Considering a drip BBQ or pool heater

[cgoodwin]

I have been thinking about a VO drip BBQ but wonder if the food would taste like VO?

On the same note I recently found a brand new 15' across above ground pool for $200 on CL. I am considering putting it in the backyard for the little girl and heating it with a VO Drip heater..

Maybe even a lightly modified gas water heater. Remove the gas burner and put in a drip pan with a fuel line running down the flue, needle valve adjustment, exterior tank. That and a simple pump, maybe even solar, and I bet I could keep it warm in the cold seattle summer...

[HarryN]

While I am a big fan of using WVO for fuel, I am not so sure about using it for food cooking without some real thought on the approach.

I use an LP gas grill a lot, and of course most of the flavor comes from the smoke from the food's natural drippings smoking up. It would be really annoying to have my personally seasoned chicken or steak taste like whatever was in the fryer oil. Even with a LOT of grilling, we really don't use that much LP, certainly less than 30 gallons / year and more likely 1/2 of that.

On the point about a pool or hot tub, now those are serious energy users, making them a natural user of WVO. Adding together the heating use and running filtration pumps, it might be worth even considering to run a small diesel generator and heating with the waste engine heat. Of course, electricity prices are considerably lower in WA than CA, so that is a big factor. At a tier price of nearly $ 0.40 / kwh, it is approaching robbery and certainly doesn't do anything to promote electric car concepts if you are into that sort of thing.

I suppose that an inventive guy could even find a way to just run his WVO powered truck an hour or so and heat up the pool from the waste heat, but I guess idling isn't really ideal.

If you can swing it, consider to use ozone as the primary disinfectant for the pool, with just modest use of chlorine. The chlorine tablets and liquid byproducts build up in the water, while the ozone just burns it off and goes away. Cl2 gas also works, but this approach is not really for an area with children.

Solar thermal heating is pretty straightforward esp. if you are not super picky about water temperature control. A long spiral of black pvc tube on a roof along with a low flow rate pump is all you need. A 1/10th hp pump is usually enough for slow water circulation like this.

[HarryN]

I went back and ran some quick back of the envelope calcs for how much heat is needed to warm the pool a bit.

Here are my very quick estimates:
- 6,000 gallons or 24,000 liters or 24,000 Kgrams
- water entering pool at 10 C heating it up to 20 C in one week
- I didn't include any heat losses yet for this rough calculation
- 4 J / g-K heat capacity of water
- One week to warm up, approx 605 x 10 >3 seconds
- est 1 x 10 >5th KJ required to heat the pool per degree K (or C)
- Est at least 1 KW of power, 24 hours / day to keep the pool warm, possibly as much as 5 KW

Solar radiance on a roof in Seatle, nominal 500 watts / sq meter during daylight hours (perhaps 10 hrs max)

Absolute minimum solar thermal heating needed (if my numbers are close) is 5 square meters, and might be as much as 25 square meters.

I didn't double check these numbers, so anyone feel free to run a double check and point out my errors.

From a generator perspective, this is getting close to the practical recoverable heat from a 10 hp generator. (Assumed 10 HP generator is nominal 5 KW, creates about 20 KW of heat, and 20% is recoverable for the pool heating)
-

[Brendan C]

Originally Posted by HarryN

If you can swing it, consider to use ozone as the primary disinfectant for the pool, with just modest use of chlorine. The chlorine tablets and liquid byproducts build up in the water, while the ozone just burns it off and goes away. Cl2 gas also works, but this approach is not really for an area with children.

We converted our pool to salt water. Pretty neat setup. Electrolysis splits the NaCl as it passes through a module installed just after the sand filter container. This creates Cl gas in the water effectively killing anything in the water. Before the water is a few feet past the module, the Cl recombines with the Na. Bingo, salt water again.

Originally Posted by HarryN

Solar thermal heating is pretty straightforward esp. if you are not super picky about water temperature control. A long spiral of black pvc tube on a roof along with a low flow rate pump is all you need. A 1/10th hp pump is usually enough for slow water circulation like this.

I snake a black hose across the driveway to and from the pool pump to absorb the solar radiation. Cheap and it works well.

[HarryN]

Originally Posted by Brendan C

We converted our pool to salt water. Pretty neat setup. Electrolysis splits the NaCl as it passes through a module installed just after the sand filter container. This creates Cl gas in the water effectively killing anything in the water. Before the water is a few feet past the module, the Cl recombines with the Na. Bingo, salt water again.

I snake a black hose across the driveway to and from the pool pump to absorb the solar radiation. Cheap and it works well.

Hi Brendan, any idea how much salt is in the water, I don't have a good feel for this, so I guess compared to the ocean or something?

[Brendan C]

Hey Harry,
It's not nearly as salty as the sea. As far as exact salt concentration, I'm not sure off hand. I can take a sample to get tested and get an answer for you if you'd like. Overall, it is much more refreshing than a traditionally chlorinated pool. Easier on the skin and suits and very hands off.

[HarryN]

Originally Posted by Brendan C

Hey Harry,
It's not nearly as salty as the sea. As far as exact salt concentration, I'm not sure off hand. I can take a sample to get tested and get an answer for you if you'd like. Overall, it is much more refreshing than a traditionally chlorinated pool. Easier on the skin and suits and very hands off.

Hi Brendan, it is more just curiousty than anything else. We belong to a community pool that switched from Cl2 gas to liquid + solid chlorine sources a few years ago, and the pool water is much harsher on the skin now.

I was not aware of the salt water approach and just wondered how it was, as my wife cannot open her eyes in sea water. I will look around on the internet for some more info.

Since you are using a very simple hose heating method for warming your pool, do you think my calculations are way off?

[DieselBurps]

Originally Posted by HarryN

Hi Brendan, it is more just curiousty than anything else. We belong to a community pool that switched from Cl2 gas to liquid + solid chlorine sources a few years ago, and the pool water is much harsher on the skin now.

I was not aware of the salt water approach and just wondered how it was, as my wife cannot open her eyes in sea water. I will look around on the internet for some more info.

Since you are using a very simple hose heating method for warming your pool, do you think my calculations are way off?

That's not a fair comparison as a community pool most likely has a much higher concentration of chlorine to it to compensate for all of the people peeing in the pool as well as the diaperless babies...!

The salt water in the pool is substantially less "salty" than the ocean - but it still leaves a layer of salt on the skin and the definite feeling that you need a shower after being in the pool. Your eyes should NOT be affected by the level of salinity in the pool.

A chlorinated pool needs to be watched fairly closely - if you have a lot of pool activity and the resulting contamination that occurs with people going in and out of the pool (preferably NOT peeing, just tracking dirt in) - you'll have to up the chlorine level a bit to compensate. If you don't track the chlorine level to the usage, you'll either end up with too little chlorine and the resulting algae - or too much and the burning skin sensation. Heating the pool will cause more chlorine to burn off - so if you get the pool nice and warm, you'll want to take a few minutes several times a week to keep tabs on the chlorine & pH levels.

A private, well maintained chlorinated pool should never burn the eyes or skin. A public pool is more like a septic tank.

[cgoodwin]

Personally I hate chlorine, it is bad for you, absorbs through the skin, has to be checked and added all the time, salt pools still need to be checked some times but you don't have to add the NaCl, mix it in and wiat while your eyes and nose a re burnign before dropping your kid in again.

Either way you can just not add any NaCl for a few days or leave the NaCa system off and leave it exposed to sunlight and the Ph will normalize, then the water can be used on your yard without killing everything and the pool drained. I am not sure if this is as simple with a Ca pool as it is with a Ca pool.

Tried a solar heater a few years ago, I would need to cover the whole neighborhood to get any results here.

[DieselBurps]

Originally Posted by cgoodwin

Personally I hate chlorine, it is bad for you, absorbs through the skin, has to be checked and added all the time, salt pools still need to be checked some times but you don't have to add the NaCl, mix it in and wiat while your eyes and nose a re burnign before dropping your kid in again.

I concur, but when you own the pool and can control the volume of traffic it sees, it's pretty easy to keep the chlorine levels down around the 3 ppm level and you really don't notice it much at all. The electrolysis/salt setup needs to keep the level there too - so there isn't much difference. FWIW - I've only maintained my own chlorine pools and assisted with a salt water pool. The salt water setup is good if you are absent for extended periods - it's a more automated system. It still needs to be checked as if there is a failure, the pool will turn green pretty quickly.

Originally Posted by J_Galt

Either way you can just not add any NaCl for a few days or leave the NaCa system off and leave it exposed to sunlight and the Ph will normalize, then the water can be used on your yard without killing everything and the pool drained. I am not sure if this is as simple with a Ca pool as it is with a Ca pool.

You'll want to be careful draining a salt water pool - the saline level isn't as high as the ocean, but it can still kill some plants. A chlorinated pool loses chlorine pretty rapidly if it is heated - or if large volumes of rain fall - something that will help up there.

Originally Posted by J_Galt

Tried a solar heater a few years ago, I would need to cover the whole neighborhood to get any results here.

When solar power was being discussed back in the '70s, I wondered what the point was. Living east of Seattle - we rarely saw the sun and the energy absorbed wasn't anything like the magazine articles described.