Buying a house - hydronic heat?

[grandmajo]

Hi all,

My DH & I are buying a home that was foreclosed upon. We're rather excited because it's not finished on the inside (dry-wall needs mudded, only sub-floors are laid, needs kitchen installed, etc)

This home is a 2 story built into a hill, with a walk-out basement. The basement has hydronic heat installed in the floor. Those of you that have this type of heat, could you share with me the pros and cons?

[suitcase_sally]

I have hot water heat, but mine is baseboard radiator type. I love it! I grew up with forced air and hated it! Cold one minute, warm the next. Always had noisy furnace to deal with and dry air being forced down from the ceiling. Hot water heat is very even heat. One of my neighbors built a new house a few years ago and put in the heat when he poured a concrete floor (no basements here, the water table is too high).

[agmantoo]

On warm days and cold nights the residual heat from the night will overly warm the house as the sun rises and warms everything. If you turn the heat low or off and return home needing heat it will lag the need as it will be slow to warm up the home. The heat is nice and clean and on very cold days the warm floor is great.

[strawhouse]

Our primary heating source is hydronic. (radiant floor.)
It is a wonderful feeling walking on warm floors, and can be an extremely cheap way to heat a home, depending on what you heat the radiant with.

Floor coverings make a huge difference to the efficiency of radiant floors. Bare concrete is best, followed by tiled floors. The heat radiates easily through it. (rammed earth works well too, if you like the look)
Some people will install wood or laminate floors over their floor. While the heating will still work, it's efficiency is drastically reduced. (Though hardware stores and manufacturers of wood products will tell you differently.) Wood is a "thermal break", and doesn't transfer heat well.
Don't put wall to wall carpet on the floor. You're just paying money to heat a floor that's insulated by carpet and foam. The heat won't transfer through enough for you to see any benefit from the floors.

Is there any type of heating system installed for the floor yet?
We have a combination of solar hydronic panels, a coil in our woodstove, and a backup demand propane water heater. We estimate the panels produce about 70% of our hot water. (both for heat and for bathing.)

The pumps, amount of radiant loops in the floor, and the setup of the entire system make a huge impact on how the floor works. (My hubby has installed quite a few sytems in houses, and fixed 2 of our friends systems to work more efficiently.)
If there is no system set up yet, you really want to do your research to find out what would work best for your house. There's no real one size fits all approach.
A good quality thermostat, meant for radiant floors goes a long way too.

Sounds like your getting a great house! Being built into a hill will help with the heating costs too, and really help the efficiency of your hydronic system!

We don't have a problem with overheating during the day as agmantoo does.

[grandmajo]

Originally Posted by strawhouse

Our primary heating source is hydronic. (radiant floor.)

Is there any type of heating system installed for the floor yet?
does.

Right now it's set up with an electric water heater type boiler. In fact the house is total electric. I was a bit concerned so I called the electric co-op. And was really surprised when I found out what the electric bills ran. Much less than what I thought they would be.

Of course, we're open to options for ways to improve on the system, so we'll be doing some research.

Thanks everyone for your replies!

[Chixarecute]

We love our radiant floor heat - have it in basement (in concrete), and on first & second floors installed under the subfloor. Heat source is a commercial water heater, natural gas. The heat is very even, and we find we are more comfortable at a lower temp than when we had forced air (67 vs 72). In spring & fall, when the boiler doesn't run much, the tile floors do get a bit cool. BTW - you can put carpet over radiant, just don't pick a real thick, hi pile carpet.

[where I want to]

I have it in my house but don't use it much. It did make a wonderful heat- at a much lower setting it provided a comforting warmth- the floor, wall, etc seemed to be warmed.
But I have a propane water heater to heat that system and it was too costly for me.
But it is very comfortable.

[strawhouse]

Originally Posted by grandmajo

Right now it's set up with an electric water heater type boiler. In fact the house is total electric. I was a bit concerned so I called the electric co-op. And was really surprised when I found out what the electric bills ran. Much less than what I thought they would be.

Of course, we're open to options for ways to improve on the system, so we'll be doing some research.

Thanks everyone for your replies!

We ran our system first on an electric hot water tank for a few months. Not too costly, but overall cost us the most.
Then switched to a propane boiler, as it was more efficient cost wise. This was still the temp plan.
Then we set up the system we have now. We're still working on the best way to get the most heat out of the woodstove and into the floor, but this is the final system setup for sure!! (Things get added to the house as money allows)
Our propane costs for the winter, this includes the hydronic heat, cooking, and hot water ran us about $450 last year. This was for Sept to May. We had a pretty cold winter last year too. (About $56 a month I think)

Is the house facing south as well? Sounds like a fairly well designed place, maybe it incorporates passive solar as well?

[Kris in MI]

We have the radiant floor hydronic heat. Love it!! We do have to plan ahead at the beginning of the season because it takes 6-12 hours to get 'up to speed' rather than just flipping a switch and having instant hot air through vent with forced air. But it does stay warm evenly, no cold spots, no drafts, and wow how great it is to get out of bed in the morning and have your feet hit WARM floors!

Originally ours was heated by a propane boiler, but three years ago we got a great deal on and outdoor wood boiler, and since we have 10 acres of woods and access to lots of free wood from friends, storm damage clean up, tops of timbered trees at the neighbors, etc, we have heated solely with wood since Dec. 2007.

[cc-rider]

How do you use the hydronic heat on 1st and 2nd floors? I assume they are wood subfloors? I'd like to do something like that but figured that since they weren't in a concrete floor, they wouldn't work.

[Chixarecute]

The loops of pex are installed from underneath, & attached to the bottom of the subfloor. There are a few different ways of attaching. You do have to drill holes between the joists, make the initial out & back run, then pull the loop into position on the farthest joist space from the "back" run of the loop, attach, then go to the next closest joist space. You can then use plain old fiberglass insulation batts (unfaced), or specially made reflective foil, before closing in the ceiling.

The most important thing to remember is that loop lengths within the zone should be as similar as possible, shouldn't exceed 250 feet long per loop, AND that the manifold is at the high point of the floor it serves, it always goes ABOVE the floor it services.
Even though it is a closed system, air does build up over time, and one of the jobs of the manifold is that auto air bleed feature.

There's an absolutely wonderful public building in our community with radiant floor heat that is a cold bugger, because of the airlocks that developed over time - the manifolds were installed above the floor, but the loop tubing to the manifold is routed over the manifold, then comes back down to the manifold - air bleeds don't work, can't work. The system worked fine for a few years...

[Gianni]

The advantages compared to forced air are less cost during the cold months. The initial cost is generally greater.
In the warmer weather say 40F-50F forced air is cheaper to run. You can't add AC to hydronic heat. Other than those two if it is closer to 32F or less for more months than it is 40F-50F you are ahead.