Hydraulic Radiant Heat

I posted HVAC question recently. I met my architect today and I brought up the question about heatng my new addition with radiant heated floor and possibly baseboard radiator. I started looking for radiant heat info online and could not find any complete information about hydraulic system. I read about various parts (PEX tubing, manifold, zone valves, etc.) However I still do not understand the whole system and what connects to what in what order. Can someone point me to where I can find this info? Also any useful book or other info about installing hydraulic radian heat would be appreciated.

In addition I have a couple of general questions:

  1. Can hydraulic radian heat under wood floors be the primary or the only source of heating? My architect said No, it can only be used or comfort, and need to be supplemented by other heat source.

  1. Is there way to combine boiler used for radiant heating and for hot water? My boiler is small and old and needs replacement anyway. If i decide installing radiant heat in part of my house it would be the best to use the same boiler.

  2. Can wood floors survive heat underneath? I know wood is extremely sensitive to temprerature.

  1. How expensive hydraulic radian heat vs. standard forced air gas furnace? I have electric radiant heat in my two bathrooms and kitchen under tiled floor and it is very expensive to run.

  2. Can the same boiler be used to heat baseboard radiators? My architect said it is the cheapest way to heat th house.

  1. Can hydraulic radian heat installation be DIY? Assuming there is professional layout and calculations done, it seems to me at least part of installation can be DIY.

Reply to
ls02
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I lived in a place with just underfloor radiant, it was the best heat ive had, no cold feet. Here in Chgo it gets to -20 and lower, many places have just radiant, which I think is cheaper to run than baseboard. Baseboard heats the perimiter, radiant is under you since its spread out in the floor so you can feel warmer with a lower stat temp. Radiators on exterior walls loose some heat to the outside heating exterior walls, thats a second reason radiant can be more efficent. Some baseboard need near 180f temp, radiant needs near 110 -

120 which is safe for wood. A condensing boiler looses efficency above about 140f so radiant can be the most efficent for many reasons, and it works wherever you live, you just size it. Your architect says it cant be done, you need a new architect.
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is where boiler pros are. My first choise would be radiant.
Reply to
ransley

Perhaps you need a new architect. Yes, it can be done, I've seen it done.

Yes, but the water may need to be at different temperatures for different uses. Water heaters can be indirectr fired through a heat exchanger and it is very efficient that way.

Yes, it is not all that hot.

Electric heat is often two or three times the cost of oil or gas. I don't know the comparison between the radiant and hot air though, but a good heating contractor may.

Yes, but again you may need different temperatures on different zones if you are mixing heat types. Baseboard runs with water in the 170 to 180 range while radiant is about 120, IIRC.

Yes, there are many different types used depending on construction. Some is done from above, others below.

In any case, if the boiler is old you can save a lot of money with a new one. I had a System 2000 by Energy Kinetics installed last year. My oil bill for the last 49 weeks dropped 39.4% as compared to the 30 year old boiler. Rebates may be available also, as well as tax credits.

Reply to
Ed Pawlowski

First off, you'll have *much* better luck finding information online using the correct terminology: "hydronic radiant heat" or simply "hydronic heating". Not "hydraulic".

An outstanding online resource is

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The best print resource I've ever seen is "Modern Hydronic Heating" by John Siegenthaler. It's a bit pricey:

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It took me six *years* of trying before I was able to buy one on eBay for under $60. You may be able to find a copy at your local library.

Other good print resources are any books on the subject by Dan Holohan.

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You need to find an architect who knows something about hydronic heating. The one you're talking to now doesn't. He's completely full of beans.

Yes, but... You probably don't really want to do that, because it means keeping the boiler active all year long. And it's a chunk more expensive to install. It's considerably less expensive to use a separate water heater.

Of course they can. Wood actually isn't very sensitive to temperature at all; it's humidity that causes problems with wood.

Most sources I've seen say that hydronic is 10-15% cheaper to operate than forced air. It's unquestionably more expensive to install. Much more.

Absolutely.

Yes, it can. I've done it myself (not an entire system, just a couple of rooms), and the results have been excellent. But I spent literally hundreds of hours studying the Siegenthaler text and making and checking and rechecking my calculations. It's *not* easy.

Reply to
Doug Miller

Perhaps there are hydraulic cylinders rubbing two big hands together in order to produce heat? The hydraulic heating system could make the house shiver when it gets cold, thus warming things up through friction.

TDD

Reply to
The Daring Dufas
  1. Can hydraulic radian heat under wood floors be the primary or the only source of heating? My architect said No, it can only be used or comfort, and need to be supplemented by other heat source.

SM: Should be possible. Hydrionic lacks the ability to AC or to filter dust out of the air. If you use pure water, the pipes could freeze during a power cut.

  1. Is there way to combine boiler used for radiant heating and for hot water? My boiler is small and old and needs replacement anyway. If i decide installing radiant heat in part of my house it would be the best to use the same boiler.

SM: Yes, I've worked on systems with an indirect heater, which heats water for showers, dishes, etc. Should be possible to combine them. Of course, that's the time to consider which fuel to use. Some parts of the world, fuel oil, natural gas, or propane. Based on what's available, and what's most reasonably priced.

  1. Can wood floors survive heat underneath? I know wood is extremely sensitive to temprerature.

SM: Should be fine. During the winter, you'll be wishing for a humidifier of some kind, or your house will massively dry out.

  1. How expensive hydraulic radian heat vs. standard forced air gas furnace? I have electric radiant heat in my two bathrooms and kitchen under tiled floor and it is very expensive to run.

SM: Installation, I don't know. Operation cost varies, with the cost of fuel. Most areas, cheaper than electric, very much so.

  1. Can the same boiler be used to heat baseboard radiators? My architect said it is the cheapest way to heat th house.

SM: Baseboard radiators are different temp than Wirsbo, but it should be possible.

  1. Can hydraulic radian heat installation be DIY? Assuming there is professional layout and calculations done, it seems to me at least part of installation can be DIY.

SM: I've known families who did much of the install themselves. The one family I know, when they had the cement floor poured, the tubes to the heating manifold got shifted, and the manifold was too close to the floor, and crooked. He wasn't at all pleased.

Reply to
Stormin Mormon

Pfffft. Hydronic radiant heat doesn't dry out a house anywhere nearly as much as forced air does.

Reply to
Doug Miller

Both hold the indoor temp without adding humidity. Why would one be worse?

Reply to
Stormin Mormon

Thank you for the info. I of cause apologize for "hydraulic" it indeed needs to be "hydronic".

I will sure get and read "Modern Hydronic Heating" . If I decide to go for radiant heat and the more I read the more appealing it sounds I will have to DIY most of the work or I won't be able to afford it. I myself installed electric radiant heat in two bathrooms and kitchen, though I realize it is nowhere that complex as hydronic system. I won't take on putting a design myself, what system to choose and what manufacturers (I did some search online and they are quite a few). Ideally for me I would pay someone to do this design, advice me on what to buy and where to put the system and I will do most or all of the work. However ,I don't know where to start. I don't believe we have in our area HVAC contractors who do radiant heat. I live in relatively affluent area in Central NJ (average house here is around $550K) I don't know anyone who installed hydronic or any other radiant heat.

Reply to
ls02

The air from a forced-air heating vent is *much* hotter than room temp, and its relative humidity is therefore lower.

Reply to
Doug Miller

adding humidity. Why would

and then it cools and goes up.

Reply to
ransley

And, the hot furnace air mixes with the room air. The room ends up being the same temp. Forced hot air doesn't remove any water, just changes the RH based on temp change. Neither hot air, nor floor heat adds or removes water, unless the hot air has a humidifier installed.

I don't see any difference.

Reply to
Stormin Mormon

Never lived in a house with radiant heat, have you?

Reply to
Doug Miller

I personally liked radiant floor heating, as much my dog too. Very comfort temperature of warm floors instead dry and overheated air from forced air heating system.

Reply to
sherwoodarcher

The dry air issue on forced air can be solved with a humidifier that will maintain humidity at whatever you like. I've never understood the claimed issue with forced air heat being "dry". The issue would seem to be that any air that is heated will have a drop in relative humidity. The air gets heated the same whether it's forced air, baseboard or radiant. A furnace doesn't magically extract water from the air. I can understand that different heats may be perceived differently and you may prefer radiant for that reason, but I don't see how radiant heating would maintain humidity levels, while a forced air furnace would not. Unless the forced air system is leaking, sucking outside air in somehow, which may have been a factor in decades gone by. But seems to me a perfectly working forced air system would result in the same relative humidity inside the house as any other system.

Reply to
trader_4

ONLY FORCED AIR allows air conditioning, and forced air furnaces, at least gas approach 100% efficency

Reply to
bob haller

In theory, forced hot air can be filtered, humidified, ionizied, odorized, de-farted, radiated, and anything else you may want to do with it. But is not usually done right.

I think the real issue is combustion air and the intake and venting. No matter the fuel, if you are sucking combustion air in through the leaking windows and doors, burning the heated air and then venting up the stack, it is going to be a dry climate.

We have HW baseboard and had to run a humidifier in the winter for comfort. When the boiler was replaced, the new one draws combustion air from outside directly to the burner leaving the rest of the air in the house alone. It is more comfortable as the humidity drops less by comparison.

The forced air may also feel dryer as it is blowing around. Never did any measuring though, but people's perception, real or imagined, is that hot air heat is dryer. It does not have to be.

Reply to
Ed Pawlowski

I agree. But at time marches on, more and more furnaces have combustion air brought in from outside. Worst case would have been a furnace in the living space that did not have outside air. I can see that making a big difference in indoor humidity.

That confirms what I was saying.

Agree.

Reply to
trader_4

Couple things to think about:

Forced air can heat, cool, and dehumidify. Hydronic can only heat. What d o you need?

Either can heat the room to any given temperature.

Forced air can be from a furnace or a heat pump. Heat pump air delivery te mperatures are usually cooler and some people don't like that. But they ca n get the room up to whatever temperature you want. Forced air especially from a furnace can be faster to heat the room than hydronic.

Stormy is right about relative humidity. It doesn't matter how you heat th e room air. What matters is the tightness.

I had hydronic heat in Wisconsin. In the winter the air stayed too dry reg ardless of how we tried to humidify. It was typical old frame house constr uction with lots of air changes (meaning outside air replaces the inside ai r at a regular rate). I had hydronic heat in Germany in a similar climate, but the opposite happened. The house was very tight due to masonry and pl aster construction, well designed windows and doors. Unless we opened wind ows a couple times a day, water condensed on surfaces and mold grew, just f rom the humidity added by people breathing, cooking, and showering.

Reply to
TimR

That's my personal theory.

Reply to
Stormin Mormon

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