Hot water in a tank to heat a basement apartment.

Hi all,

 First off, may apologies. I didn't know where to post this.  Also, I always try to do some research before I post so I don't post redundantly but I couldn't find anything.

I live in a basement apartment in Connecticut (Zone 6).  It's about 8400 cuft (30*40*7) of open studio space.  We have oil heat here with baseboard hydronic and I'm trying to reduce the oil bill and mostly, be warmer.  The thermostat hangs out around 60-62 during the day.  It's set at 55.  So naturally, it's about 62 down here.  66-67 is super comfortable down here.  I'm only looking for a Delta of about 4-7 degrees.

If you are familiar with David Poz on Youtube he did a comparison of PV vs. Solar Thermal a few years ago.  He uses both technologies to heat their respective 55 gallon barrels with about 50 gals of water in them.  For the PV he wires direct to a DC 48v 1500 watt water heater element. WIth direct wiring the heating element only gets powered when the panels are generating enough voltage to power the element.  Both of the barrels are outside in February behind his solar array.  He insulates both barrels with some foil faced insulation, I didn't catch the R value, sorry.  After a few days he's getting temps in the 150-160 range with the PV system.  Keep in mind, these are outdoors, in February in Massachuesetts.

Here's a link to one of the videos in the series he does about PV vs. Solar Thermal: https://www.youtube.com/watch?v=KVeGummoXS0&t=2s

My thoughts are this.  I basically want to do the same thing but the barrel will be inside.  I'm not going to insulate the barrel.  I might put a fan lightly blowing some of the heat that radiates from the barrel off of it.  The water temp should get  higher seeing the barrel is indoors.  I realize the barrel temp dips when there's less sun.

But am I wrong to think that this will raise the temp of my apartment?  I'm just trying to think this through.

Thanks in advance!

John

Couple of questions;
- What is a basement apartment
- What is delta
-  What temperature do you actually want?
- If the thermostat is set at 55, why is the room 62?

John C Daley wrote:Couple of questions;
- What is a basement apartment
- What is delta
-  What temperature do you actually want?
- If the thermostat is set at 55, why is the room 62?

John

It might be a slight language barrier here, I see you are from Australia. Do Australians call apartments "flats" like the British do?  A basement apartment is a flat in the lowest level of a single family home.  Built in the foundation of the home.  I hope that helps.

Delta is a fancy way of saying "change" or "difference",  commonly used in the sciences.  ex.  67-62=5; therefore the delta is 5.

I'd like the temp to be somewhere around 67 deg Faranheit

The room naturally stays a bit warmer due to it being embedded in the ground. The heat will come on if the temp drops below 55.  62 is bearable, but 67 is much more comfortable.  The goal is to be more comfortable.

Hope this helps!

j sigs wrote:Hi all,

 First off, may apologies. I didn't know where to post this.  Also, I always try to do some research before I post so I don't post redundantly but I couldn't find anything.

I live in a basement apartment in Connecticut (Zone 6).  It's about 8400 cuft (30*40*7) of open studio space.  We have oil heat here with baseboard hydronic and I'm trying to reduce the oil bill and mostly, be warmer.  The thermostat hangs out around 60-62 during the day.  It's set at 55.  So naturally, it's about 62 down here.  66-67 is super comfortable down here.  I'm only looking for a Delta of about 4-7 degrees.

If you are familiar with David Poz on Youtube he did a comparison of PV vs. Solar Thermal a few years ago.  He uses both technologies to heat their respective 55 gallon barrels with about 50 gals of water in them.  For the PV he wires direct to a DC 48v 1500 watt water heater element. WIth direct wiring the heating element only gets powered when the panels are generating enough voltage to power the element.  Both of the barrels are outside in February behind his solar array.  He insulates both barrels with some foil faced insulation, I didn't catch the R value, sorry.  After a few days he's getting temps in the 150-160 range with the PV system.  Keep in mind, these are outdoors, in February in Massachuesetts.

Here's a link to one of the videos in the series he does about PV vs. Solar Thermal: https://www.youtube.com/watch?v=KVeGummoXS0&t=2s

My thoughts are this.  I basically want to do the same thing but the barrel will be inside.  I'm not going to insulate the barrel.  I might put a fan lightly blowing some of the heat that radiates from the barrel off of it.  The water temp should get  higher seeing the barrel is indoors.  I realize the barrel temp dips when there's less sun.

But am I wrong to think that this will raise the temp of my apartment?  I'm just trying to think this through.

Thanks in advance!

John

should work... there are a lot of variables to figure out how much energy it would take to get your delta t though. A 48 volt element with say 3x 60 cel 300 watt panels connected in parallel would be a good start. Their peak voltage under load is about 40 volts. You would want a dc rated thermostat as wel to controll the tank temperature so you dont overheat the water... fuses to not overload the wiring...
Sounds like fun
David

Ok, thanks for the explanations.
We use Flat, unit or apartment. Flats is the main usage.

OK, basement is below ground level, we dont have them but I am familiar with them. Greta for stable temperatures.
So why is the heater set at 55, when most times the temp. is 62?
Also, would a jumper make up the difference?

Researching I found this,

oil heat and crunch the numbers on switching to cheaper, cleaner gas heating. Last winter, heating a house with oil cost an average of $1,700,
while natural gas averaged less than $900, according to the US Energy Information Administration.

I lived underground once and I used a gas hws hot water service to run a small hydronic system.
I left it running 24/7 for the length of winter.
The walls got up to temperature, they were brick and it was not expensive compared with electricity and easy to set up.
Would that work/
The HWS outside, and a small electric pump running 24/7 to the hydronic fan unit

Translation: jumper = sweater

The apartment stays at 62 even without added heat. The thermostat being set at 55, it never turns the heater on.

I think you are going to find the barrel isn't big enough and because of that your heat is going to cycle too much.   It will simply cool too much at night or on gray periods.  Or if you have enough panels to get it hot enough it will run you out on good sun days.  Guessing you will want more barrels with part insulated.  But if you plan ahead those are easily added later if you find the need.

Of course any energy you add is going to heat the apartment.  And the barrel will spread the heat over more time and also make it start later in the day so it may be heating the apartment best in late afternoon to have it ready for you to be there in the evening.  And if you have a bunch of concrete walls they are another energy storage element.  You can see how much with a simple electric heater run for a day or 2.  Most heaters are 1500 watts.  So say you were going to put in a single 250 watt panel.  Set the heater's thermostat so it runs roughly 1/6 of the time for say 6 hours a day.  Or set the timer up so it runs the 1500 watt heater 10 minutes per hour for 6 hours.  Why 6 hours.  Because in winter that is roughly the window of solid energy production from a panel.  Now if you are heating cold concrete walls you might run the experiment for a week or 2 because the heat will be eaten by the walls for a bit.  This will let you figure out how many panels you would need to accomplish your goal.

Here's a screenshot I took of David's data.  I wish it was a bit clearer, sorry!  The vertical lines represent one day and I assume it's 12am to 12am.

But from what I can tell, after about 15-20 days (I'm okay with the lag) the peak temps are at noon or shortly after and peak at about 150-160 deg F.  They seem to bottom out around 110-130 (again, after 15-20ish days) somewhere in the early hours of the morning.  

Keep in mind, David's barrel is outside.  I can only imagine getting smoother curves at higher temps when the barrel is placed in my basement.  Even at 110, it's still just sitting there radiating heat, right?

I hear you when you guys are saying one barrel may not be enough. And yes, 3 panels in parallel is my plan.  

John, I rent this flat, so I'm not switching to gas.  I'd love to know what type of electric pump you use to push the hot water around in your HWS system.  I've been thinking about something like that for a while now.

I'm not sure I'm even going to bother with a thermostat.  I would like to place a fuse inline though.  No batteries, no controllers, simple, cheap.

And I know what you all are going to say, "try it and let us know!"  haha, that's what I love about this site!

Thanks All!

I like your idea, but I would plumb in an automotive type radiator with cooling fan to help you extract that heat most efficiently when you most need it.  The fans don't have to run fast, so they wouldn't be very noisy.  Just consider that the heat extraction from the radiance of the mass of the 55 gallon barrel will be pretty slow.  But it will certainly help.