVette its a predesigned system with a predesign radius to prevent damage to the pex tube....yes increasing density would be nice, but altering a ul approved system is not allowed. They could have chose another system, but I assume they choose the best system based on needs of the whole house, cost, heating system type.....its better that they used same system everywhere in the house.

[@BendeVette]

@@David..... I am afraid they used the best product this sponsor could deliver. But unfortunately it is a poor choice as this ceiling heating should be totally unnecessary.

[@b_uppy]

@@David..... I did pay attention. Heat rises. Who needs a hot head???

[@Dial8Transmition]

Need more nails

[@Mermaidlife97]

Why would you install this junk? I have it due to landlord who refuses to even have it looked at and I freeze all winter and my bills are outrageous! I can only keep it on at 55 in two rooms and my bills are SO high. What a waste of talent

[@bradm1627]

As a hvac tech in Canada this is very wrong and a waste of money not how you address this problem! What a waste of money!

[@t1n4444]

Hmm, in actual fact you are not quite correct. If you were to research the physics of radiant heat, from above, you might be amazed at how efficient such a system is. Even more amazing is that ceiling heaters have been around for over a hundred years. Radiant heat doesn't warm the air as such, it warms "you", hence my suggestion to Google up the details as the physics takes a bit of explaining. It involves heating by infra red radiation. Please note that the radiant heating doesn't involve things like air changes or air circulation. Plus has nothing to do with hot air rising or anything similar. If full on research isn't your thing then there is an article on radiant heating from the US Office of Energy Efficiency and Renewable Energy in Washington. It's written in a fairly dry style and avoids the "bigging up" of such a system as would a manufacturer, say. IE, they aren't try to flog you a system but merely describing the way it works. Interestingly the article does touch on the cons of a water heated system because of possible leaks. Plus it does mention that whilst electric systems are almost 100% efficient does it not imply they are cheap to run. Hope that helps.

[@felipepubillones2768]

This just seems like a horrible idea. If that area is not heating enough, you have poor insulation, HVAC, and doors/windows. I can't imagine that for the amount of electricity that'll eventually use, you'll get meaningful heating. Especially when the floor already is. As many people mentioned, heat rises. There's enough holes there to cause a heat escape. Also, sheetrock alone is somewhat of an insulator (at very least piss poor conductor). You'll warm up the ceiling alright, but not the room...at least not by much. Unless there's some sort of blower forcing the warmed air down, it'll be mostly lost. And to echo others, all you need is one errant screw to destroy it completely. Overall horrendous idea. There's a reason you heat the floor with this concept.

[@David.....]

Radiant heat is not meant to heat the air, it heats the building materials and you thru radiation. You spent to much time in a forced hot air space, relying on vents and fans to thermal balance the air temp.... Remember 100 years ago how steel radiator worked...no fans, no electricity, just steam, and radiant heat that travels in all directions.

[@felipepubillones2768]

@@David.....you really want me to believe tiny tubes with hot water will get hot enough to radiate through sheetrock and then heat up the air with any amount of efficiency? If you understand the basics about different forms of energy radiation, radiant heat needs a more direct contact. This is so buried that it's inefficient. That's why even the floor version is just a supplemental to central heating. A radiator only gives radiant heat to the air around it or if you stand literally next to it. The heat you feel in the room from that old school radiator is through convection, not radiant. So again, horrible waste of money.

[@kidalwys]

@@felipepubillones2768 this will be great we install it all the time. Then for people who don't want to shovel we do snowmelt also.

[@David.....]

@@felipepubillones2768 One, there is a aluminum reflector in the track system to reflect radiant energy into the room, from the floor up, or the ceiling down... Two, sheet rock is not a great insulator...thats why we add insulation in walls/ ceiling/ floors and why they added extra insulation and reflective material to the ceiling above the radiant track boards... Remember that there are different types of sheetrock. An example is a 1 hour fire rate wall, have 2 layers of type X sheetrock with 2x6 studs and batt insulation. Sheetrock itself has a r value of 0.5. Yes heated AIR travels up, but they are trying to heat the building structure/materials. Heat/conditioning doesnt need to be fast, Just consistent, and comfortable. Three, heating air and moving it is inefficient....Thats my every other country on the planet with high energy cost already use heating tech like radiant heat, solar exchangers, geothermal, air ventalation heat exchangers, heatpumps (with ductless mini splits popular), hydronic....look at how heating is done in switzlerland, germany, finland, sweden, greenland, south korea, estonia and more

[@BendeVette]

@@David..... Better go with a denser layout at the floor. The spacing of those tubes is too wide. A distance of 4" (10cm) would be much better (which seems to be impossible with this system.

[@redneckgoatfarmer]

Ugh, stop with the radiant heat crap. Anybody thinking about getting this crap beware of days that start cold and then warm up, because your room will take hours to cool down. Your AC has to kick on to compensate.

[@marcz9482]

It's 2020 this old house is taking people for sucks too now. Heated ceiling? Heat rises, get out here with that bs.

[@ModernGentleman]

A heated ceiling is the dumbest thing I've ever seen. Heat rises.

[@t1n4444]

Research for you my lad 😂. US has been using heated ceilings for over 100 years. In fact "you" are very good at it. And "heat" is not "heat" per se, it is IR radiation. It's been around for past 13.4 billion years and hasn't failed yet.

[@rounakchatterjee299]

Convective heat transfer rises upward. You obviously don't know how radiation works.

[@eddygoodwin7089]

This was dumb in the 70s and it’s dumb now come on Richard I know you don’t want any part of this garbage.

[@t1n4444]

Eddy Goodwin. Indeed the idea is not at all dumb. Heated ceilings first used in US over a hundred years ago and highly regarded (no pun intended btw). Radiant heaters used extensively now through US on both walls and ceilings. Technically they are far more efficient than radiators, in or those floor pipes with radiator fins or underfloor heating matrix kit. Might be worth a Google to see how radiant heaters evolve by appliance of science. Radiation in this instance is infra red.

[@eddygoodwin7089]

@@t1n4444 I know that heat rises

[@t1n4444]

@@eddygoodwin7089 Well quite, but we aren't talking about heating units that causes heat to rise. The technology presented is that the radiant heat is "projected" down. It's not about heating the air at all. The "heat" doesn't exist until the radiation reaches your physical person. It might help to have a squint at one of the companies who build such systems in your area. Once you have got through the advertising the principle will be explained for putative buyers to understand what they are buying.

[@eddygoodwin7089]

@@t1n4444 I have installed radiant heat in floors and understand fully how it works. radiant heat works fine but when it is blocked by sheet rock that is a barrier that will cause heat absorption. I think most professionals would agree that it better in the floor for several reasons.

[@t1n4444]

@@eddygoodwin7089 Well, you might suppose that underfloor heating was more efficient but in fact no. Radiant heat panels in ceiling most efficient, then panels in walls come second, then the floor. Please note we are talking radiant heat, not systems to heat the air, then "you", which are regarded as not very efficient. I have to say that this radiant heat topic is more interesting than I had expected so had a look around internet for your actual mostly non commercial appraisals by "technical or scientific" type bodies. The science is a bit wordy to reproduce here so if anyone is up for it then might I point you towards: ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) Or: NAHB Research Centre. (National Association of Home Builders) Or: Resilience.Org Or: itsolution.lindab.com Or: GREEN BUILDING ADVISOR.com Or: LOW TECH MAGAZINE.com (Science Alert) Be advised up front there is a "lot of science" in the above and quite a few references to many, many other scientific papers dating back to the mid eighties to date. These are found, mainly, in the bibliography sections. The main thrust is how the IR radiation "works" on a person's physical entity. Said papers relate also to the thermal efficiency of a structure but don't dwell on how houses or buildings are constructed in detail. Sort of how a building "works", not how it is made. (Although building techniques are covered elsewhere on some of said sites.) So, if you have a week or three spare during lockdown then something to keep you occupied ...

[@ronringwald5120]

DO NOT INSTALL RADIANT HEAT UNLESS YOU LIVE WHERE THERE IS NO WINTER, radiant heat sucks worse than having no heat at all, i have radiant heat way up here in Northern wisconsin & i wish I could throw it out forever, my wife & myself freeze every day during the winter, we had to take a loan out to install a wood fireplace to heat our 2 story home. DO NOT BUY RADIANT HEAT, save yourself the anguish & pain of having a dinosaur era heat system that didnt work then & it still doesn't work to this day.

[@SgtZima]

Ron Ringwald It sounds like you got a crappy install, a lot of modern homes are moving to radiant floor heating.

[@ronringwald5120]

@@SgtZima maybe in the south, not up north where we have real winters, radiant is a waste of time & no my system is only a few years old, so its not bad system, the bad system is radiant heat, get it right, when temps drop down to -30 / -50 below without wind chill, radiant heat does not even compare on any lists to forced air or wood heat.

[@David.....]

Well i have radiant heat in Ct, and my coworkers in pa, and wisconsin all love it. Saves money is super efficent....Just got to make sure its designed correctly, installed correctly, and most importantly that the thermal loads calculated correctly... You know that there are 100s of type of radiant heating systems on the market, with hydronic pex based being the most common. Pex is 30 year old tech. Hydronic heating is 100 year old tech, radiant heating 150 year old tech. Think about it....remember those steel radiators in lots of old buildings. Wood fire place heating is the most ineffiecent type of heat source unless you add a stove or use a WOOD PELLET based system.

[@kidalwys]

You must have a bad install. We do a ton radiant heating with pex and snow melt. Even businesses are going with it.

[@ronringwald5120]

@@kidalwys nope, great install, poor way to heat anything, Fred Flintstone wouldn't use radiant heat, takes way to long to heat, uses up heat source way to fast causing huge heat bills, GET WITH THE TIMES, its not 1850 anymore, its 2020, are you a repersentive of the fuel company with kick backs, radiant heat should be banned do to costs to have & use it, very not cost effective at all. Wood heat or forced air is the only way to go to have heat NOW NOT LATER .

[@tkjazzer]

What do anti-plastic millennials use instead?

[@guytech7310]

live in Mom's Basement. No need to worry about stuff like plastic.

[@tkjazzer]

@@guytech7310 buy a immediate read Radon Detector if you live in the basement.