Heat Options for Cold Bathroom

[FarmDiesel]

Our master bathroom is on the Northwest corner of our house and, with constant winter winds from the north and west, it gets very cold in there. I'll try to give as much background info as I can before I pose my question...
1. First floor bathroom, no windows.
2. Below the bathroom is crawl space that is adjacent to full basement. No insulation in the floorboards between crawl space and bathroom.
3. Above the bathroom is attic; ceiling of bathroom is insulated with 6" batting (R30).
4. Ceiling of bathroom has stand-alone, high-CFM (200?) bathroom vent fan that vents to outside via a dampered, uninsulated 10" rigid, round duct.
5. Floor of bathroom is tile over 3/4 TIG plywood. (Cold, cold tile).
6. Due to bathroom layout, there's not much room for baseboard heaters. 1 wall has the sink, 1 wall is shower, 1 wall is bathtub, and the other wall is toilet/door. There is a small area on 1 wall where an in-wall, electric heater could be installed.
7. Room has 1 air vent into it; does not have a cold-air return in the room. There is also no cold air return in the master bedroom (but the master has 2 heat vents). House has natural gas, forced-air heat.
8. Room is off of the 1st floor master bedroom; bathroom door is left open (but we'd like to keep it closed).

I could get one of those electric heaters that are built into the wall, but I really don't like the idea of doing that unless it is the only option. Ripping up the tile floor is not an option, so in-floor heat is out unless I can run it under the plywood somehow? Cost effectiveness is a major concern, as always. Should I try insulating above and below the room more, or should I consider supplemental heat? What's likely to give the best bang for the buck? I'd like the solution to be: effective, aesthetically pleasing, efficient, and economical. Any thoughts?

[spaz1]

maybe try a heat lamp in conjunction with your bath fan. i have one and it works great.

[Ernest]

I would use a oil filled heater from wally world, never had a problem with it, don't have to worry about exposed heating elements, and it costs around 50 bucks. [img]/forums/images/%%GRAEMLIN_URL%%/whistle.gif[/img]

[hapaschold]

any air coming out of existing air vent ? perhaps the duct has become disconnected or a damper has closed.

electric radiant in the floor is real nice way, but dont know if they make kits for below subfloor install.

the in ceiling heat lamp is good idea also as mentioned above, just be sure to keep insulation away from the housing.

[David C]

I would definitely insulate below floor immediately. To add foot comfort (and also add to insulating quality) in the winter, I would also add some carpet to the floor. That really helps over my tile floor, and it can be removed for the warmer months.

[NickKent]

You've got some tough parameters. There are a few things I would address right off. Insulate the floor asap. Install a inline damper in your vent fan as close to the outside as possible. Now, I'm guessing the roof over your bathroom is vented since the ceiling to the bathroom is insulated. Chances are you are losing heat through the R30 fiberglass since it doesn't seal very well. I would yank the fiberglass in your ceiling and have a dense pack or damp spray cellulose sprayed in on the ceiling. You want to aim for as much R value as you can get. The more the better. If you can afford it have the floor insulated with a closed cell spray in foam. A bio based water blown foam has an R value of around 5-5.5 so depending on your joist depth it will do much better than fiberglass and seal air leaks. By the way, how thick are your walls and what is in them for insulation? Do you have rigid foam on the walls to prevent thermal bridging of the studs?

[CEMeyer]

I installed a fart fan with a heater element in it, in the bathroom of my parents old house. Worked wonders. It seems like it was about $350 and it required a separate circuit for the heater.

[checkthisout]

Originally Posted by CEMeyer

I installed a fart fan with a heater element in it, in the bathroom of my parents old house. Worked wonders. It seems like it was about $350 and it required a separate circuit for the heater.

This is probably the best option.

They are like 90 bucks at Home Depot for a Heater/Fan/Light combo.

The heater is forced-air and about 1200 watts. More than enough for a cold bathroom.

The fans on the cheaper models are kind of weak but I have one in a 72 square foot bathroom with a 10 foot high ceiling and it works great!

As you stated, a seperate 20 amp circuit is required along with of course all the wiring running from the ceiling to the triple switch.

[LC]

Originally Posted by Checkthisout

This is probably the best option.

They are like 90 bucks at Home Depot for a Heater/Fan/Light combo.

The heater is forced-air and about 1200 watts. More than enough for a cold bathroom.

The fans on the cheaper models are kind of weak but I have one in a 72 square foot bathroom with a 10 foot high ceiling and it works great!

As you stated, a seperate 20 amp circuit is required along with of course all the wiring running from the ceiling to the triple switch.

I second this option. We have one and the heater works great. Start it up about ten minutes before taking a shower and the bathroom is all toasty. The exhaust fan is a little lame but works to some extent. I have no idea of the brand name as it has been in for about fifteen years now and nothing shows on the unit itself.

[short_stuff]

I also did this for both bathrooms at the lake house. It helps a lot. They also make a radiant floor heater that can be installed under the floor. My thought is that with plywood, and then tile and mortar, you'd be using up a lot of energy before you saw any heat in the floor. Good news is that if you ever decide to retile the floor, the electric grid would be perfect to lay under the tile.
And insulate under the floor if at all possible, even if you plan on doing other upgrades later on. My lake house is on blocks, and during the winter, the wind blows right off the water and under the house. After I insulated the entire downstairs under the house, it was amazing how much faster the house would warm up and stay at temperature. The tile floor in the bathrooms both downstairs and upstairs are comfortable enough to walk on them in bare feet.
I also agree that the hvac vent may have a rip in it, or has come undone up in the attic, for the bathroom to not be getting the heat it needs. If its just weak flow in the vent, you could look into getting a booster fan installed in the feeder trunk to push more air to the bathroom.
Also, look to make sure the exhaust vent lid isn't being forced open by the wind blowing on that side of the house, blowing cold air back through the exhaust vent. just my .02 cents worth

short_stuff

on edit: When I had my central air and heat units installed a year ago, I noticed that they used flexible 8 inch ducting that was actually 14 to 18 inches wide because of the insulation around the actual duct. Might be worth investigating to see if you're losing too much heat in the attic because of the older style duct work. just a thought

[David C]

Have another idea that will help short term, at least, if you have incandescent light bulbs in the bathroom. Leave them on all the time and keep the door closed 24/7. These bulbs put out enought heat to warm the room considerable if the door is kept closed to reduce airflow outward. Should be much more comfortable when the room is used.

I have a bathroom in an unheated garage. In winter to prevent pipes from freezing, and make the seat a little more useable, we do the above using two 60 watt bulbs in the ceiling fixture. Even when weather is in the teens for several days, no freezing as the bathroom temp remains about 55 degrees.

[eagleeye]

If you really want to address the cold tile problem you can buy sections of radiant heat mesh and install it between the floor joists in the crawl space. You will then want to put insulation between the joists. You will have to run a new circuit and snake wires in the walls. It takes some labor and a few bucks, but it is well worth it.

[Riggodeaux]

How big is the bathroom? I ask because it will effect the size vent fan/heater you might install, and also whether lifting and replacing the tile [so as to install under-tile electric heating 'blanket', which is great! Nothing better than a warm time floor in a bathroom] is something you really should consider. By all means, follow the tips about improving your insulation, below, above, and the damper in that huge 10" vent duct - you might want to reduce the size of the duct, which is way large for any but a huge bathroom, and may be conducting more cold into the room than it is exhausting warm, damp air. Depending on room size, check out a combination vent/heater. I installed a Panasonic that worked great in our last house, quiet, direct heat to where we needed it, vented through 4" pipe, I believe. See the panasonic and nutone $250 models at ventingdirect.com; both reasonably quiet 9.9-1.1 somes] with around 110 cfm of exhaust ...

[FarmDiesel]

The bathroom is approximately 100 square feet...but the flooring is relatively new and I'd rather not go ripping it up.

Anyone have any experience with laying the electric heating grid under the subflooring and then insulating as suggested above? I didn't think that would work...

[eagleeye]

If you google or yahoo "radiant heat flooring" you'll get a large aray of suggestions. I just installed "warm tiles" brand in my master bathroom and love them. I can't remember exactly, but you can buy the heating elements that are integrated into a mesh for fast installation. I would measure how wide your floor joists are and purchase this product accordingly. I will concur that installing this system under the subfloor may not be as efficient as on top of the subfloor, but you will notice a difference with proper insulation. You have to remember that you have one very important law of nature working in your favor here, heat rises.
On another note, according to your post, your tile was installed on top of the 3/4" T&G subfloor. I hope there is fiber or cement board under the tile. I have seen guys install it this way before and it normally lasts about 1 1/2 to 2 years before it starts cracking the grout and eventually the tiles. With yours being directly over a crawl space, the elements of expansion and contraction on your plywood or OSB subfloor will not lend your tiles to a long service life.