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8 forms of capital active hope agroecology agroforestry alder buckthorn Amazon anxiety apples arthritis back yard beans Bec Hellouin beech tree bees beneficial berries biochar biodigester biodiversity blackberries blackthorn book review brain brassica cage budget build building campesino capital card deck Celtic festivals change changes chemical-free chickens christmas circular clay pot cleansers cleansing milks climate change climate emergency climate grief climate solutions climbers climbing cob comfrey community compost compost teas connection consciousness conservation container cooking coppice coppicing cordial cosmology courgettes crafts crisis crop protection Cross Quarter Festival cultural emergence culture cycles degraded design diary diversity DIY do it yourself dryland earth care Earth's energy ecoculture economics ecopoetry ecosystem ecosystem restoration camps ecosystems edges edible edible flowers education efficiency elder elderflowers elements elixir energy equinox ethics face mask fair shares Fairtrade farming feedback feminine ferns figs film firewood flower essence flowers food food forest food garden footbath forage foraging forest garden forest gardening forests fruit fruit leather fruit trees fungi future future care gardening garlic gift economy gin Give Nature a voice Glennie Kindred global poverty glut grapes greenhouse grief groundcover grow grow food grow your own growing guilds habitat habits handcream harvest harvests hawthorn hazel hazelnut healing shrubs healing trees health healthy soil heart health hedgerow hedging herbal herbal remedies herbal teas herbalist herbs holistic holistic planned grazing home homeless homemade wine homestead hope Hugelkultur humanure hummus hungry gap IBC tanks Imbolc incense increase yields Indigenous inexpensive influence inspiration International Womens Day jam keyline kitchen garden lacto-fermentation Lammas land landscape landscapes life lifestyle limeflowers livelihood livestock living labs logs lotion low cost low-impact Lush Spring Prize macerations Mangwende Orphan Care Trust market garden market gardening marmalade marshmallow mass heater meadowsweet medicinal microbes microfarm mimic mindset mitigation money moringa Mother Earth mulch multifunctional mushrooms native plants natural natural building natural fertiliser natural skincare natural swimming pool nature nature connection nitrogen no dig no waste no-dig November nutrition nuts observe oca October off-grid oil cleansing orchard orchards organic organic gardening outdoor shower oven oxymel oyster pallets pasture-fed patterns people people care peoplecare perennials permaculture permaculture design permaculture magazine award permaculutre permayouth pesto pests philippines pine tree pips pizza oven plant profile plants pollinators pollution polyculture polycultures preserving principles propagating protection pruning prunings psycho-spiritual awareness psychospiritual transformation rainforest rainwater raspberries recipe recipes reduce reed beds regeneration regenerative regenerative agriculture relative location relative matter remedy renewable renewable energy resources restoration reuse revolution rhythms rootstock rootstocks roundhouse roundwood runner beans sage salad salve Samhain schools Scotland scotts pine seasonal seasons seeds selfcare Sepp Holzer september septic tanks sewage treatment shade sheet mulching shrubs skincare sloes slugs small solutions small-scale smallholding social justice soil health solar solutions sowing spiritual spring squash stacking functions stock-free straw straw bale summer sustainable Sweet Bay syntropic systems temperate terraces thistles thrutopia timber timber framing tincture tonic toolkit tools transformation trees upcycle urban veg garden vegan veganic vermicomposting vinegar walnuts waste water water cleansing watering weeds wellbeing wetland wild edges wild food wild garlic wildflower wildlife wine recipes wings winter winter greens winter salads wood stove woodburner woodland woodland management woodlands worms yarrow year-round food yield young people youth zai pits zone 00 zoning

Topics

8 forms of capital active hope agroecology agroforestry alder buckthorn Amazon anxiety apples arthritis back yard beans Bec Hellouin beech tree bees beneficial berries biochar biodigester biodiversity blackberries blackthorn book review brain brassica cage budget build building campesino capital card deck Celtic festivals change changes chemical-free chickens christmas circular clay pot cleansers cleansing milks climate change climate emergency climate grief climate solutions climbers climbing cob comfrey community compost compost teas connection consciousness conservation container cooking coppice coppicing cordial cosmology courgettes crafts crisis crop protection Cross Quarter Festival cultural emergence culture cycles degraded design diary diversity DIY do it yourself dryland earth care Earth's energy ecoculture economics ecopoetry ecosystem ecosystem restoration camps ecosystems edges edible edible flowers education efficiency elder elderflowers elements elixir energy equinox ethics face mask fair shares Fairtrade farming feedback feminine ferns figs film firewood flower essence flowers food food forest food garden footbath forage foraging forest garden forest gardening forests fruit fruit leather fruit trees fungi future future care gardening garlic gift economy gin Give Nature a voice Glennie Kindred global poverty glut grapes greenhouse grief groundcover grow grow food grow your own growing guilds habitat habits handcream harvest harvests hawthorn hazel hazelnut healing shrubs healing trees health healthy soil heart health hedgerow hedging herbal herbal remedies herbal teas herbalist herbs holistic holistic planned grazing home homeless homemade wine homestead hope Hugelkultur humanure hummus hungry gap IBC tanks Imbolc incense increase yields Indigenous inexpensive influence inspiration International Womens Day jam keyline kitchen garden lacto-fermentation Lammas land landscape landscapes life lifestyle limeflowers livelihood livestock living labs logs lotion low cost low-impact Lush Spring Prize macerations Mangwende Orphan Care Trust market garden market gardening marmalade marshmallow mass heater meadowsweet medicinal microbes microfarm mimic mindset mitigation money moringa Mother Earth mulch multifunctional mushrooms native plants natural natural building natural fertiliser natural skincare natural swimming pool nature nature connection nitrogen no dig no waste no-dig November nutrition nuts observe oca October off-grid oil cleansing orchard orchards organic organic gardening outdoor shower oven oxymel oyster pallets pasture-fed patterns people people care peoplecare perennials permaculture permaculture design permaculture magazine award permaculutre permayouth pesto pests philippines pine tree pips pizza oven plant profile plants pollinators pollution polyculture polycultures preserving principles propagating protection pruning prunings psycho-spiritual awareness psychospiritual transformation rainforest rainwater raspberries recipe recipes reduce reed beds regeneration regenerative regenerative agriculture relative location relative matter remedy renewable renewable energy resources restoration reuse revolution rhythms rootstock rootstocks roundhouse roundwood runner beans sage salad salve Samhain schools Scotland scotts pine seasonal seasons seeds selfcare Sepp Holzer september septic tanks sewage treatment shade sheet mulching shrubs skincare sloes slugs small solutions small-scale smallholding social justice soil health solar solutions sowing spiritual spring squash stacking functions stock-free straw straw bale summer sustainable Sweet Bay syntropic systems temperate terraces thistles thrutopia timber timber framing tincture tonic toolkit tools transformation trees upcycle urban veg garden vegan veganic vermicomposting vinegar walnuts waste water water cleansing watering weeds wellbeing wetland wild edges wild food wild garlic wildflower wildlife wine recipes wings winter winter greens winter salads wood stove woodburner woodland woodland management woodlands worms yarrow year-round food yield young people youth zai pits zone 00 zoning

Turning a Wood Stove into a Mass Heater to Warm a Greenhouse

Even when there's snow outside, this greenhouse still has tomatoes and peppers growing. Max Edleson explains how to make an old wood stove into a mass heater, prolonging the growing season!

Kiko Denzer and I were hired to build a heater in a greenhouse for some very avid gardeners. They had experimented with using a wood stove but there simply wasn’t enough heat retained for the stove to heat the greenhouse from one day to the next throughout the winter. Our task was to incorporate the old wood stove, mostly taking advantage of the glass door and firebox it offered, and plug it into a system with channels and enough mass to absorb sufficient warmth to heat the greenhouse with one firing a day. This article chronicles that build and the results.

Here you can see the long path that the smoke makes through the bench after it has exited the original stove. All of the heat retained by the bench would have otherwise gone straight up the chimney. There is a bi-pass damper which acts as a valve and allows for a straight shot to the chimney when you are making a cold start.

Visiting in the winter time

The following photos were taken on December 3rd 2012 in the Willamette Valley of Oregon. You can see tomato and pepper plants maturing inside the greenhouse while the ground outside is covered in snow.

Step-by-step photos of the construction process

Dry lay-out. I had carefully drawn out the heater and we had poured the pad to planned dimensions… but it is always still important to check that everything fits together as planned.

The original wood stove that inspired the project. I used a 4 x 1/2inch grinder with a metal cutting disk to cut out the baffle shelf it had inside.

We laid up as many courses as we could behind the wood stove before moving it into place because we knew we wouldn’t be able to get there to work once it was there.

Now we have placed the wood stove which will act as our fire box. We are examining how the linteled course will go.

You can see in this picture and the subsequent one that we have wrapped the stove in 1 inch ceramic wool blanket. This is both to ensure that the metal stove has adequate room to expand and contract within its new brick housing and also to raise temperatures in the firebox which will contribute to a cleaner burn. In this photo, we are beginning to fully enclose the stove with brick and beginning to define the down and up-draft channels that will enter into and leave the bench.

A cleanout was installed at the bottom of the downdraft (the square box bottom left). We are using a soot door by Pisla and a masonry frame that surrounds it.

Detail of first flue liner plugging into brick work. We used ceramic wool to help seal the union while giving the two different materials room to move when heated. The flue tiles are mortared to each other but very minimally mortared to the bench surround.

The next couple of photos show us marking a flue liner for an angle cut using water in a wheel barrow to give us a mark all around the shape. Each bringing the flue liner down to our marks.

Working out the corners and also inserting the copper heat exchanger that Ed had made to warm water up for watering starts and seedlings.

Flue liner assembly is completed. Cleanouts at end of bench to access both horizontal runs. Framing up and reenforcing the concrete pad which will act as the bench top.

This is an important photo which shows the basic design. You can see the firebox and the bell that will be formed above it, and the down and up-draft channels. The heater has been designed around the size of the brick units to minimize cuts and complexity.

The bi-pass damper is put into place. When open, it gives the flue gases a direct shot up the chimney.

We have used slabs made of castable refractory to cap off the ‘bell’ above the firebox and the entrance into the downdraft. An anchor plate with a shut-off damper has been installed for the chimney to plug into.

The heater is near completion.

To read the full article with more photos visit www.handprintpress.com/featured/greenhouse-heater

Further Resources

Watch

Living with the Land: Off-grid Living

Books

The Permaculture Book of DIY
by John Adams and friends

Articles

How to Make an Outdoor Brick Oven from Recycled Materials

About the Author

Max is a builder, craftsperson and musician and his services include building masonry heaters, wood-fired bake ovens, round-pole carpentry, and website design.