Question on direct vent fireplaces
I am gut renovating and expanding a circa 1920 cottage. I am trying to get as close to net zero as I can. I am an architect fairly well-versed in the principles and techniques of net-zero, DER and Passivhaus my firm having designed and built two Passivhaus and 13 net zero homes, all of which have had their performance measured and verified. The point of this bragg-y credentializing is to head off the inevitable finger wagging that usually comes upon mention of the very idea of including a fireplace in a home that aspires to net zero. I get it. Not a good idea. Point is, I know it is not a good idea to have a fireplace of any type if you’re primary goal is energy efficiency and indoor air quality. But for several reasons – one of which I am married to – its gonna happen. So my simple question is this: Are there any specific brands and models of direct vent, sealed combustion, gas fireplace units that folks have experience with to look for or to avoid from the standpoint of infiltration or exfiltration, and are there any techniques – besides the obvious air sealing measures – that others have taken to ensure they are not an energy suck and a health hazard?
I feel this question has broad relevance because although a wider and wider swath of the home buying public cares about energy efficiency, they balk at being told they simply can’t have things they want. Most of my clients want a fireplace. As further proof, a quick perusal of Houzz will show you that very few living rooms do not have a fireplace as their focal point. So its a problem to solve for all of us, even if some of us think the very idea is silly, if not morally wrong. 🙂
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
What style are you looking for? Craftsman cottage-y, farmhouse, transitional, traditional, or something else? Would your wife access an electric fireplace that looked and performed (mostly) like a traditional wood burner?
I'll be curious to read the responses since I may have to do something similar in my next house. I too have a in-house chief designer to content with.
I think it can range from transitional to contemporary, ie: one of the linear ones may be ok, but in any case it needs to be "clean" looking. I don't know enough about the electric ones to say if it would pass muster - it was actually not easy to get her to sealed, glass fired from wood. So I'm doubting I could get her - or me- that far.
Majestic seems to strike a nice balance between style and cost with this one: http://www.majesticproducts.com/Products/Jade-Series-Direct-Vent-Gas-Fireplace.aspx
Are you considering other gas appliances? If you are going to be saddled with the year-round connection cost, you might want to install a gas furnace and water heater, for example. Of course, that really bumps up your carbon footprint.
Thanks Steve. No, I’m not going to use gas appliances anywhere else- for energy efficiency and indoor air quality reasons. The whole system will be electric to take advantage of photovoltaics I am able to install., I’ll have a dedicated propane tank (no gas service where I live) for the direct vent fireplace.. My question has less I do with style than quality as it pertains to air seal-ability. And best practice. I’m going to a lot of effort and expense to make a super efficient and well-sealed envelope - I just want to make sure when I violate that envelope with a fireplace I do it with the best unit in the least leaky way.
As a 100% ZERH Designer, I've started to design all homes with electric fireplaces, as we can run it with on-site production/battery/net-metering. I've been specifying Napoleons, as I think they have a good product and reasonably priced. Best part, no chases to build or air-seal.
Along with heat pumps, and induction cooktops, there are no reasons to run gas into the house.
Armando,
Thank you very much - I’ll look more closely at electric units.
I have direct vent fireplaces... and the one piece of advice I can suggest is that you make sure that if its NG, that it doesn't have a standing pilot. If its a wood burner of some time... make sure the system is designed to draft without a lot of extra fiddling... and/or you understand how much power the fans for generating the draft might use.
A NG with a standing pilot can add a lot of heat back into the house during the summer time when you are using AC. NG fireplaces with electronic ignition are available - but you can't generally retrofit a fireplace that used a standing pilot and convert it into an electronic ignition.
And our house... a 60's house with recessed lighting (retrofitted with in-contact, air tiight cans) and the two NG fireplace inserts into the prior log fireplaces. Blower door tested at 2.8ACH50 before any additional air sealing work was done.
A direct vent fireplace can also provide a nice source of heat during power outages. If you don't want to pay the monthly cost of NG, you might want to consider propane or even gel if you don't plan to use it very often.
Armando,
The Napoleon looks very nice. Thanks for mentioning it.
Y'all welcome. I forgot to mention another upside, no penetrations on the building envelope to worry about.