How can I make my fireplace more efficient?

Thank you for reading my post! I am blown away by the knowledge, creativity, and experience of the people who post here. I have a lot of experience with gardening and water conservation, but this RMH stuff goes over my head. I believe I have a fairly typical setup but would really appreciate some guidance on how to get stated. Please allow me to explain my situation below.

I lucky enough to live in a single family house on a south facing slope in zone 10a Oakland, California. In the home there is a fireplace that I would like to use as I have access to free firewood (but not a huge amount). I have heard that open fires are wasteful and polluting. Wood stoves seem to be a step up, is it possible to put one in my fireplace? Just stick it in there and light a fire? If there are any other systems that may work well for me, I'd love to hear it. I can tackle complex piping projects as I am a ua trade school instructor. I'd love to keep costs low but have it look decent. Really appreciate any suggestions. Thank you so much.

Hi Gavin, welcome to Permies! You could certainly install a fireplace insert, which is a wood stove that is designed to be put into a fireplace. But there are a few more options.

If you want to keep the open fire, you could retrofit it into a Rumford fireplace. Those are shallower than normal fireplaces and reflect heat out into the room better.

If you want to get into rocket heaters, but don't want to build one from scratch, you could buy a Liberator Rocket Heater from the factory in Missouri.

Of course budget is everything.  Given your location, I suspect heating is not a major concern…..as compared to Iowa. The insert would be relatively inexpensive and easy.  The Rumford is a great idea but would probably involve more money.  A third option is a wood burning cookstove.  I am eying the Concept 2 at Lehman’s.  Do take careful measurements to be sure the stove will connect with your fireplace if you go this route.

Another idea might be to just add mass to the existing fireplace.

My idea would be to buy some firebricks and mortar.

Then line the existing fireplace with the firebricks and mortar.

Standard firewood is 16" so you could continue to line the fireplace with fire brick down to maybe 20".

Here are a couple of threads that might offer some other suggestions:

https://permies.com/t/162124/Retrofit-masonry-fireplace-rocket-mass

https://permies.com/t/72030/Affordable-add-mass-existing-woodstove

Welcome aboard!  Before using it, I’d try to get access to an inspection camera and take a look a the chimney to make sure it is in good shape.  Assuming it is, try it as is before you change anything.  My experience with fireplaces is that they make the room they are in fairly comfortable via radiant heat, but draw too much air, cooling the peripheral rooms.  With a south facing home in 10a, you may just want an occasional fire for ambiance and to take the chill off of your living area.  Your bedrooms might be fine with heavy bedding on cool nights.  As far as clean burning and efficiency goes, try to split your wood a year ahead and keep it under cover.  With limited rainfall in Oakland, it will be tempting to leave your wood uncovered, but the drier it is the better.  

If you come to decide that the fireplace is not adequate, you can use an insert or a freestanding woodstove installed slightly in front of the fireplace, assuming you can get adequate clearance from mantles, furnishings etc.  You didn’t mention the size of the home, how well insulated, quality of the windows, or other heating factors, but in your climate, a small catalytic woodstove or insert, would probably provide plenty of heat for the entire home.  And no, you can’t just put one in the fireplace, it must be ducted through the existing chimney.  Check into your local codes and insurance requirements.  Also be sure to have a CO detector(s) and a smoke detector(s) in your home.

Heating your home with wood is a very rewarding experience, but certainly takes some care.  Do your research, and enjoy!

Thank you everyone for all the suggestions! Given my climate and budget I will probably go with a fireplace insert. I found one for free nearby on Craigslist. The wood burning cookstove is very interesting to me though, I'd love to cook on a wood stove.

caveat to the recommendations above:

A woodstove is a good option for your location. You have plenty of room to fit one. Typically these need a metal flue ducted through the existing chimney, and getting these installed tend to be about half the cost of the installation. Most home insurance will insist on it being installed by a certified professional, as if done poorly there is a large fire risk. Most flue pipes are double skin insulated - the intention is to ensure the temp stays high in the flue for good draft and to reduce creosote formation on the cold metal. They need to be sized appropriately for the stove, and there are restrictions on layout (bends, constrictions, height of chimney etc..) to observe to get a stove that operates well.


An insert will definitely be a meaningful upgrade for you - both in terms of heat produced, and cleanness of burn. But you can't just shove it in the gap and crack on.

You could install a fireplace insert to turn your open fireplace into a more efficient wood stove. It’s a cost-effective solution that improves heat output and reduces pollution. Just make sure to get a chimney liner for proper ventilation.