Tagged: heating greenhouse

greenhouse ventilation

Greenhouse Ventilation

Greenhouse Ventilation 

Vents VS Exhaust/Shutter System

greenhouse ventilation

There are many factors to consider when greenhouse shopping; Insulation, glazing material, space, foundation, heat and of course greenhouse ventilation. And if you are planning on growing year round you want to make sure to choose the most energy efficient structure because heating in the cooler months can be expensive – This is where great insulation can reduce energy costs.

greenhouse ventilation
Example of roof vent
Greenhouse ventilation
Example of roll up sides

Manual or automatic roof vents have their advantages and disadvantages. If the greenhouse is designed very well then aerodynamics have been considered and the roof vents will be placed in the perfect position for wind to pull air out while still circulating air through the greenhouse. Placement of the greenhouse is also very important for wind to catch on the ridge of the greenhouse and create a vacuum type air movement. A large circulation fan or multiple fans will be required in the interior of the greenhouse and will aid in fresh air exchange. Some larger or commercial greenhouses offer a roll up design that allows for the sides of the greenhouse to be completely open to the outside. Now, if you are concerned about pests this might not be the best option for you because generally with open air vents many of them are needed and screening them can be difficult, if not impossible. Maintenance can give you trouble as well. If you do not have the time to go open the manual vents, do not have the ability to climb a ladder for high roof vents, or have limited budget for automatic vents then an alternative option should be considered. For a very small/beginner greenhouse or a small lean-to style with a low insulation value these type of vents are appropriate. The higher the insulation value of the greenhouse glazing material the stronger ventilation you will need.

 

greenhouse ventilation
220V power panel

Thermostatically controlled ventilation is very popular and with supplemental air circulation can be most efficient. Sunglo uses exhausts fans and motorized intake shutters controlled by a thermostat with the option to hook up to a heater as well; we call them power panels and include other electrical items too. So if you prefer your greenhouse to remain between 50° and 75° all you have to do is set the thermostats for the ventilation and heater to turn on and off automatically. The exhaust fan and shutter are synchronized to open at the same time. The motorized shutter opens to allow fresh cool air into the greenhouse while the exhaust fan starts to spin and expel the used hot air that has risen inside the greenhouse. Sunglo’s basic system is rated to exchange fresh air throughout the greenhouse once per minute; providing you with a system that cools rapidly. The basic system is included with every Sunglo greenhouse. The exhaust fan(s) are placed as high as possible on one end of the greenhouse and the

greenhouse ventilation
Schaefer exhaust fan and shutter
Greenhouse ventilation - Automatic opener
Automatic vent opener for Sunglo vent

shutter(s) are placed as low as possible on the opposite end. This allows for the best possible circulation throughout the entire greenhouse. There are many brands to choose from but either aluminum, steel, poly or fiberglass options are available each with different pros, cons, sizes and pricing. We include poly exhaust fans and shutters with our greenhouses but any type is available for upgrade. Automatic vent openers are available for the gable end manual vents on our greenhouses and will increase air circulation as well. They do not use any electricity. These automatic openers are controlled by a wax piston. By twisting the piston left or right sets the degree to which it opens. These automatic openers are specially important in areas where the climate stays consistently at or over 80 degrees. By setting up a circulation fan inside the greenhouse and setting the automatic openers to open before the ventilation system starts will save you electricity usage. Sunglo also offers a variety of atmospheric controls. If you would like to view some of the ventilation products Sunglo offers please visit the Schaefer website or give us a call with your inquiry.

 

greenhouse ventilation
Sunglo greenhouse – Front with intake shutter and back with exhaust fan

Learn more about summer climate control here.

If you are interested in adding ventilation to your greenhouse or would like to discuss options or have questions about anything please give us a call at 425-251-8005 or e-mail to info@sunglogreenhouses.com.

2100 Series (15’3″ Width) Sunglo DIY Greenhouse

 

1200 Series (10’3″ Width) Sunglo DIY Greenhouse

 

1000 Series (7’9″ Width) Sunglo DIY Greenhouse

 

Sunglo Surface Area Guide

Sunglo Greenhouses Surface Areas-

This post is a supplement of a previous post for determining the heating or BTU requirements of your greenhouse – Click here to read the Greenhouse Heating post.

The following are approximate surface area’s of each Sunglo greenhouse series.

1000 Series - Surface Area

  • 1000 Series – 7′ 9″ Width

Model                Surface Area

7.5ft – B                     228

10ft – C                      276

12.5ft – D                   324

15ft – E                      372

17.5ft – F                   420

For every 2.5ft after model 1000F add 48 to the surface area.

1200 Series - Surface Area

  •  1200 Series – 10′ 3″ Width

Model                Surface Area

10ft – C                       338

12.5ft – D                    392

15ft – E                       446

17.5ft – F                    500

20ft – G                       554

For every 2.5ft after model 1200G add 54 to the surface area.

2100 Series - Surface Area

  • 2100 Series – 15′ 3″ Width

Model                Surface Area

10ft – C                     484

12.5ft – D                  549

15ft – E                     614

17.5ft – F                  679

20ft – G                    744

For every 2.5ft after model 2100G add 65 to the surface area.

1500 Series - Surface Area

  • 1500 Lean-To Series – 5′ 1.5″ Width

Model               Surface Area

10ft – C                    169

12.5ft – D                 196

15ft – E                     223

17.5ft – F                  250

20ft – G                    277

For every 2.5ft after model 1500G add 27 to the surface area.

1700 Series - SUrface Area

  • 1700 Lean-To Series – 7′ 7.5″ Width

Model                Surface Area

10ft – C                    242

12.5ft – D                 275

15ft – E                    307

17.5ft – F                 340

20ft – G                    372

For every 2.5ft after model 1700G add 33 to the surface area.

If you are a customer with a custom style Sunglo or have a discontinued series or just have questions please give us a call at 1-800-647-0606.

Overwintering in the Greenhouse

greenhouse snow loadOne of the things I enjoy most about spring is planning out my gardens for the season. However, it also used to be one of things I dreaded as I began to tally up the cost of buying new plants every year. Having a greenhouse has allowed me to overwinter all of my beloved container plantings, and some of my garden perennials that cannot survive the winters here in the northwest. I have put a great deal of time into designing and caring for the container arrangements around my house, and now I do not have to park in the driveway during the winter while I store them in the garage.

pot in potLast year I started using a pot in pot system where I buried larger pots in the garden that the perennials’ pots can fit into. This makes pulling them in the fall much less labor intensive and then in the spring I just put them back into their prearranged spot and cover both pots over with mulch. This has also allowed me to incorporate rare plants that are not recommended for my hardiness zone into my landscape. I know pride is a sin, but it is always satisfying when someone says, “How did you get that to survive? I tried and it didn’t make it through the first winter.”

Then I proceed to tell them about how my greenhouse has allowed me to really take my gardening to the next level. I opted to get the all season package that included a heater, motorized intake shutter, exhaust fan, and all the thermostats to automatically control them at the temperatures I set. To ice the cake it also came with a wireless weather station that allows me to monitor the temperature and humidity of the greenhouse from my kitchen. All I have to do is check periodically to make sure the pots do not get bone dry and the climate controls do the rest. I do not have to worry about pesky rodents, freezing, fluctuations in soil temperature, or dessication from being exposed to cold dry air because my plants are protected within the greenhouse.

Sunglo in AlaskaThere are only a couple of things to keep in mind when you set out to overwinter your plants in a greenhouse. In the early fall, I gradually reduce watering and fertilization and allow the plants to harden off outside until just before the first frost.This puts them into a state of dormancy and keeping the greenhouse temperatures between 45° and 55° F throughout the winter prevents them from coming out of it prematurely.This is very important because any undesired growth at such low temperatures will more than likely be weak and therefore highly susceptible to various infestations.

overwinter greenhouseThis is where a Sunglo greenhouse truly outperforms the competition. The exhaust fan, motorized intake shutter, and heater, all controlled by individual thermostats, ensure that the temperatures stay within the desired range. Most hobbyist greenhouses on the market use a paraffin wax piston to automatically open a vent of some sort. It is impossible for this type of passive ventilation system to maintain temperatures between a specified range.

sunglo snow loadDuring dormancy water uptake is dramatically reduced, but you must be careful not to let the soil get to dry. Just a slight dampness to the touch is sufficient. I considered installing a drip watering system on an irrigation timer this year, but decided against it. Colder temperatures and overly wet soil can spell certain doom for roots and the plants that depend on them. Instead I will continue to check them periodically and I suspect they appreciate the company.

overwintered plantsAs spring approaches I raise the temperature to between 55° and 65° F and gradually increase it from there. Some people prefer to keep the temperatures in that range until they move their plants out of the greenhouse to ensure they are hardened off. I have found that a strong oscillating fan and cooler night temperatures promotes strong enough growth for outdoor conditions. I also wait until I am absolutely certain there will be no more frost before I move anything out into the garden. I resume regular watering and begin an incremental fertilization schedule starting at half strength. By sometime in March I have the temperatures high enough to start spending some quality time in the greenhouse again and begin to germinate seeds, pot up the dormant cuttings I have taken over the winter, and get back into the business of what I love most.

I still enjoy planning out my gardens every spring, but with most of my plants all ready to go I now marvel at how much money I save. The question I am most asked is, “Isn’t the cost of heating the greenhouse throughout the winter more than the plants are worth?”  To which I always inwardly ask, “How do you put a value on keeping that which you love so much alive?” But in all honesty, being as serious a gardener as I am,  the unrivaled insulation of my Sunglo’s dual pane design keeps my energy costs well below what I used to spend on plant material every year. If you are interested in taking your gardening to the next level or have more questions related to overwintering please give us a call.