We live in a drafty old house in Minnesota and dread our winters. We dream of a newer, tight home with radiant floor heating, but don’t see it in our future (we’re old house junkies). But what I wonder if it would be feasible to add radiant heat to our first floor (accesible from the basement) to at least make the downstairs cosier. We have forced air heat currently, could we comingle the two heating sources?
Your thoughts would be appreciated.
Thanks
Replies
Yes, it's feasible. There are several different below-the-floor schemes that can be used, employing either hot water or electric resistance heating. Generally these schemes employ a preformed metal strip that fills most of the width of the joist bay and conducts heat from the heat element (pipe or wire) across the width of the bay. Then insulation is added below this assembly.
Can't begin to guess about cost, though.
We need a lot more info.
How big is the house.
What kind of construction and how old.
What kind of boiler/furnace and how old.
Does the house have any kind of insulation.
Radiant flooring is nice but a lot of things can be done to make an old house more comfortable and energy efficient.
You should also post your Q at http://heatinghelp.com/
Yes. As Dan said, there are several ways to do it. Around here, the HVAC guys would probably switch you to a boiler from your furnace, use it to fire the water for the heat in the PEX under floor, then add a couple of heat exhangers to the existing duct system that blows warm air through the rest of the house to keep it in use if it is still good.
A lot though depends on conditions. There are cellar spaces in some old homes that make it almost impossible to do this work and really drive costs up.
Also, keep in mind that hardwood floors don't always like underfloor heat systems.
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I beg to differ very politely about hardwood and radiant floors.
If there is a problem I would look for other suspects.
Hardwood will perform perfectly well over a very wide range of temperatures.
Think of the temp of the floor in front of large south facing panes of glass in mid summer. Well in excess of 100 degrees and no impact on floor performance.
If the supply temp to the floor is so high then there are other issues related to heat loss or system design that demand too high temps.
Sorry to disagree :)
I don't think we disagree. I only said that wood floors and radiant don't always get along.Part of that is that for radiant to function most efficiently, it needs mass. A wood floor and subfloor are more of an insulator than a mass, so installing there means using the AL plates to increase conductivity to the floor, and avoiding shrink and cracks in the wood ( and sometimes added creaks and squeaks) means adjusting the mixing valves lower than in concrete. And you need to insulate under it so the cellar is not warmer than the floor aboveI have installed a lot of radiant under wood, but just pointing out that there are things to overcome and work to do to deal with the issues.
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I think we're all dancing around the issue with slightly differant perspectives..
While there is a tiny amount of resistance to thermal transmission (R value) in wood, wood does have a mass.. thus once it heats up it will provide a heat source of it's own. While it won't retain the same amount of heat that a stone will, it does have mass and thus can yield heat.
Plus we also need to remember that it's moisture not temp that causes wood to move.
My own house is a good example.. there is 3 inches of wood between the source of heat (the Pex tubing wrapped in aluminum) my floors are nice and warm. because of the efficency of the insulatiuon in my house it's enough in 95% of circumstances to meet my heating needs with a small heat source.
If the heat loss is too great then in floor radiant heat won't be enough. but that depends on too many variables to discuss here..
Thanks for the various inputs but I need to make concern clearer. My concern about the temperature on the second is not that they would be too hot due to hot air rising, but that it will be too cold since the thermostat is on the first floor. How can I balance temperatures with a radiantly heated first floor, and a forced air system that "heats" the whole house. If I move the thermostat to the second floor it may make the first floor too hot, but if I leave it on the first floor, the furnace may never run to heat the second floor. Can you see my dilemma?
Why not add a radiant zone to the second floor?
The mark of the immature man is that he wants to die nobly for a cause, while the mark of a mature man is that he wants to live humbly for one. --Wilhelm Stekel
Adding a radiant zone to the second floor sounds way more complicated than putting in the first floor radiant heat from the basement. We do have whole house AC. I suppose I could shut off the first floor vents in the winter. Maybe I'd need a summer thermostat for downstairs and a winter one for upstairs. Lots of food for thought here.
Thanks
With PEX adding a new zone shouldn't be such a big deal. It could be baseboard, vs in-floor.But just adding a second tstat upstairs and shutting off the downstairs registers would probably work fine.
The mark of the immature man is that he wants to die nobly for a cause, while the mark of a mature man is that he wants to live humbly for one. --Wilhelm Stekel
Or zone the forced-air system, or simply shut off registers on the first floor and move the thermostat to the 2nd floor.(BTW, do you have whole house AC?)
The mark of the immature man is that he wants to die nobly for a cause, while the mark of a mature man is that he wants to live humbly for one. --Wilhelm Stekel
It would be cheaper and more productive to seal the house with the money you will spend on radiant.
easy and cheap to do if you have access to the bottom of your floor.
Contact radiantec (they advertize in Fine Home Building and are a regular contributor here)..
Tell them what you want to do. They will do the engineering for you and all you have to do is put it up.
There is a tiny premium for their services but then you won't have to do the claculations and you know everything will be right and fit right.
In retrospect I wish that's the approach I'd taken. I engineered my own system and made about 40 bizillion trips to the store. Frankly it all arriving via truck appeals to me so much having done it the other way that I suspect what little bit I saved in seeking out cheaper sources I wasted in gas going and getting them..
The house was built in 1888, it's a 2 story Victorian, stick built. We have vermiculite insulation poured into the walls and attic floor spaces. There is asbestos in the insulation so we don't want to disturb it. I hoped that the radiant heat would help make the main living floor more comfortable. One concern though is the second floor - how can I control heat upstairs if the first floor is warmer? Any ideas
At the risk of inducing a 'zen' moment ..... "become the draft.'
That is, consider exactly what makes up a draft.
A draft is simply the flow of cooler air. It need not be air coming in from outside; even an airtight house could have some terrible drafts.
For example, my house had a terrible draft in the front room, one that I blamed on gaps around the door. Try as I might, I could not eliminate the draft, no matter how I sealed the edges. Well, the draft disappeared the instant I covered the inside of the door with an inch of foam. The steel door, itself, was creating the draft by cooling the inside air.
Naturally, the preferred way to eliminate a draft is to eliminate the cold surface that creates it, by insulating. Failing that, the direct application of heat - say, a heat lamp pointed at the patio door - might prevent the draft from forming. Finally, a heat source that the draft encounters will break up the draft.
Another approach that can work is to reverse the airflow .... that is, making the cold air flow 'up', and bring warm ceiling air down. That's what a ceiling fan might do. It won't help the heating bill, but you'll feel warmer.
That's where hot water radiant heat excells; wherever there might be a draft, there's a pipe full of hot water.
best of luck w/ a solution but in response to your last line and someone more informed could explain why etc but you remarked about how to control heat in floor above 7 I'm taking that to mean you are thinking ( yes heat always rises ) all that heat will go upstairs but that isn't the rule w/ these hydronic heated floors - it hangs lowfriend in Gloucester Mass had to add auxiliary to an upstairs; half of which was open to downstairs
Perhaps to clarify if I may.
HOT AIR rises, heat radiates.
Think of the sun all those many miles away with nothing but cold space between.
No heat until the sun's rays touch us. A cloud obscures the sun and we feel colder.
Radiant heat warms what it sees not the air in between.
Think of a campfire, only that which faces the flame is warmed while the part in shadow is not.
Cheers