My Dad did this in the 1960s with a self-made system that pumped "ground" cooled fluid, not water, but water and antifreeze, through our radiators. It came in at around 50-60 degrees F, good enough to cool the house down to 75-80 on the hottest summer days. The radiators sweat. but that was easy to clean up if it meant a cool house to Mom. The water pipe system ran underground into a cavern pond near the house that always stayed cool where it radiated the heat. He developed the idea from his Dad who owned an old west saloon where they kept beer cold by storing the beer barrels in an underground dugout cellar.and piping the beer up to the tap. If they could get ice from an ice house, then the ice would be placed onto the kegs to help. I'm still using it, and right now today was 110 degrees and inside it was 85.
@@AnhNguyen-ul6lb just turn off the pump and the water in the radiator won't be moved to the heat sink (in this case, a lake), and therefore the radiators will be the same temperature as the air in the room. all you'd need to do is connect the pump to a thermostat and it would shut off automatically.
@@kimie126 an electronic water pump that circulates the water (just the pump, no heat exchanger or anything else ) would consume about 200watts. an 12.000btu a/c would consume about 2000 watts, so 10 times difference in electricity costs
Please, please do more on radiant cooling. It’s a technology hardly spoke of, but seems to have some advantage. I’m trying to do research, but not a ton out there, definitely not much on you tube.
The reason it's not getting wet with condensation is NOT because you have a dehumidifier. It's because the temperature of the cooling panels is above the dew point. If you take a glass of water out of the fridge it gets wet but if you take a bottle from your wine cellar into the house it won't, because it's just not cold enough. Same principle here. You need a larger surface area with the lower temperature difference though, hence the large ceiling panels. If you're in a mild temperate climate like Canada, northern USA, Europe or New Zealand, you could run this without a dehumidifier.
Humidity and Temperature both contribute to dew point, it's not an issue of one or the other; both must be managed for a system to be successful. Maybe it would be fine in Canada and New Zealand, but it only take a homeowner that enjoys more humidity than the system can handle to cause a failure. Better to have the dehumidifier and not need it most of the time, than need it and not have it all of the time.
I'm doing sort of the same thing. More geothermal though. Ground water temp in Northern michigan where I am is roughly 42 to 47 degrees during the summer months and I just pump that to coils in the furnace and use the furnace to distribute the cold air. uninsulated I get 62 degree temps from the vents. I am only pumping 1 gpm of ground water through the system with about 180k btu of coils. Cost to keep the house 74 in the summer was about $25 per month figuring the electric for the Furnace, water pump and control solenoids. Cheap. I also ran a dehumidifier to control moisture levels.
This may be a first for residential, but I work in commercial HVAC and have seen many similar systems with chilled ceilings and chilled slab floors. Good controls are critical to ensure the no condensation occurs on the system.
I thought of this before myself just laying in bed at night. Nice to see it in operation. Personally I don't see it being popular in homes but my hats off to y'all for the engineering work.
Back in 2011 went to the porsche museum in Stuttgart Germany with a family friend, that night her BF said that one of his design projects for the company he worked for designed the "radiant" cooling panels in the ceiling on the museum and pulled out a sample from under his desk. It looked similar to this system, only the Pipe was raised on an inverted aluminum T. At the time the company he worked for had installed quite a few of those systems in large building throughout Germany and europe. So the commercial application of this tech has been in use for quite some time in Europe.
I had a similar system installed. It is very comfortable. When the air is moist however, you need to adjust the water temperature using a mixing valve to avoid condensation. This in turn lowers the cooling capacity and you need some fancoils as a backup for those hot and moist days. The fancoils can make use of the same water chiller unit used for the ceiling. The control circuit has to react correctly to changes in temperature and humidity. This kind of system is very comfortable, but quite expensive.
This is next level heating pad cooling for maximum energy efficiency. Seen this in a Chinese scyscraper and had to Google to see if it available for home in the US. Thanks for the info
I do the same thing on a small scale with my computer in the winter. It is water cooled, but I live in Colorado and it gets to like negative 20 in the winter. Rather than pump additional heat under my desk, I run the water lines to a huge radiator I have outside. It is almost completely silent, and actually functions better than my normal water cooling in the summer.
Joseph, I watched the video again and I cannot find anywhere that either of them say this eliminates the need for ceiling fans. Risinger was simply stating that the space they currently occupy has no fans on and yet it is still comfortable. You can choose not to believe him, but let's be accurate when discussing what was said.
When we build our house in North MS in the next two years, we are going with double stud wall framing and 12 inches of dense pack cellulose along with a Canadian window company's tilt and turn triple glazed windows and hydronic heating and cooling in the slab and ceiling panels like these. Great job on promoting awareness guys!
@@pennguino9137 Hi, Thanks for the question! We actually looked into ICF construction, but with the huge amount of energy needed to produce concrete, we decided that wood framing was the better choice for us as far as minimizing resources needed for our home. Plus the foam insulation is fairly toxic and nearly impossible to recycle once it is at the end of it's life.
If you have to run a dehumidifier with this setup, you might as well use a small AC unit instead so the latent heat is moved outside instead of being returned to the room. Regular central A/C is probably more efficient than this when you consider energy use for dehumidification.
Depends on the climate. If you're in Florida or northern Australia then yes, you need to dehumidify to be comfortable in summer. If you're in Canada or Europe you could definitely cool the house enough with just a reduction in sensible heat. Here in Brisbane, Australia I ran a simulation on my house (I'm a thermal engineer) and found that the summer cooling load is 50% latent and the "hot winter day" cooling load is 100% sensible. So in places like Vancouver where the summer is equivalent to our winter, you don't need to dehumidify.
while this might be more efficient than standard AC, I think we can make it better. rather than using a chiller to cool the water, which would require a decent amount of electricity to operate, what if we hooked these radiators into a geothermal loop? If we're using the cool temperatures of the dirt deep underground to cool the water, all we would need to operate is a pump to move water through the loop. it would be much cheaper to operate and much better for the environment than any cooling system we have on the market currently, and it would get the water down to about the same temperature, if not a bit cooler, than the chiller he has the radiators connected to.
My personal favourite is a combination of many. Isolate your houses quite well. Build fans that can exchange the whole air in the house throught the night multiple times (To get the free cooled air outside (if its cold enough)) Groundcooling is a very nice solution which can cool stuff down to 12 to 15°C (at a depth of >2m). But with an extensive use in the summer, the earth will heat up and the effect reduces itself. But the heated earth can be reused at the winter for heating purpose :D. When there is still the las "bit" missing, use a small air condition unit which is powered by solar. You need the cooling most the time when the sun is high up, so perfect use case. My company is cooling down the whole building complex with a similiar approach to groundcooling. Except that they are using the water of a nearby river. It helps to lower the temperature by round about 8 degrees in summer, combined with dehumidification devices it feels good enough.
I've installed too many geothermal system down south - gave nothing but headaches.With geothermal you are only saving the electricity from the fan motor - minus the lower consumption water pump. Savings are negligible. Not worth the heart ache and expense of the installation. The best way is to install a bullet proof, tried and true A/C, w/no efficiency gimmicks. Then add 5000 watts of solar grid tie power to your system($3000 panels + $1500 grid tie inverter) . No batteries, and not even tied to your home. Its tied directly to the grid causing your meter to spin backwards. That's how you get a good, trouble free, high efficient A/C system. Note: Solar panels have almost ZERO maintenance. Ok, you should clean them every once in a while. Hose the dust off. FYI- That system would cut your A/C electrical usage by more than 50%. Take a 14 SEER, now its a 28. ;) And if you add enough panels you could completely off set your A/C usage. At 10,000 watts X 6 hours = 60KWh produced vs 3 ton A/C (3000 watts) X 12 hours (run time) = 36KWh consumed. Net gain of 24KWh of electricity. Probably enough to offset your entire bill. 10,000 watts panels = $5000 (only $2500 if you buy at auction), or $10,000 if you don't shop around. 200 AMp Grid tie Inverter = $1500 plus labor.
@@2pi628 I don't mean to connect them to a geothermal heat exchanger, I mean literally just have water running through underground pipes directly into these radiators and then back out into the underground pipes as a means to cool the radiators.
This is an interesting idea. I would think it would be more cost effective as the cooled space got bigger and the humidity wouldn't be as much of a problem in dry areas like AZ and NV. both places that need a ton of cooling. I also like the thought of not having a bunch of leaky air ducts that draw in dirt and blow it all over the house, a bad part of life in a desert. Having to run a dehumidifier during monsoon season would be a tiny price to pay in order to get rid of the dirt on everything. I'll keep an eye on this tech.
Glad to see this old technology making a comeback with PEX piping and dehumidifiers. I had a radiant heat book from the 1940's that showed ceiling and wall cooling with steel piping and block walls. Cool surfaces will condense water vapor if relative humidity is not controlled. Nice touch.
True, a system like this won't be able to condense the humidity out, my concern would be a desire for an air cleaner as well. I'd say if you're in aa humid climate, just supplement this with an air handler that's got an A coil in it, run air through it. it might not be enough to cool the entire space (the air handler) but if sized properly it could solve the humidity problem while still contributing to the cooling.
I think the solution there is combining this kind of thing with a high velocity small duct system. I know not everyone does, but personally, with my allergy issues, I want the air constantly being replaced with purified air.
One simple point. Glycol cooling with a chiller. My college uses chillers with their heat exchangers built back in 1950's to keep the buildings cool during the summer. They have been converting from central steam to localized boilers to heat the buildings. Also I'm in HVAC classes and just took a tour of the facilities so get a better understanding of how the school is built.
I was just in a house where the homeowners recently added a chiller to their radiant in floor heating system. The husband is in the hydronic and steam heating business, so he knew about this. I was intrigued and asked him a ton of questions about this. I love good cold AC feel, so when I asked how cold it got, and basically they said it’ll easily make you uncomfortably cold, and the best results come when used with a ceiling fan. I think I’m completely sold. I’ll still want some sort of ducted HVAC system to control the humidity and filter the air, but it seems the best actual comfort control is radiant heating and cooling. I looked it up online and in most other parts of the world, this kind of thing has already become the preferred system in commercial buildings, and I think this is how AC will be. Having heard how great it is from someone who’s done this in their house for several years sold me!
I’m not sure about Texas, but up here in MN electricity is about 3-4 times more expensive than natural gas. I would be interested in seeing the data using a natural gas absorption heat pump
I remember seeing a system years ago which used radiators which had troughs and condensate drains underneath. Personally, I'm happy with forced ducted air.
I went to North Penn High School in Lansdale PA and that building, built in 1970 or so,did this same heating/cooling system with radiant panels in the ceiling and it was a complete disaster. The ceiling would sweat so much in the summer that it would literally rain in the downstairs classrooms. I remember taking a quiz and having to repeatedly wipe the desk with a gym towel to have a dry area to place the paper. Plus all the moisture made the panels rust and spring leaks. In the winter the building was abysmally cold, with all the heat stuck up in the ceiling. I think in the late 90’s the district spent millions fixing the problems.
Matt like your show. Just an idea for this application. We do residential and commercial buildings and use fan coil units with boilers and chillers. These can be put into a wall behind sheet rock, don't need dehumidifier, but need to drain condensation somewhere. System still involves a fan so not as comfortable but don't need to control humidity.
Pretty slick system I wondered about this with a GC I worked with 12 years ago and his response was "condensation". I have the only geo Thermal heat pump in the the small city in FL where I live. When I dropped my house plans at the building department for my addition and remodel they were dumbfounded. I only wish the engineer that designed my system had a clue so I could get all of the potential out of the ground source.
So glad there is a youtube channel for dedicated construction science nerds. Matt Risinger, you make what could be a boring topic into something super interesting. Also great editing, very pro. I'm a new subscriber going on about 3 or 4 weeks now and I've seen well over 50 of your videos now!
I just installed a radiant cooling system in a new home we built, the water is cooled by underground water lines buried in the ground below the water level, we have 1/2” pex on 8” center between the Sheetrock and insulation. The ceiling is at 72 degrees, it was 94 degrees out side today, inside it didn’t get any hotter than 73. First day running. No condensation, we live in a dry climate.
My worry would be maintenance and/or repair. That looks like plastic tubing in the ceiling plates, and all plastic degrades over time. Houses settle and shift. What would be the time and expense in repairing a faulty connection between ceiling plates? Could it be repaired by removing just one plate, or would the entire assembly have to be removed? My first thought was... Ah, Texas. I could see someone accidentally putting a bullet hole through a tile while cleaning a firearm. lol.
As a retired General Contractor, I enjoy the hell out of your Vids. One complaint; Why the hell does the volume have to vary so much. ??? I'm constantly jumping up to turn the volume UP or DOWN. AND, at 78 years old with Cancer, Jumping ain't so much fun any more. Jim L. North Hollywood, CA.
+epicdeuce this is still a "demonstration install ". It's almost ready for prime time but not yet in my book. I'm hoping for a client who wants to be my guinea pig for a real world demonstration
I like this idea, but as an engineer and a (former) builder, PLEASE don't call it radiant cooling. As others have said, there simply is no such thing. Cold/cool is simply the absence of heat. Showing a FLIR image of those cool panels on the ceiling implies something that isn't there: that the panels are "radiating" cold. Matt said that there's no moving air. I would disagree and argue that there is passive, convective cooling going on. Hot air in the room rises to the ceiling, gets cooled off by the panels, and it naturally convects back toward the floor. Yes, there is also absorption of the heat radiated by your body and other warmer objects in the room, but my guess is that that is the smaller proportion of heat transfer going on. So... I'm not saying it won't work. I am saying that calling it radiant cooling is a huge misnomer, and a mistake.
It's an accepted industry term. You sound like my math professor when talking about division. No such thing as dividing by a number, only multiplying by a multiplicative inverse. Yet everyone says divide. What would you call it then? Also, so long as you stay above the dew-point, there is no issue with this method of cooling. It can be particularly effective in dry climates as well as homes where natural sunlight can add significant thermal load by way of sun exposed surfaces. Wouldn't write this off. Especially in areas where the system can serve as both heating and cooling.
You, sir, need to crack a text once in a blue moon instead of another episode of Jerry Springer. This is building science. Heat (BTUs) moves from "hot" to "cold". It's a one-way street. "Cold" does not move. "Cold" is an absence of BTUs. Definition is half of understanding. Take away some BTUs and we feel cooler. Ice is water with BTUs removed. A chunk of ice will absorb BTUs in an effort to even everything out. A "ton" of air conditioning removes as many BTUs (12,000) as a ton of ice will remove.
You are confusing hot and cold with thermal energy. Thermal energy is only positive (hot), but thermal energy in a cooling system primary moves through air. Only heat moves, but both hot and cold air move.
After looking at this I have the following observation/comments: 1. The system is complex with a lot of tubing, sensors, and controls. This will result in increased first cost and the need for highly skilled commissioning.2. In humid climates you will need a separate whole house dehumidifier and a way (ductc) for the homes air to reach the dehumidifier.3. The system cannot filter out particulates unless you have a way of moving the air and a way(ducts) to get the air to and from the filter4. These work in commercial buildings when they are engineered for inclusion from the start. A more cost effective solution would be a VRF system.
So the house is lined with water pipes and that connects to a water chiller outside (an ac). The main benefit is water is a better thermal conductor than air so in theory you'd save on how much the compressor needs to run and heating, but if you wanted to try this in an environment with freezing concerns you'd probably need to use a glycol coolant. It would be an entire additional set of plumbing. Also it would be a closed system where you need to worry about corrosion and organic growth considerably more.
This a really neat technology, makes sense and has promise. I wish these people success as I think this is definitely better than most anything I have seen so far. I would like to know what kind of energy figures this is yielding and the energy use under real conditions!
Audacious. I've imagined this would happen eventually but don't know enough to understand the impediments. But it's clear that until this point, they have been insurmountable. Sending you some *positive energy* in support of your proposition. Congratulations on getting your priorities in sustainable order.
Does this work best in dry climates? Will it trigger dew-point/condensation from the ceiling, if used in a humid climate? Is there a good way to dehumidify, when there’s no ducts in a building?
I can't help but notice the guy in the back right with rolled up sleeves and a fan overhead. At first I wondered if it takes more energy to cool air or to cool water, but they have a lot of equipment running for this whole operation, so in order to be beneficial it would need to be cost effficient compared to a traditional AC. Also, the ceiling tiles could be textured in a design like the ceilings in old old biildings.
This is amazing! I can't stand the sensation of hot walls and cold air. Now to make it passive by hooking it up to a gravity fed spring water system! Just gotta tackle the problem of dehumidifying passively.
Had radiant cooling/ heating for a school in Los Angeles school district. The system will only work on mild days, when the temp got above 95 the system was uncomfortable with 30+ kids in a classroom. Now the District is spending millions to retrofit it.
Albert, generals always fight the last war, as the saying goes. People remember the past experience they had in a situation. If the school district purchased inferior quality of a technology that was not yet mature and it was installed sloppily, you will then experience sub-par performance. This does not mean the technology is the fault. In the example, the fault is inferior technology, cheap product and lack or apathy of quality installation and tuning. Heat pump technology is far superior if it is not hobbled every step of the way - especially in a moderate climate like LA. And 30+ kids is like running 30+ 100 watt bulbs, or something like 3-1000 watt heaters.
I talked to Miguel at Positive Energy last year, and this is now his rent house. P.E. has moved to a bigger space, but he says it still works great over 4 years later.
Interesting idea. But I wonder about dehumidifying. With a ventilator the air goes past a much cooler element so can condense humidity out of humid air to blow out dryer air that feels cooler. While this works over a large area / volume and absolute humidity is not lowered at the same rate (with the same energy spend on cooling). Having a separate dehumidifier would seem to use more energy. But this could also work if you'd have a heat exchanger pipes buried in the earth of your yard and pump the water through there.
My grandpa did this with a plaster ceiling in the 70's after he told the home owner that is was a bad idea. The homeowner insisted and was left with a ceiling that cracked and sweat. This system looks better, but I'm still sceptical that the same problems will arise after years of use.
Not sure about down South but in the midwest reliability is a huge issue with water source heat pumps since the shift to 410 and the repair cost was much higher.
i have been thinking about using something like this but instead of a power hungry pump to cool the water just make loops under the ground and use the ground as a heatsink and pump the water through a radiator and you could probably cool atleast a room with like only the energy of a small pump and small fan instead of large compressors and large fans.
The best part about radiant systems is that you can still filter and dry fresh air with dedicated airside systems that require smaller ductwork while eliminating the need for large ductwork for heating/cooling. It's the future.
This had been tried many times - the problem is always dealing with condensation on the cooled surface. Now we have a conventional compressor involved to dehumidify. I don't see the point.
Dehumidifying takes a lot less energy than cooling. I am curious as to the net energy savings, reliability and user comfort aspect of this system. As Matt said he feels it is still experimental and the engineer clearly feels the same as nothing looks to be a finished installation.
At first I didn't think it would cool down my house but then the music at the end starts BLARING and all the windows in my house exploded and now I'm 4° cooler. So thanks for that.
Radiant cooling is useful if you absolutely have to be quiet, like in a studio setting. Otherwise its just alot of useless snakeoil. Sure if you really dont care about costs, you can put in full pipe work in every room, ontop of the ductwork for the dehumidifier, cool the air at the ceiling, cool it even more to dehumidefy and heat it back up to make sure theres no draft from the ducts.
The applications for such a technology is typically in a large landed type property in the suburbs. Is there a reason we are not seeing them why we aren't seeing this applied to apartments in the cities? Would this be a factor of the cooling tank and heat exchange hardware being too large to install in high rise apartment complexes?
I like this idea, but from what I have learned the number one way to save energy is to insulate your house well. Foam block probably the best as of now. And closed cell spray foam in the attic. Even beats solar/wind ect dollar for dollar.
We specify dehumidifiers on air-side systems as well. The fundamental difference here is that the heat exchange potential of water is much more dense than air. So from a systems configuration perspective, it may seem similar, but the fundamental physics going on are vastly different. Learn more about the system here: positiveenergy.pro/building-science-blog/2017/4/24/texas-first-radiant-cooling-heating-system
@@positiveenergy1565I don't see this as something that can replace traditional AC any time soon as is, but this would be fantastic if you turned it into a geothermal system rather than one that uses a chiller. Underground, the dirt will be much cooler than the air temperatures on the surface, so if you run pipes underground you could use the ground as a heat sink to cool the water. the only thing you'd need to run would be a pump, which would cost hardly anything.
@@doctordev97 This system doesn't use a chiller. It uses an air to water heat pump. The performance coefficients of air source heat pumps are about the same as ground source for the most part, and actually work better in central Texas where ground source systems basically spend all their energy dumping heat back into limestone, losing performance capacity over time.
I've been using radiant cooling for 10 years. In the summer, I run well water through my radiant heating tubes. It doesn't sweat because the house is very tight and it's a moderate climate (chilly summer nights knock down humidity).
You should couple the radiant with a low velocity forced air unit from the same chilled water loop to control the humidity, instead of bringing in a whole other system that uses DX. Or else, why depart from DX cooling for this system at all?
heat wicking is the most correct term... "radiant cooling" *face palm* ..... great job insulating your cooling surfaces... this will definitely make for efficient HEAT WICKING....
Radiant cooling was tried in the 60's. it's a complex system to control dew point and prevent sweating. Controls Are still the downfall of HVAC systems.
I like the idea but putting the cooling coils behind drywall seems to be an invitation to mold. I know that the air is dehumidified but what about next to windows and doors? Mold never sleeps and all it needs is food (drywall) and moisture.
Still use substantial power running a chiller to cool a home vs standard AC. It may work good for a new construction but a horrible idea for older homes. It still requires other AC to dehumidify to rooms, use a ton of more energy and is complete bunk
I was concerned with condensation also, love the whole house de humidifiers ect. .. I would think to install it pitched just in case of a failure. I think its a great idea, i would like some kind of fan moving the air around unless it ruins the system.
I suspect this type of system could make for a really comfortable home if used for both heating and cooling but the humidity issue kind of ups the cost factor due to the need for humidity control and the ducting to move the air around.
No doubt radiant works but operating expense is a big question. Plus many depend on evaporative cooling off their bodies to occur at a high rate especially when we have been active outdoors. It seems the lack of air flow inherent in a radiant cooling dominated solution would create an uncomfortable situation as our bodies continue to reject latent heat. Kind of like the need for auxillary fans for athletes in a 70 f domed stadium. Obviously ceiling fans and whole house humidifiers (with ducting) are a solution when coupled with radiant, but total operating costs in a structure with many occupiable and sometimes humid spaces (baths, kitchens, and laundries) becomes a question. In the end, what seems to be the big benefit? As Covey said, we should start with the end in mind.
Major savings in the commercial field. Maybe not as much payback in a home system. I would still use VRF for large homes. But this is their office so maybe they tapped into the existing chilled water. Zoning Hydronics systems is pretty easy.
Can we retrofit this . In a 2 storied 1500 sqft villa..? Do the cilings need to be high to accommodate the the panels? Does it work in subtropic conditions""...
How about some cost comparison data between this and conventional. If it is not more economical, there really isn't much benefit. Just because you can doesn't always mean you should. Great idea. Can you make it more passive, less energy dependent? Is there any ancient technology that you could utilize? Perhaps one pump to push water through pipe embedded in roof and walls. Below ground is about 48 F, perhaps a way to utilize that, year round, heating & cooling?
This was tried in a commercial environment, but because of condensation issues and it wouldn't keep up with rapid temperature changes, it was eventually scrapped! Have you solved any of these issues? Also, it seems less efficient because the dehumidifier has to work more to maintain a compatible dewpoint.
I like the idea, but why the water-to-air heat pump? Couldn't 50 degree groundwater keep the ceiling at 70 or below that? I realize that could take some digging in Texas, but it would be a lot cheaper in the long run.
I don’t see this taking off. You still need mechanical cooling for the humidification. If the humidification is wrong will you destroy all the sheet rock in the house with condensation? It’s a cool idea here but I just don’t see it really taking off too many problems. And you still need air conditioning of some sort for humidity level control
@Matt - have you ever incorporated chilled beams into a build? While radiant cooling and chilled beams appear to be similar in how they cool, your reservations about radiant cooling has me rethinking adding chilled beams to my home build - should I be cautious doing this?
I wonder if he was calling it a "dehumidifier" as more of a figure of speech; there is no reason to run such a device as a dehumidifier (which both heats and cools the air) unless releasing the captured heat outside would make the room too cold. In a well-sealed house, it probably doesn't take as much cooling to remove the humidity as it does to keep the temperature down, so he just needs a conventional AC of a smaller size and the "radiant" cooling to handle the rest of the cooling load.
PC No A "well sealed house" will require fresh air ventilation, and has internal latent loads, so will need a dedicated dehumidification system, even when there is no demand for cooling.
