Direct vent insert heating capability without power

[lethal dose]

Hey! Looking to have natural gas ran to the house and I’d like to make use of our old fireplace. In the past, we had a wood stove but were wanting to look into the gas side of things. We are looking at inserts that fit directly into an existing small masonry fireplace that vent and draw fresh air from up the chimney (I think that’s still direct vent… correct me if I’m wrong). We are wondering how effective they are at heating during a power outage when the blower can’t be used. Out house is about 1000 square feet but we wouldn’t NEED to heat the entire thing. Also, are there any makes and models y’all prefer? Thanks!

 

[DAKSY]

Yes, the unit with a double liner is a DV appliance. If the power goes out & you either have a standing pilot or an IPI (Intermittent Pilot Ignition) System, with a battery back up, you will still get a decent amount of radiant heat from the unit. That effectiveness of that heat will be dictated by the both the BTU rating of the unit & the area of the room the unit is located in. If you close doors to adjoining rooms, the room with the appliance will be the warmest. With those doors open, that heat will gradually radiate outwards, but slowly without the blower operating. For 1000 sf in a well insulated home, you may be able to get by with a 30k - 40k unit. The size of your fireplace opening may also dictate the availability of a higher BTU rated unit. There are a number of quality units out there, but of the ones I have experience with, I prefer Regency or Heat & Glo.
Hope this helps…

 

[lethal dose]

Thanks for the follow up, DAKSY. My fireplace opening is 25" across the back, 29" across the front, 24" high, 16" deep... so quite small. I looked at some regency models but looks like I’m stuck in that 20,000-25,000 btu range. I should also ask… is pulling fresh air from outside best? I see some “b” vent options labeled as direct vent, but aren’t these using room air for combustion? I think I’d like to avoid that if I can still get a decent insert to heat and work with my masonry chimney.

 

[DAKSY]

Pulling combustion air from the exterior of the home via a co-linear or co-axial pipe is Direct Vent. B-Vent uses combustion air from inside the home. This can lead to cold drafts of air from the outside, as the combustion air being used needs to be replaced so it is drawn from the outside thru whatever openings in the house envelope it can find…

 

[stovelark]

The 16" depth is your limiting factor... Enviro E30 (28K on LP) might be a good choice too, you can order surround/slim face with a custom return of 3/4" and that would work. Kozy Heat's Chaska 29-L (IPI model) would be 30K LP but width needed is 29.5 in, I'm sure there is others that will work. You might be able to modify the opening width/depth to accommodate others? Good luck.

 

[Whitenuckler]

Hey! Looking to have natural gas ran to the house and I’d like to make use of our old fireplace. In the past, we had a wood stove but were wanting to look into the gas side of things. We are looking at inserts that fit directly into an existing small masonry fireplace that vent and draw fresh air from up the chimney (I think that’s still direct vent… correct me if I’m wrong). We are wondering how effective they are at heating during a power outage when the blower can’t be used. Out house is about 1000 square feet but we wouldn’t NEED to heat the entire thing. Also, are there any makes and models y’all prefer? Thanks!

If you are getting one with a 120V control circuit, you might be able to disconnect the normal source (unplug it)and plug into a UPS system.
I did most of the install of a Napoleon Direct vent NG fireplace. It used 120V for on-demand ignition and the blower. It had a battery pack for backup, but that would not run the blowers. You get way more heat out of them with the room blower. It also keeps them running cooler ie the air coming out does not get as hot. You need to be careful on the clearances to wood above the fireplace. If you have a basement below and can run a 14/2 cable in from below, and get at the other end at a junction box that would be ideal to use a 120V backup.