Hello everyone,
I recently purchased a 100 year old house, and plan on renovating the bathroom. One of the problems with the existing bathroom is the lack of heating. Is it possible to use the hot water lines to run radiant floor heating? I would only want to turn it on when the bathroom is in use, and turn it off when finished.
thanks for any suggestions/comments,
Simon
Replies
I heated two bathrooms with a combination of electric baseboards and an electric cable thing under newly laid ceramic tile.
You might consider electric heaters in the toespace under vanities.
One of your local HVAC contractors can advise whether your hot water heater will support a small area of hydronic heating. It won't be cheap. The setup might involve pumps, controls, mixing valves, etc.
The cable heat guys (SunTouch, EasyHeat, etc.) will all tell you that the floor warming systems cannot be relied upon for heating, but I can tell you that the comfort of having warm feet goes a long way.
I think using the hot water supply for in floor radiant heat would have too slow a response for heating the bathroom while in use
Now, if you wife gets up first ....
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hey SBAILLIE I have the same situation on the horizon and my solution at this time involves in wall heaters that proved problematic in some situations so if this is any where near where you are heading SBAILLIE chime in you electricians et all...
first I'd second all above other than think of in the floor electric as auxiliary ( if much tile on floor involved - maybe mandatory )
what I have installed many of are the cadet wall mount heaters - every client has only had positive responses BUT they were recalled for potential fire risk problems*** they have very efficient fans that tend to bring in and accumulate copius amounts of dust/lint in a small space next to a heat source
anyway have they resolved those issues - if so IMHO they are hard to beat 110 or 220 volt ( 220 best for heat ) I install ext. wall usually eliminate the thermostat after governing about 40% below top heat ( frugal SOB I am ) and set on the wall wired to a timer at the door and within 5 minutes you can have a Cancun type atmosphere and that sucker will turn off whether your wife is 5 minutes late cuz she forgot where her keys are or your son just never turns anything off - good dry sauna like heat and only when you need it
I have seen a number of systems that performed well using the bathroom supplied hot water. There are towel warmers that you can install on a wall using the shower/tub destained hot water, toe kick space coil types with a blower, and I have been in a number of hotels with radiant floor heated tile using only the bath water line. Toasty tile floors by the time you get out of the shower, are super, and the floors stayed warm long enough to dry the floor quickly. I intend to use a water line grid under the bath tile in a house I am designing now. Good luck. Paul
>>I have been in a number of hotels with radiant floor heated tile using only the bath water line.
But rememebr that hotels are constantly circulating the hot water in a loop so there is always hot water at hand.
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Bob, true, they recirculate the hot, but the only time the floors heated was when we used the tub or shower, regardless, hot had to arrive before jumping into the shower. They were just using some of the heat from the water on it's way to the spray head. I don't know what method they used to keep from sending very hot water to the floor, but the shower water "hot" was way above the 85 deg. we hear about for rfh max.
Also,
Bob, what's the word on health if using an open system, and using the tubing water (cooking, showering etc., after standing idle for months in the summer? I am contemplating running a line for toilet refill from the cold side manifold, so the a few gallons are pulled out each day from the "stale" water all summer.Energy Consultant and author of Practical Energy Cost Reduction for the Home
Paul,
The 85 degree "limit" is for the max temp to the finished floor. For the circulated water to get the floor to approach that temp, often times the circulated water can be 110 to 140 degrees, though a more common range is 110-120.
Does that "MAX" apply to hardwood finished floors, or engineered floors? (as opposed to MDF based laminate) ?
I have seen plenty of floors that were way above 85 in the sun, but not for extended periods, of course.Jake Gulick
[email protected]
CarriageHouse Design
Black Rock, CT
It's somewhat of a murky area.
In general, the guidelines I've used are a max of 87.5 degrees for non-wood...tile, etc.
A max surface temp of 80 for solid strip wood floors. Long term elevated temps can cause excessive drying and gapping. Some engineered (ply structure, good quality) floors can go to 85, it's usually mentioned in their specs.
For glue-downs, 85 is usually a max, 80 is better. Elevated temps over a long period of time can cause some glues to crystallize, become brittle, and fracture under use.
If the design warrants a high temp from the floor, then either supplemental heat of reducing the rooms loss can bring things back into alignment. There are usually ways to tweak the system to get what's needed.
Mongo, Thanks, I realize the 85 is floor surface, but was wondering about tubing touching the thinset directly under the ceramic tile. A hotel in New Zealand, and another in Japan had the floors heat very rapidly as soon as the hot water to the bath was turned on. You could feel the floor respond with your feet in just a few minutes as the wave of heat spread through the tile. Shower water was hot, especially in Japan where they take baths we would find too hot. What would 140 degree tubing feel like in thinset/tile, or what would copper feel like in same situation? I don't know how they did it, but I loved it, and the bath mat dried rapidly as well. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home
I'm not sure if I should go with cable heaters under the floor, or hot water. Either sounds like it will work well for my application. I think the electric cables are probably much simpler to install than the hot water.
The house is heated with forced air oil heat, but ther are no ducts into the bathroom. I think that as long as the floor is warm (I'm putting down tile) it will stay comfortable in the bathroom.
thanks
Simon
Simon,
Does the "lack of heating" mean an absence of heating, or just not enough heating?
If "just not enough", your best and easiest bet is to supplement the existing heat with electrical cables under tile. You can either buy wire on the spool and you run the loops, or some manufacturers have the wire embedded in a plastic mesh for an easier layout.
Warm floors will go a long way to making a chilly room fell not so chilly.
In retrofitting a small room like a bath to provide radiant as the main source of heat for the room, sometimes it's not economically feasible to do so. Much depends on how the existing house is heated, and the proximity of the bath to the existing heat source.
Raidiant run off the bath's in-use hot water lines couldn't be expected to warm the floors until after you're done using the bath. Response times could be expected to be 60-90 minutes or so.
Recently installed radiant heat (Easy Heat) under bathroom tiles. With the right spacing a comfortable room temp can be acheived. The room was fine even during a few minus 30 degree days in January. I think the wire offers much more versatility than the mats.