Home>Discussions>INSULATION & HVAC>Radiant heat stapled to subfloor
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canuk
Re: Radiant heat stapled to subfloor

Well .... this sure has a familiar tone.:rolleyes:

Now that you have settled on your revised post v1.3[COLOR=black][COLOR=black]........ let's try and[/COLOR] [/COLOR]decipher what the heck you're talking about ....... without the need to get into any kind of drawn out debate about your opinions , conjectures and disjointed Google tidbits.

Since there aren't any pros. in the field of hydronic heat contributing here ... I had a conversation with one regarding this topic and got some information based on his expertise..

fact ..... There are 3 methods of heat transference ... conduction .... convection ... radiation.

The type of heating system we are talking about here deals with all three.
Warmed water flows through tubing and by conduction ( in this case ) transfers heat to the floor above. In cases aluminum plates or fins are attached to the floor with the tubes attached to these plates to help transfer and dissipate the conducted heat better.

The floor surface above absorbs this heat energy and emits this energy to the room above. Some objects in direct contact with the floor will absorb heat through conduction and emit radiant energy .... other objects not in direct contact will receive the radiant energy from the floor's surface .... as well convention heat will occur from the air within the room.

The amount of heat flow is dependent on the amount of energy generated by an object and is proportional to its surface temperature. With the temperatures dealing with the heating system and objects at room temperature ….. most of the thermal radiation is lower energy infrared . This is one reason thermal imaging is effectively used with infrared cameras when an energy audit is done.

In this case ….. thermal insulation materials are used to reduce the rate of heat transfer by conduction and radiation.
The flow of heat is reduced by the physical properties of the materials used which the resistance these materials provide.... heat flow will take the path of least resistance.

BTW ... heat doesn't rise ... it will flow up , down , sideways .... wherever there is no resistance ..... warm air rises.

Blue RidgeParkway wrote:

Nope that is wrong.

The only thing wrong was inferring this would be the only way to insulate.

However ... since the original poster asked a basic question without any details it's easy to assume they may only have common insulation materials such as fiberglass batts .... which case I don't believe it's necessarily wrong.

The point of using thermal insulation is valid in providing resistance to heat loss by providing a path of least resistance .... which is up toward the floor above.

Warm water tubing used for in floor heating is commonly placed directly onto an insulating base such as rigid foam sheets ..... with no air barrier and reflective materials. Besides .... in the current TOH project I believe Richard laid the tubing directly onto a foam base with channels to house the tubing.

So ... I would guess by your account Richard is also wrong.

Regardless if it's a "wet" system embedded into concrete or a "dry" system attached to the subfloor .... the principal is the same.

Quote:

[COLOR=blue]Bev in Mass,

sorry but spouse is right but you should have reflective barrier and canuk is wrong.

when you have joists you need a gap then you put the reflective barrier an inch or so below the radiant heat the reflective barrier is important and the gap is more important.

and you don't insulate without a reflective barrier in place.[/COLOR]

There is no requirement anywhere to have to have a reflective barrier when it comes to this type of system.

As the heating pro mentioned ... there is usually an up charge to the reflective materials and the quality matters.
Many installations will have the reflective materials because .... they can charge more for the product .... and the installer doesn't have to bother with dealing with fiberglass batts.
He went on to explain you can achieve effective results using materials like fiberglass or mineral wool insulation just that density matters..... depends on the budget.

Quote:

[COLOR=blue]the way i remember it was similar to the necessary air space between the reflective low E film in windows and the inner glass layer[/COLOR]

[COLOR=black]There are three major types of coatings on the market: soft, hard, and Heat Mirror.

Soft coat is directly applied to the surface of a finished piece of glass. It's not durable enough to be exposed , so it's only used on the inner surfaces of windows.

Hard coat is not quite as energy efficient as soft coat, but is tough enough to be applied on exposed surfaces.
Hard coat is produced by fusing metallic oxide to the hot surface of glass

So there is no air gap with these radiant barriers.

Heat Mirror is a product that's applied to a thin polyester sheet suspended between the two panes of dual pane window.
The coating reflects radiant heat while the sheet decreases heat loss by splitting the air space in two.

[COLOR=black]The air space in these types of windows is used for thermal insulation between the 2 panes of glass.[/COLOR]
The air is effective as a thermal barrier when it's not allowed to move .... one of the main reasons the glass panes are hermetically sealed.

These coatings are helpful when the windows are uncovered …. When the drapes are open during the day ……for example.

Closing the drapes creates a resistive barrier to the infrared and depending what and how thick the material is … can minimize or eliminate the infrared reaching the window.

But this thread is not about windows ……
[/COLOR]

Quote:

[COLOR=blue]that the reflective film surface provided little in thermal resistance in itself [/COLOR]and if in direct contact with the radiant heat source without the one inch air cushion would transfer the heat directly to the wood joists and insulation pocket like a conductor instead of a reflector back to the subfloor.

the air pocket is necessary to be reflected and if cold below then also insulated from all six sides of the subfloor area like Mike reminded otherwise you get air currents in the air space or it (heat) goes up the walls like a chimney or conducts heats to the rim joist and heat transfers to the outside wall = heating the outoors.

[COLOR=blue]i do remember that air in that space is considered fluid.
[/COLOR]

[COLOR=black]You're contradicting yourself by saying .... " [COLOR=blue]the reflective film surface provided little in thermal resistance " .... isn't that the purpose of the reflective barrier?!?[/COLOR]
Otherwise .... why would you be using it?

The main advantage of quality radiant barriers is the characteristic of high reflection with infrared thermal radiation. Depending on the quality and material used as well as it reflectivity ....a small portion of radiant thermal energy is absorbed by this material with most being reflected away . Apposed to materials with low reflectivity that will absorb a large portion of thermal energy ...... which in turn emit a large portion.

[COLOR=#000000][COLOR=#000000]However …. these are not necessary to function as thermal barrier
[/COLOR]
Interesting point raised by the pro ... since this reflective material lays flat inside the joist cavity under the floor .... they will get covered with dust as time goes on. Unless you were to clean the surface regularly it will have a reduction in performance the more dust accumulates.

This is a downside …. The reflective material needs to be a good quality and it’s performance is reduced when it becomes dirty or covered with a layer of dust.
[/COLOR]

The effectiveness of an aluminum foil radiant barrier in preventing conduction is negated if it contacts any material with high thermal conductivity.
For the Reflective foil to function adequately ..... it needs to rely on an adequate air gap as a conduction insulation barrier between the heat source ( the tubing in this case ) and the foil.

However .... because this space is not hermetically sealed and the need to have an air gap .... convection currents are present. Which means heat loss will occur if this air can move from the warm zone to the cool zone.

[/COLOR]

canuk
Re: Radiant heat stapled to subfloor
Blue RidgeParkway wrote:

if you need an example of reflective barriers and long wave infrared and how it works you can build yourself a reflective oven chamber and use it to melt a jar of snow in it at mid day in the middle of winter.

Simpler yet ……

Take a ceramic or glass cup of hot coffee …. The hot liquid is transferring it’s heat to the ceramic or glass by means of conduction.

Place your hands near the edge of the cup and you feel heat being radiated from the surface area of the material.
Cover the cups surface with insulation and you find the cup is no longer radiating heat. The insulation provides thermal resistance reducing or eliminating the thermal radiation.

This is the reason a styrofoam cup is effectively used and without any reflective foil.

Quote:

i am sure they have loads of testing about their products and efficiency but whoever wants to know WHY could easily ask the manufacturers or look it up themselves if they cared to know why since they didn't know HOW in the first place. maybe things need to be done different in the tundra or arctic circle or Alaska but not Mass.

Based on your statement it would seem that Mass. doesn't follow the laws of nature , physics , thermal dynamics as the rest of the world.

sabo4545
Re: Radiant heat stapled to subfloor

Hopefully this will lay this issue to rest. This is directly from the Onix installation manual (which it sounds like the original poster has Onix and not Pex because it is a direct staple up and did not use the heat transfer plates).

You can view the entire installation manual at

http://www.wattsradiant.com/pdf/OnixInstallationManual.pdf

Frame Floors
Introduction
Of all the radiant applications, frame
floors offer the most installation flexibility.
Over 80% of all residential radiant
projects have at least one form of a
frame installation. Of these, the
Staple-Up™ application is the most
common.
Frame floor projects allow for easy
installation of a radiant system, for
new construction or renovation. Even
though some installation details vary
from application to application, basic
design considerations remain the same.
The most important goal is to make
sure the Onix is in direct contact with
the subfloor.
The second most important detail for a
Staple-Up™ application is to properly
install foil-faced batt insulation below
the tubing. If a non-foil-faced insulation
is used, the system may operate
with a 25% loss of maximum heat
output and some (smaller) loss of efficiency.
Other insulation can be used
instead of a fiberglass batt, however,
certain cautions need to be observed.
1. Tight seal. One of the largest areas
of heat loss with any underfloor
application is convective loss
through the band joists and other
perimeter areas. The tighter the
joist cavity, the better the system
will perform.
2. Foil Face. The foil on the
insulation will ensure most of the
heat and energy coming from the
tubing is reflected up to the subfloor
where it is distributed. The
foil also spreads the heat out over
the subfloor. This in turn reduces
what has been called thermal striping.
3. Air Gap. A 2"–4" air gap is necessary
between the tubing and the
insulation. This air gap helps
increase the effective R-value of
the insulation while fully optimizing
the ability of the foil insulation.
The main goal is to keep the tubing
from coming into contact with the
insulation. If contact is made, energy
is no longer reflected upwards,
but rather, is conducted downward.
This can reduce the effective heating
of the floor by 10% to 20%,
depending on the load conditions
and thickness of insulation.
4. R-Value. As a rule of thumb, an RValue
of at least 4 times higher
than the floor is desired. For most
indoor conditions, an R-13, or a
3-1/2" batt should be used. When
installing over an unheated area,
exposed area or crawlspace, a
minimum R-19 or 6" batt should
be used.
Design Parameters
With any new or renovation project, it

Blue RidgeParkway
Re: Radiant heat stapled to subfloor
Windebrook wrote:

Hi, I was wondering if anyone could tell me how to install insulation over radiant heat stapled to under side of subfloor. Should we leave a gap/pocket between insulation and subfloor or should we push insulation right up against the subfloor and tubing? I say the latter as I feel with a pocket, we are wasting energy to heat the joists to either side, but spouse vigourously objects. Thank you, Bev in Mass

canuk wrote:

Based on your statement it would seem that Mass. doesn't follow the laws of nature , physics , thermal dynamics as the rest of the world.

Poor Bev. Sad Canuk!

According to Bev's post: this isn't in the floor radiant heating its NOT over the floor radiantit is UNDER THE FRAME FLOOR stapled to the subfloor radiant heat! between joists and it is stapled up UNDER the subfloor, the original poster said so[/U].

Canuk, you are comparing apples and oranges and doing so incorrectly, and don't get into the mass of slabs thats oranges and carrots and your nuts! your coffee cup and styrofoam example was as laughable as it was irrelevant.

Oh, and by the way from Bev's description you should have been able to figure out it isn't necessarily hydronic radiant either. the air SPACE necessary for installation of insulation, the reflective barrier optimal.

for the arrogantly ignorant and those who just don't KNOW:

How is heat is transfered:

Heat is transferred from one location, or body, to another by three basic modes. These modes are Convection, Conduction and Radiant Heat.

One basic rule to all three modes is this: heat does not rise, hot air rises. Heat moves from a hot source to a cold source. Think of a hot air balloon. It floats because the hot air inside is less dense than the cool air outside. This literally causes the balloon to float in much the same way a boat floats on water.

Another way to think of this is to imagine a metal skillet placed on a stove burner. When the burner is turned on the handle is still cool to the touch, but as the bottom of the pan warms, the heat moves from this now warm source, to the cooler outer edges. Eventually the handle will become too hot to handle and a cooking mitten will be required to handle the skillet

The three modes of heat transfer:

Convective heat transfer is what most of us are familiar with. This is how our forced air heating system or our baseboard system transfers energy (heat) to a space. Air moves over a heating element, becomes warmer and expands into the space. In a forced air environment, most of the hot air is at the ceiling, much the same way the hot air balloon rises, so will the warm air in a room heated with forced air. Convective heat transfer is the least efficient means to transfer energy.

Conductive heat transfer refers to two surfaces touching each other. Imagine a metal pan on the stove. If your hand is positioned an inch above the hot handle, you really won't feel much from the handle, and you can keep your hand there as long as you wish. But, when the handle is touched, your hand instantly begins to feel hot. This is conductive heat transfer. The pot is giving off the energy (heat) in the handle to your hand in a very fast, efficient manner. Conduction is one of the more efficient modes of heat transfer.

Radiant heat transfer is the best because it isn't slowed down by air. Radiant energy is only felt when the energy wave strikes another surface. This means the surrounding surfaces all reach set temperature. By enclosing your body by warm surfaces, we can better control how our bodies lose heat. Radiant floor heat means better comfort with higher efficiency.

Next we consider moisture and its effects on the frame floor throughout the seasonal year in the state of Massachusetts and how we must consider that in our design.

kentvw
Re: Radiant heat stapled to subfloor

Does anyone else recognise a most familiar pattern? ..... Creepy.

Blue RidgeParkway
Re: Radiant heat stapled to subfloor
kentvw wrote:

Does anyone else recognise a most familiar pattern? ..... Creepy.

The pattern: booger boy the trapped ferral neutered tom cat, squirts one off and howels, in a desperate attempt to mark every thread to inflate his ego and expand his territory.

BOOGER BOY OPENS MOUTH, STEPS IN IT, THEN INSERTS FOOT IN MOUTH, THEN LOOKS TO VOMIT ON AND BEGIN AN ATTACK TO MISDIRECT ANYONE IN THE ROOM THAT SAW HIM DO IT and isn't a part of his bully boy possie network who swoops in attack mode to misdirect obsucate and drown the thread in sewage. Booger Boy calls in Snot Nose and the rascal gang of drooling and screetching jackals, vultures and hyenas to circle, swarm, screetch, and feed while Booger Boy tries to hide the IT he vomited up along with the hairballs and worms, and licks himself in the corner.

Creepy and predictable pattern, yep.

canuk
Re: Radiant heat stapled to subfloor
Blue RidgeParkway wrote:

Nope that is wrong.

Bev in Mass,

sorry but spouse is right but you should have reflective barrier and canuk is wrong. when you have joists you need a gap then you put the reflective barrier an inch or so below the radiant heat the reflective barrier is important and the gap is more important. if you want to insulate (like cold zone below) then that insulation goes right beneath up against the reflective barrier. you do not insulate with direct contact when you have joists and you don't insulate without a reflective barrier in place.

i know it has something about the air space being necessary for a reflective barrier to work. the way i remember it was similar to the necessary air space between the reflective low E film in windows and the inner glass layer and how the radiating heat energy you can't otherwise direct back to the subfloor when you have joists was/is long wave IR. that the reflective film surface provided little in thermal resistance in itself and if in direct contact with the radiant heat source without the one inch air cushion would transfer the heat directly to the wood joists and insulation pocket like a conductor instead of a reflector back to the subfloor. the air pocket is necessary to be reflected and if cold below then also insulated from all six sides of the subfloor area like Mike reminded otherwise you get air currents in the air space or it (heat) goes up the walls like a chimney or conducts heats to the rim joist and heat transfers to the outside wall = heating the outoors.

keeps the return water warmer protects from the cold below and sides = more of the warmth in the water retained on the return to boiler = fewer gallons of oil (BTUs) or gas to heat it back to temperature = lower fuel bills and higher efficiency. most important it makes the floor more responsive meaning it gets warmer faster also requiring less BTUs overall.

basically the radiating heat energy wants to go to the coldest spot it can so you deflect it to the floor or focus it with a mirror like reflective barrier. the only thing you want touching the tubes besides the subfloor is what touches the subfloor you are heating to direct diffuse transfer the heat to, no reason to heat the air pocketed insulation, the rest of the heat that radiates you want to reflect direct back to the floor to heat it that way. i do remember that air in that space is considered fluid.

if you need an example of reflective barriers and long wave infrared and how it works you can build yourself a reflective oven chamber and use it to melt a jar of snow in it at mid day in the middle of winter.

i am sure they have loads of testing about their products and efficiency but whoever wants to know WHY could easily ask the manufacturers or look it up themselves if they cared to know why since they didn't know HOW in the first place. maybe things need to be done different in the tundra or arctic circle or Alaska but not Mass.

Blue RidgeParkway wrote:

Poor Bev. Sad Canuk!

According to Bev's post: this isn't in the floor radiant heating its NOT over the floor radiantit is UNDER THE FRAME FLOOR stapled to the subfloor radiant heat! between joists and it is stapled up UNDER the subfloor, the original poster said so[/U].

Canuk, you are comparing apples and oranges and doing so incorrectly, and don't get into the mass of slabs thats oranges and carrots and your nuts! your coffee cup and styrofoam example was as laughable as it was irrelevant.

Oh, and by the way from Bev's description you should have been able to figure out it isn't necessarily hydronic radiant either. the air SPACE necessary for installation of insulation, the reflective barrier optimal.

for the arrogantly ignorant and those who just don't KNOW:

How is heat is transfered:

Heat is transferred from one location, or body, to another by three basic modes. These modes are Convection, Conduction and Radiant Heat.

One basic rule to all three modes is this: heat does not rise, hot air rises. Heat moves from a hot source to a cold source. Think of a hot air balloon. It floats because the hot air inside is less dense than the cool air outside. This literally causes the balloon to float in much the same way a boat floats on water.

Another way to think of this is to imagine a metal skillet placed on a stove burner. When the burner is turned on the handle is still cool to the touch, but as the bottom of the pan warms, the heat moves from this now warm source, to the cooler outer edges. Eventually the handle will become too hot to handle and a cooking mitten will be required to handle the skillet

The three modes of heat transfer:

Convective heat transfer is what most of us are familiar with. This is how our forced air heating system or our baseboard system transfers energy (heat) to a space. Air moves over a heating element, becomes warmer and expands into the space. In a forced air environment, most of the hot air is at the ceiling, much the same way the hot air balloon rises, so will the warm air in a room heated with forced air. Convective heat transfer is the least efficient means to transfer energy.

Conductive heat transfer refers to two surfaces touching each other. Imagine a metal pan on the stove. If your hand is positioned an inch above the hot handle, you really won't feel much from the handle, and you can keep your hand there as long as you wish. But, when the handle is touched, your hand instantly begins to feel hot. This is conductive heat transfer. The pot is giving off the energy (heat) in the handle to your hand in a very fast, efficient manner. Conduction is one of the more efficient modes of heat transfer.

Radiant heat transfer is the best because it isn't slowed down by air. Radiant energy is only felt when the energy wave strikes another surface. This means the surrounding surfaces all reach set temperature. By enclosing your body by warm surfaces, we can better control how our bodies lose heat. Radiant floor heat means better comfort with higher efficiency.

Next we consider moisture and its effects on the frame floor throughout the seasonal year in the state of Massachusetts and how we must consider that in our design.

Blue RidgeParkway wrote:

The pattern: booger boy the trapped ferral neutered tom cat, squirts one off and howels, in a desperate attempt to mark every thread to inflate his ego and expand his territory.

BOOGER BOY OPENS MOUTH, STEPS IN IT, THEN INSERTS FOOT IN MOUTH, THEN LOOKS TO VOMIT ON AND BEGIN AN ATTACK TO MISDIRECT ANYONE IN THE ROOM THAT SAW HIM DO IT and isn't a part of his bully boy possie network who swoops in attack mode to misdirect obsucate and drown the thread in sewage. Booger Boy calls in Snot Nose and the rascal gang of drooling and screetching jackals, vultures and hyenas to circle, swarm, screetch, and feed while Booger Boy tries to hide the IT he vomited up along with the hairballs and worms, and licks himself in the corner.

Creepy and predictable pattern, yep.

LOl ....Your reaction is predictable :rolleyes:

kentvw
Re: Radiant heat stapled to subfloor
Blue RidgeParkway wrote:

The pattern: booger boy the trapped ferral neutered tom cat, squirts one off and howels, in a desperate attempt to mark every thread to inflate his ego and expand his territory.

BOOGER BOY OPENS MOUTH, STEPS IN IT, THEN INSERTS FOOT IN MOUTH, THEN LOOKS TO VOMIT ON AND BEGIN AN ATTACK TO MISDIRECT ANYONE IN THE ROOM THAT SAW HIM DO IT and isn't a part of his bully boy possie network who swoops in attack mode to misdirect obsucate and drown the thread in sewage. Booger Boy calls in Snot Nose and the rascal gang of drooling and screetching jackals, vultures and hyenas to circle, swarm, screetch, and feed while Booger Boy tries to hide the IT he vomited up along with the hairballs and worms, and licks himself in the corner.

Creepy and predictable pattern, yep.

Yeah........... That is what I mean. It always works this way. In all the people you have tried to be, and who have been banned as, well, you.......... It has been this way for years.......In all honesty I hope you are well one day. Leslie, the rest of us have gotten along for years here. We have had a good time and helped many people......... The only problem has been you.

I wish I had kept a file of your classic posts of hate from years ago........... I keep one now. It is named simply the Fetid File........... This is included in the file.

BTW....... We (Me and the pretty lady here) are all ready for a party at my home right now...... Just trying to figure out how to keep the damn fireplace going! LOL!

Yum! Awesome! She just made peppermint brownies to have with peppermint and chocolate chip ice cream for desert……….. Wow………. She may be a “keeper.”………. Maybe she thinks the same of me……………………..LOL!

canuk
Re: Radiant heat stapled to subfloor
Quote:

Does anyone else recognise a most familiar pattern?

absolutely ... no doubt .... contrary to her sig line.

Blue RidgeParkway wrote:

Creepy and predictable pattern, yep.

__________________
false rumors insulting comments arent made true by repeating them often. dictators terrorists hate mongers & gangs expand their power base when the majority and those charged to protect them suffer from apathy inattention & laziness.

Yes indeed.

kentvw
Re: Radiant heat stapled to subfloor

All it is, is sad.............

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