Greenhouse growers I need advice

[Bob in Albany N.Y.]

Here is the problem. I have a attached 17 by 25 greenhouse. We have an oil fired furnace from the house that heats the greenhouse. In other words it is just a second zone from my furnace. The heat is controled with a programable thermostat. I don't need anything fancy I just want it to adjust between the day and night temp. The problem is that there is just a normal programable thermostat in there that keeps getting ruined I assume due to the high humidity. I put new batteries in it and it works for a few days then it starts flashing low batteries and stops working. Naturally, I've tried new batteries. I also changed the whole thing out. Problem is they don't last long at all. The last one only lasted 6 months. That is just crazy. I just went on a two week vacation. Before leaving I changed the batteries. While I was away the alarm company called and said the greenhouse was registering too cold. I got my neighbor to go over and put new batteries in it. When I got home a week later is was already flashing low batteries. Donna changed out the thermostat and now all is working well.

So, what brand and model of a thermostate are you guys using in your greenhouses?

I tried looking on the internet but must not be using the correct search words. Now mind you I'm not looking for one of those inaccurate thermosate that have a large coil. Nor am I looking for one that you have to plug a electric heater in. Just a regular old programable thermostat that in rated for the humidity of the greenhouse. If you could direct me to a site that carries the product it would be even better. I'm just getting frustrated.

Thanks for any and all help

 

[NYEric]

Bob, I don't have a greenhouse but isn't there a mechanical thermostat that works on a coil and mercury contact?

 

[goldenrose]

Yes this is a problem with GH. I've had similar troubles that you described. I have a Honeywell PRO TH4000, it's been in the GH for a year now without incident. I believe it ran about $80? (You know the memory thing after a certain age!) Last year at this time when I got a new furnace, I put the thermostat in the driest corner rather than the middle of the GH. The furnace is mounted under the bench in the same back corner. There is a small fan on the lower shelf across the aisle that is blowing air constantly in that corner, is that what helps make the difference? This Honeywell will most likely be a back up thermostat. Last week my husband came home with a Robertshaw 9600, cost $40. The feature that attracted him to this one was if it should fail, it maintains a minimum temp of 40. Wouldn't that be nice if we could set that a bit higher?! His hope was that at 40, I wouldn't lose everything!

 

[gonewild]

If you want a dependable thermostat for a greenhouse you need to get one that is designed to survive in the moisture.

Here are some that should work fine.... Thermostats

Actually the old fashioned ones with the big external coil were very accurate and dependable. I don't remember the brand but mine used to get soaked all the time and just kept on working.

 

[gotsomerice]

I agree with gonewild. I would not use any thermostat that is using batteries. These battery-operated thermostats are not reliable. You might have to invest in the best thermostat. If you think about it, I am sure that a plant in you green house can buy a few thermostats!

 

[Bob in Albany N.Y.]

Gonewild, I may be missing something but I still couldn't find one of those thermastats that would automaticly change the day and night temp. Indeed, cost is not a factor here.

gotsomerice - Reliability is the name of the game. All the thermostats that are programable that I found are for home use not greenhouse. I'm sure I'm not the only one with this problem. Someone out there must have one that will fill my simple needs. I wouldn't even mind hiring an electrian if need be. I just need to find the right product for my needs. Remember I'm not plugs a electric heater into the thermosatat. This is a seperate zone off of my boiler.

 

[Candace]

Bob, is it possible you're hitting it with water instead of it being a humidity issue? I've never had a thermostat die from humidity in my g.h. But I could see it rusting out if it got hit with water frequently or dripped on by condensation. Have you tried relocating it somewhere else?

I've got several thermostats that take care of different systems. My heater runs off of a Home Depot home thermostat with the day/night differential you're talking about. It's a battery operated one as I wanted it for the simple fact that if there's a power outage, I want my heater to work(my heater doesn't need electricity and natural gas, as it's pilot light driven). I've had the thermostat for several years and have never had any problems. This is why I'm questioning if it's really your humidity that's the problem. What is your rh percentage?

 

[GROWINHYDRO.COM]

Bob,

You should visit the ACF Greenhouse website. I bought my greenhouse, heater, well...about everything but my swamp cooler from them. A+ Customer service, I mean top notch! Took care of every problem I had or product that failed, even if it wasn't their product.

They have tons of climate controllers, and you will find a few day and night thermostats as well as programmable ones.

http://www.littlegreenhouse.com/accessory/controls.shtml

I use the ACF Weatherproof Heating / Cooling - Single Stage Thermostat on the heater. The Dayton Adjustable Heating / Cooling Thermostat for my swamp cooler, and the Repeat Cycle Timer on the misting system and never had a problem (knock on wood) And I hose down everything so I know I have gotten them wet if not soaked.

Kind regards,
Jesse

 

[gonewild]

This is a seperate zone off of my boiler.

What does your thermostat control to get the heat into the ghse from the boiler?

 

[Candace]

Jesse, they do sell a lot of thermostats, but all require electricity to operate. Which can be a big deterrant for people who need to run their heaters during power outages. I don't know about Bob's needs, but one of my requirements is that is can't rely on electricity.

 

[GROWINHYDRO.COM]

Ah, sorry...I had electric in my head cause that's what I have, and a generator backup. I wasn't thinking gas...

This one looks like it would be a good redundant controller http://www.greenhousekits.com/resources/D4805-ACF-PSP300-Ins.pdf

 

[Bob in Albany N.Y.]

I'm using oil as a fuel to power the main furnace which is forces the hot water threw the pipes to warm the house and g.h.. I don't really need the batteries as when the power goes down I have a guardian generator that comes on with 5 seconds and powers most of the things in the house. It's no diffrent that having a zone for your down stairs and a zone for your upstairs. My one zone in both upstairs and downstairs combined and the second zone is the greenhouse. All the thermometer does is that it tell the furnace to turn on and send the heat.

 

[gonewild]

What does the thermostat turn on to send the heat to the ghse zone?

Is the hot water sent to the ghse by opening a solenoid valve?

 

[gonewild]

Heres one that might work......... Growstat

 

[gonewild]

This one does exactly what you want.... GrowMate

 

[GaryB]

Southern Burner makes a setback thermostat for about $115, that may work with your heating system. It does use batteries, but since it is may for greenhouse environments, it may work fine.

Here are a couple for units for around $100

IGS-021 Day / Night Thermostat with Remote Sensor