Glenn's Passive Aggressive Solar Heating

[glenn-k]

My wife is always calling me that and I think I finally found out what she was talking about...  the new heating system I made for her bedroom.

It is passive I think, because I am using the heat from the top of the greenhouse.  I recently read that all you need for a heat collector is a glass surface.  Yup -- I got a ton of them up there.  Average about 14'x34' of glass.  

I have been leaving it fairly open - never finished it but this year things are getting a bit more caught up so I decided to do a bit more with it.

A man on another site I was reading mentioned that he used a blower hooked to a couple of solar panels - sun comes up - motor goes on - no need for a thermostat- sun goes down - the motor goes off - no sun, the motor stays off.  In the summer I will disconnect it.  A friend gave me an old car heater blower and I had my two old original 50 watt solar panels - the rest of the system won't even miss them.



Next thing was to take the motor to the roof and see if the panels would run it.  Disconnected them from the system - changed them from series 24v to parallel for 12 volts.  Motor took off- no problem.  The motor -- that's the aggressive part of it--- it gets in there and gets the job done.   A good head of air too.



Next thing was to run down to the junk pile and find some suitable pipe.  I had some old  PSP thinwall 4" sewer pipe that was the perfect size to slip over the end of the blower output.  It was square - the pipe was round but it fit.  Then a good wrapping with duct tape --- Hey -- I even use the proper tool for the job.

It's a duct isn't it?

I found a "T" and a 45 to make my duct job perfect.  Next thing was where to put it.  If I put it to the top of the room I had to cut through the wall - no big deal but the heat would want to leave the room at night right back out the way it came in - so to the bottom it was.  The easiest place to go in was through the closet wall - the closet only has a curtain on it so this would work fine.  



This is experimental so I didn't want to spend a lot of time and money making it look real cute so This fast hookup will work fine for now.  

When we checked, room temp was 54 degrees - air coming in from the passive aggressive solar heater was 71 degrees.  It will get warmer as I seal the greenhouse up better.

I'll tell Sassy I'll make it all look better later -- that's what she wants to hear.  Is that Passive /Aggressive?

[Amanda_931]

Sounds good to me, but it might depend on if you whined about making it look better later.

[Bruce]

the ole greenhouse efect - I think I've heard of that  

[glenn-k]

Somebody's got to do it, eh? Bruce.

I was thinking that if this works, it would be a nice way to have a bit warmer bedroom without having to start a fire in the stove/fireplace over there.  It would just warm up by itself on any sunny day even if it was cold outside.  Who knows how far this thing could go if successful.

The bedroom is across the bridge at the end of the greatroom so we spend our day in the apartment area and it's a bit of a pain to start a fire over there too.

About 4 p.m. as the sun went low, the fan also went low and stopped blowing air into the room.

[Sassy]

Glenn said  

I'll tell Sassy I'll make it all look better later -- that's what she wants to hear.  Is that Passive /Aggressive?

Sounds good to me, but it might depend on if you whined about making it look better later.

I have to time my whining just right    Too much, the passive-agressive response sets in  

But I do think this should work pretty good - it was such a shame to let all that nice hot air go to waste  

[glenn-k]

Sassy mentioned that the fan was running when she went into the bed room.  

Report of current conditions:

10:43 AM Fan running at a good speed.  Room temperature from unheated night (the room-- not us) :-/ 52 degrees.  Air temp coming in from the Passive Aggressive system 82 degrees.

We have a raised stabilized adobe floor so if room temperature comes up I expect at least some stored heat available from it.

[Sassy]

you could also use this for cool tubes - the solar fan would turn on to pump cool air through the tube  

[glenn-k]

Sensors indicated that the prime mover was achieving undesirably high temperatures which were emanating from it's outer housing.   (I heard an engineer talk that way once.) :-/

Translation:  I stuck my hand under the plastic at the top of the strawbale insulation of the greenhouse and the motor felt a bit hot.  I assumed that it was because the motor had been wet in the past and may have had a bearing problem.

I quickly went to the junk pile and found another of the heaters my friend had given me.  I removed the heater core and plugged all openings that were not going to be used.



With self drilling fasteners I attached a piece of drain pipe of the proper size to connect to a piece of PSP.  



Wire stubs were attached so that the system would not be shut down for longer than about 5 minutes for the change.

In about 30 minutes I checked and the new blower was running a bit hot too.  Checking showed that the unit was pulling about 3.02 amps at 16.2 volts.  That was the problem.  

The two 50 watt solar panels in parallel were putting out too much power.  I guess it's time to go back up on the roof and remove one from the system.

Stay tuned for more updates.

Note: Incoming air temperature at this time was measured at 89 degrees F.  Room temp was up to 62.  Outside temp is 68F.

[glenn-k]

I removed 1 solar panel - currently running on one Siemens 12v 50 watt solar panel.

New voltage is 14.14 volts and room temperature was 64 degrees  Incoming air is now 86 degrees and OAT is 69 degrees F.  There is almost no noticeable difference in the speed the blower is running at.  With a 33 gallon trash bag my assistant, Sassy and I  measured fan output at one bag full in just under 4 seconds.  This works out to a little over 1 cu. ft. per second, or 60 cfm.  At this rate the room will get an air change every 40 minutes.  

What does this all mean?  I dunno. :-/

[Amanda_931]

I love the fancy measuring devices.

[glenn-k]

I'm right up there with Mr. Wizard.  In my defense I am using about a $150 clamp-on digital volt and amp meter.

[glenn-k]

This is now working so good I already forgot about it. :-/

Sassy said it was sitting in there running all by itself today with no help from anybody.

Pretty passive, eh?

[Amanda_931]

 

[desdawg]

Good job Glenn. I am going to have to find a forum that isn't this high tech only I can't find one.  :-/

[glenn-k]

We're high tech in a low tech way.

This thing works every day the sun shines and if it is running you can bet that the incoming air is at least 10 to 30 degrees warmer than the room.

Don't look too hard, desdawg -- we need you here.

[desdawg]

Actually I enjoy this forum too much to leave. I get exposure to ideas that I would have to work hard to find elsewhere. So I get the opportunity and motivation to learn new things which is much of what I am about. Kudos to all of the folks that make this forum what it is.

[glenn-k]

I think you are like me -- get bored doing the same thing all the time.   :-/

I guess that's why we have so much fun here trying out new things.

[glenn-k]

Passive Aggressive heater is still performing with no problem.  OAT is currently 37.4F   Solar heated air coming in is 63 degrees.  I still haven't finished sealing up the greenhouse.