Why is it so trendy to hate on radiant in-floor heat?
IHeartSikka
| Posted in Mechanicals on
I recently built a 2000 square foot house in climate zone 7. The building is two stories on a slab heated by a Navien 240a combination boiler. There is no heat source on the second story, and the simple system has only one zone, which is all it needs because all the rooms in the house stay at the same temperature–maybe it’s a few degrees cooler in the upstairs bedrooms if the doors are shut for 24 hours or more. I spent just over five grand on the heating system–installed–although I got a tankless water heater in the process, so the real cost was more like $3500. How is that overkill?
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Josh,
You got an excellent deal. Congratulations. In other parts of the country, the price for your system would be considerably higher.
Simple 1-zone slab-radiation systems are pretty cheap to build, and are fairly DIY-able for those who take the time to read up on it and are sufficiently handy.
But the installed cost of a Navien combi boiler alone would be WELL over $3500 if installed by a licensed plumber / gasfitter in my neighborhood. In my state (MA) DIY work on gas heating equipment installation is disallowed- it requires a permit to be pulled, and installation by someone with the necessary licencing credentials (and insurance / bond) as well as an inspection. Bootleg installations could result in the house being condemned or denial of a certificate of occupancy. YMMV
Bootleg... I'm with Alex... what bull pucky situation. Gov is too damn big folks. Same with the high cost of geothermal and PV. Too many dang Gov rebates hinging on "authorized installers." I would love to install my own PV and get the all the rebates... nope, it's a racket.
Same with building codes... I love em.. and would also love the right to placket my home as not inspected.
I brush my teeth without inspectors observing and even hit the john unassisted....
"I brush my teeth without inspectors observing and even hit the john unassisted...."
Not for much longer. Big government zealots don't understand the phrase "Now we're done, let's call it a day." There is always more to regulate.
Congratulations . You are now the proud owner of the radiant floor heating system Martin has been rallying against . Hope you enjoy those overheated Southern rooms because they are on the same zone as the rooms on the North that require heat . Maybe you'll have to wear a sweater in the North rooms because the stat is in the South side so it does not overheat .
You'll also really like replacing that combi since it will shortcycle like a madman even at design in your super tight house . Bet you or your installer have no idea what heat flux and MRT mean , much less varying tube spacing to successfully achieve what has been done in your house . This is exactly why it is so trendy to hate on radiant floor heating . Hey , look at the bright side and remember this , when your system does'nt work like you were told I'll be on heatinghelp.com with many other quality designers and installers to get you straightened out , See ya there .
In any case , when you need him , your installer will not be around anymore . How could he possibly be not knowing that you must make money .
Don't candy-coat it for him Richard, tell it like it is! :-)
Not every DIY radiant slab project is a complete hack (even if most are.)
It's possible to mess up any type of HVAC installation. But it's certainly easier to mess up a hydronic radiant floor than a ductless minisplit installation.
I always do Dana . Possibly to my detriment , hopefully it helps most .
I dunno Martin, the more idiot-proof they make things, the more creative the idiots become. :-)
There was a lot of truly horrific pre-packaged hydronic slab designs based on tankless HW heaters being perpetrated on the web a decade or so ago. Hopefully most of those have gone away by now (but I'm afraid to even look.) But if you build a really efficient building envelope even the bad designs can be comfortable enough.
You guys hit back pretty hard with this stuff.
In our area there is ZERO design help for radiant, it's not used much here. There's a few online companies but, I don't trust a designer in Maine to design my system 500 miles southwest. Maybe I'm wrong...??
There are decent designers who can help you remotely, then there are the others. A hydronic designer who can demonstrate some level of competence and is selling you the DESIGN particular to your house and climate (and Manual-J) can work fairly well. It's WAY better than a web-store selling a bunch of "heats any home" hardware, along with some napkin-math instructions on the website on how to design & hook it all up.
It can be hard to separate the true pros from the hacks though, even when they're standing in front of you. It's always good to study up on it and do at least some of the basic heat load and hydronic design math yourself, if only to weed out the proposals. But even that isn't perfect. Several years ago I reconfigured the hydronic heating system at my house and handed the sketched out design to some contractors, with the expectation that they would complete the math. A hydronic designer at the outfit I hired swore that it wouldn't work, even when I showed him the math. The owner of the company was a plumber who had been in the trades for decades and understands quite a bit. He took a look at the sketched out math and said it probably WOULD work, but insisted that he not be held liable if it didn't. He then bet his own designer $100 on the outcome (and collected!) It wasn't clear to me which aspects the pro found fault with (and never had the face-to-face discussion with him), but I thought I was playing it conservatively enough in the sketch design.
RMILLS .
Good designers / consultants can tell you preety much whatever you need to know . They will ask lots of questions about how you live , DHW usage if applicable , wall assemblies , ACH rates , finish floor surfaces and construction .
After all that and much more , I have limited time tonight , they will perform a heat loss and make recommendations allowing you to choose a couple options possibly .
I regularly send multiple hours worth of science based stuff so potential customers actually understand that heat does not rise and many other common misinformation is false .
I will often tell people if radiant floor is a good option for a particular room or not and offer solutions . After that discussion they will send loads of papers that include step by step instructions and budgets . Ones that truly care take complete responsibility and will locate capable contractors in your area and vett them fully then give you 3-5 to let in your door . At least that's how I do it
Hint . Do not look up radiant heating on the internet and if you do stay away from 1 from Montana , 1 from Vermont and 1 with radiant floor in the name . Anyone who says you can operate an open system on a combi appliance and anyone who says " heat rises and we heat the air . WRONG .
If this si something you are looking for visit a site like heatinghelp.com . State your business and have a pleasant experience .
Richard,
you sure do a lot of advertising all over different forums for your website.
To RMILLS: Heatinghelp.com is not Richard's website. It's the GBA equivalent for hydronic and steam heat.
Reply to Josh Jipson,
Here's my take on the anti radiant floor movement, because I've lived it:
Radiant started getting trendy again the 1980s with the advent of cheap plastic pipe (don't use copper).
Those of us interested in green building thought it had some advantages for comfort and efficiency. Others like Robert Bean also thought it's healthier.
After I installed my system in 2004, I realized that in a really well insulated and air sealed house, the system doesn't come on much. Therefore the concrete floors are almost always cold. So in my case, I could've heated my house with hot air for half the installed cost with nearly the same efficiency and comfort.
Additionally, in the years since 2004, PV has come down in price, and air source ductless minisplit heat pumps have become the new trendy way to heat for a few reasons:
1. You don't need natural gas or propane in the house.
2. PV can "heat the house" when the heat source is electric.
3. Solar thermal never did work out as a heat source for homes.
4. Minisplits are 2-3 times more efficient than electric resistance heating.
5. So PV combined with minsplits has emerged as the easiest and best mechanical route to net zero for a residence.
Thanks Kevin . It's a shame that someone did not know about constant circulation in your house using ECMs or that lower temp water around 75* under those conditions would heat your type of house real nice using hardly any energy . Is standby loss really standby loss when it is being used ?
RMILLS . Kevin is right , I do not have a website . Most of my work comes from industry professionals whom have projects that require proper design , I will not drop names .
The rest of the time I diagnose , repair , redesign installations done by those with flashy websites . You'll only see my work in industry publications and when I post terrible jobs done poorly to show what not to do and how to fix it when it does happen . It happens alot as many here can attest to since it is trendy to hate on radiant
Apparently he sold this house .
http://forum.heatinghelp.com/discussion/154140/is-there-a-heating-expert-richard-mcgrath-on-here#latest
Radiant in-floor heating needs to be installed by the best of the best for it to work properly. Sadly, 90% of the time it is not installed by the best. IMHO the cost, complexity, problems, and long term issues does not justify it in most cases.
I've seen it installed in mild climates where it MIGHT get used 1-2 months per year. Even then the chances of it overheating the rooms are great.
While I appreciate and do not disagree with most of what you said Peter a PROPERLY designed radiant heating system has NO CHANCE of overheating any room . Thus the word PROPER .
Maybe it is better expressed in this way . In a majority of the homes discussed within the confines of GBA Standards and practices supply water temp on a design day would probably be sub 85*F . With outdoor reset which would be a must in my world the temp would never be higher and as we all always tell everybody , design occurs less than 5% of the time . Please take into consideration that this designer would never put a room with a southern exposure on the same zone as a room with a northern exposure . Is anyone able to tell me how the radiant in a PROPERLY designed system could overheat a room when it is not running ? Furthermore , how can fluid that is lower in temp than the slab contribute any heat ?