Direct Vent Fireplace

[JimD]

We bought a 50 year old, under insulated house last year because it is on a large lake. It is also brick with nice landscaping and a layout we can work with. But when the temperature goes below freezing, the heat pump cannot heat the house to 70 degrees. When it was in the teens it wouldn't get to 60 degrees in the great room, the main issue. The great room is almost 25x25 with 16.5 foot ceiling. The old heat pump has heat strips but just isn't large enough. I've had a HVAC guy look at it and they say it is functioning fine, just to small to keep up. I added insulation in the attic which helped but didn't solve the problem. I need to insulate the floor but I also need to change the bathrooms so I am waiting until I get the bathrooms done.

The other reason to change the fireplace is my wife doesn't like the smell of wood smoke. The fireplace draws well so there isn't much odor but she still doesn't like it.

So I am about ready to buy a direct vent fireplace that will fit into the existing fireplace in the great room. There is a local shop that will do the installation (if I pay, of course). It will have to be propane, we don't have gas at this house. The propane company is ready and willing to put in either a 120 gallon tank or two 100 gallon tanks. They check the 120, I have to switch between 100 gallon tanks and call for another to be dropped off if we go that way.

I'm looking for experience with direct vent fireplaces, especially if you happened to use propane. Can I get meaningful help with heating? Will cost be OK? Would you get a 120 gallon or two 100 gallon tanks? Other thoughts?

 

[ehpoole]

Have you considered having an energy audit performed for your house? Many power companies will perform them for little to no cost. Theses audits are concluded with a series of recommendations to reduce energy use, particularly with respect to improving heating and cooling efficiency. In some cases there may even be rebates available to help offset the costs of some upgrades (availability varies considerably).

Insulating the floors will certainly help. However, many older homes have little, and in the South, sometimes no, insulation in the walls as well. It is possible to add blow-in insulation to walls if needed, but there can be a lot of holes in the drywall/plaster to patch up afterwards (best done prior to painting the interior walls). Older windows and leaky doors are also major areas of heat loss in older homes. Also, older ductwork was often very leaky and sometimes uninsulated, which can result in a lot of energy and heating/cooling lost to the outdoors before it even has the chance to warm/cool your home. Such ductwork can either be upgraded or replaced to reduce losses and can improve the apparent capacity of your existing system by reducing losses.

Enjoy your new house!

 

[JimD]

The walls are insulated with R11 batts. Ceiling areas that I haven't retrofitted have R19 (I have raised them to R30 or higher where I could). I had all the windows replaced with high efficiency units last year. Ductwork is flexible insulated ducts. I still have somewhat leaky old doors that need replaced (they are solid wood with single pane glass in them). I also got a professional type Great Stuff foam dispenser that I use each time I discover another leak. I've used up a bunch of tubes of caulk on the outside too. I still have more weather-stripping to do but I think the next big thing will be the floor insulation. Maybe I will replace the back door first, it is the leakiest. My wife wants a French door, however, so all that glass won't be very terribly energy efficient either.

 

[ehpoole]

The walls are insulated with R11 batts. Ceiling areas that I haven't retrofitted have R19 (I have raised them to R30 or higher where I could). I had all the windows replaced with high efficiency units last year. Ductwork is flexible insulated ducts. I still have somewhat leaky old doors that need replaced (they are solid wood with single pane glass in them). I also got a professional type Great Stuff foam dispenser that I use each time I discover another leak. I've used up a bunch of tubes of caulk on the outside too. I still have more weather-stripping to do but I think the next big thing will be the floor insulation. Maybe I will replace the back door first, it is the leakiest. My wife wants a French door, however, so all that glass won't be very terribly energy efficient either.

You can get insulated doors with double-pane glass, so, as long as they seal tightly, the doors need not be a major source of heat loss/gain. Just a matter if opting for more efficient doors, and there are still plenty of styles to choose from.

 

[Gotcha6]

You might also look at a ceiling fan in that tall room. A lot of your heat is staying on the ceiling and needs to be forced back down. Counter-intuitively, reversing the fan rotation in the winter to pick the air up and force it back down around the perimeter makes the room warmer and you don't feel a draft while under the fan.

 

[Bas]

I'm looking for experience with direct vent fireplaces, especially if you happened to use propane. Can I get meaningful help with heating? Will cost be OK? Would you get a 120 gallon or two 100 gallon tanks? Other thoughts?

I have a vent free fireplace in my current house (natural gas) and had one in my previous house as well (propane). They give off a ton of heat, since none of it goes into a chimney or to the outside. The current one I have I bought five years ago from northern tool and it's worked great. It has a fan to disperse the heat and a remote.

i also have a direct vent fireplace (natural gas), with fan. It produces a decent amount of heat, but not nearly as much as the vent free ones. The quality of the installation is very important to get good efficiency. Whether it will be enough depends on the size of the fireplace you're getting if it's a retrofit, you are often limited to a smaller unit, which may not be sufficient for the room.

 

[Jeff]

Floor insulation. Take a look at the post by blazeman45 in this forum. Roxul insulation. It looks like pretty good stuff that's efficient and easy to work with.

 

[Jeff]

Can I get meaningful help with heating? Will cost be OK? Would you get a 120 gallon or two 100 gallon tanks? Other thoughts?

You're fighting an uphill battle (I have a bias against heat pumps). Maybe consider replacing your undersized heat pump with a new gas pack (propane) unit for starters.

because it is on a large lake

Maybe a geo thermal heat pump that uses the lake water instead of ambient air.

http://energy.gov/energysaver/articles/geothermal-heat-pumps

 

[JimD]

I want to have a contractor spray closed cell foam in the crawl space for floor insulation. If the cost is too high, I am thinking of the covered fiberglass batts. Floor joists are 2x10s so I have room for R-30. The foam would also seal up leaks and would help avoid damage if the lake ever floods (but our framing is well above the 100 year flood level). That is my thinking. I'm thinking of the wrapped fiberglass if I go that way both to avoid itchy installation but also to avoid the dangling mess that typically results from fiberglass in the crawl space.

The builder that did the addition said the existing wall insulation is rock wool.

 

[ScottM]

I have a ventless fireplace in the family room with 10' ceilings and a open layout floor plan. It can keep it 70+ with no issues especially when I run the ceiling fan blowing up. When I did it the gas company would only install a single 100 gallon tank next to the house. It I wanted to go with two tanks or a large tank it had to be buried of moved so many feet from the house per code.

 

[Pyrut]

Insulate the floor with the foam (quick and easy) tell the bride to get used to an occaisional whiff of smoke and burn your scraps and firewood . Nothing like an open fireplace. Make sure you have an inplace or on-top damper to close off the fireplace. Lacking either, stuff a large cushion in the flue when not actively burning. This for a man that lives alone and likes it.

 

[JimD]

I've had a ventless gas fireplace before and we didn't like it. It seemed to stink up the house after an hour or so. They do put off heat.

A ceiling fan is in the plan, maybe soon. We also need more light so it will have a big light kit. I have it picked out, I just haven't purchased it because I was doing the expansion areas. Those are done so maybe finishing the GR will be next. It needs the ceiling painting edged, the fan/light put in, and some caulking around the beams (one real, 4 fake).

 

[junquecol]

As for insulating floor, get a couple of prices. Often you can get it done for about what you would pay for insulation alone.

 

[HMH]

Not to thread hijack, but has anyone w/ a direct vent fireplace had any issues w/ drafting coming around the enclosure? Our propane direct-vent in the living room works great when it running, (rarely), but the area around it is significantly colder that the rest of the house when it's turned off, I'm assuming from the cold outside air, super-cooling the aluminum fire box and seeping into the house through the blower vent when it's not running. From what I understand, the typical "dog-house" bump-outs around these boxes are not insulated, ours being no exception.

If you are adding an insert to an existing chimney structure however, this problem shouldn't be an issue for you.

 

[JimD]

You're fighting an uphill battle (I have a bias against heat pumps). Maybe consider replacing your undersized heat pump with a new gas pack (propane) unit for starters.



Maybe a geo thermal heat pump that uses the lake water instead of ambient air.

http://energy.gov/energysaver/articles/geothermal-heat-pumps

Another guy in the office is building on the same lake and went geothermal. It raises the efficiency significantly and should solve the issue with it not being able to keep up in extreme cold (because the lake doesn't fluctuate like the air). It also raises the cost significantly for the coil you put in the lake. And you need permits. Still it is something I will probably look into at some point. The unit that can't keep up is also getting old so..... This house needs lots of "stuff" done to it so it is a question of what gets fixed first.

 

[junquecol]

First, the existing damper in your fireplace is WORTHLESS! It's a cast iron assembly which doesn't seal very well. We have a Lyemaurce Chimney top damper which is spring loaded. It snaps shut when closed. But if you install either vent free logs or fireplace, the building code requires that the existing damper be blocked open a quarter inch. This means you always have a quarter inch crack in damper, whether logs are in use or not. I have installed several infa-space heaters in fireplaces for emergency heat. Because they are not approved for recessed mounting, I put them on a pull out tray, with flexible gas line. When needed, you pull them out, and when not needed, push them back in, and cover with fire place screen.