Hi, Does anyone know if the major hot tub manufacturers make hot tubs heated with natural gas? I know you'd still need electric for filtering and pumps but I would like to heat it with gas. I've seen aftermarket heaters but why add almost $1000 to the price if you don't have too. Thanks, Jeff
If you had to shove a (low BTU) tankless WH in one I would expect at least $1K upcharge. Inline electric heaters are small and fit inside the tub shape easily, gas would be much bulkier no matter what.
If you insist, you might try plumbing a small gas tank WH in the crawlspace or nearby and rig up some sort of recirculation system with it in the loop. This would require a bit of creativity and rework. Definately not standard and causes you to put gray water through the WH tank which might have its own problems. It also adds >25Gal to the tub capacity requiring more chemicals etc.
Do you prefer gas or are you trying to avoid upgrading your breaker box from
100A to 200A? That's a better investment than a wacky hot tub IMO. Electric is more efficient than gas too, check the cost per BTU heating for gas vs electric in your area (try your utilities website)
While I would agree that an electric heater makes the best sense for an above ground fiberglass spa (ie well insulated) as opposed to a concrete in ground spa.
I must take issue with the comment that
"Electric is more efficient than gas"
In Orange County, CA here are the numbers
15 cents per kwatt-hr$1.40 per therm (100,000 btu)
3411 btu per kwatt-hrSo.......................1 therm is ~ 30 kwat-hr
equal amounts of energy (100,000 Btu).............. $1.40 for natural gas vs $4.40 for electricity
unless I made a mistake in my calcs, electricity costs about 3x more for the same amount of energy
At least in my town, electricty would have to be less than 5 cents per kwatt-hr to be equal in cost to nat gas.
cheers Bob
WHAT!!! Electricity is more "efficient" than gas - ya gotta be kidding.
Yeah, I've heard those arguements that electricity is 100% efficient at the point of use.
That arguement totally disregards the losses at the power plant, losses in the transmission lines, in the pole transformers, etc, etc.
In New England resistance electric heating is over 3 times MORE expensive than gas. In most of the US the situation is the same.
The only areas that might have cheap electric heating are those areas served by hydroelectric generating plants. That's not much of the country.
However, I agree with you about the potential difficulties of retrofitting a standard hot tub with gas heat.
Doug
For most of the US NG is still 50% cheaper than electric. Do the math with your local rates, long term for me Ng would be cheapest. I use a
450$ Bosch for all my HW and save more than 50% over an electric tank I replaced. A good electric may require a service upgrade if you are loaded on use now.
A agree. Expensive or costly is a much better way of putting it, as opposed to efficiency, which is misleading.
I'm not a hot tup owner nor have I ever been. You leave the same water in all the time, like a pool? Or, do you fill it like a tub? If you fill it, like a tub, why couldn't you just tap into a regular HW heater on an on demand heater (Even better for this application) and fill it up. Then just use the elec to maintain the temp. I suspect the cost of the water is nothing compared to the cost of keeping it hot on an ongoing basis.
hot tubs generally kewep the same water all the time... kinda gross if you ask me.
jacuzzi bathtubs get filled and emptied after use a much better arrangement
Thats kind of what I thought - Why not use it like you would a jacuzzi? Fill it every time? I would assume it has a gravity drain. That coupled with your favorite NG demand (Tankless) water heater and then you only need 'lectric to maintain the heat while you are using it. Why am I even commenting I know sh** about hot tubs.
=================== Why all the fussw..Most Hot Tubs come with an electric heater... My hot tub is kept at 102 degrees, 24/7 x 12.... location is in Western Maryland.( 20 minutes to Pa, 15 to either WV or Va.. 60 miles from DC...
Cost averages out to about 20 bucks a month ..for that kind of money having the tub ready to use at any time is, at least in my opinion, cheap...
It could be made slightly cheaper by installing more then standard insulation inside the enclosure... plus if you want to wait to use it later inthe day...just keep it cooler... tuen it up a few hours before use and save a buck ...
Just my opinion... Electrifc rates here are about 7 cents a KWH after they add tax, fees, (and distrubution ..delivery... charges (???) etc...
Bob G.
Because they can take 250 gallons of water and it will take quite awhile to fill it each time it's used for one. Then there is the issue of having the correct water chemistry, unless you want to get in a tub with multiple people and no bromine disinfectant. At least with the chemicals I use it takes hours to establish the correct level. They are insulated, so unless it's a long time between uses, it's going to take more energy to warm up 50 degree water every time you use it, plus if you use it 4 times a week, that's 48000 gallons of water a year compared to maybe 1500 gallons. And then there is the problem of what to do with it in parts of the country that get below freezing in the winter. Full and with heater maintaining even a lower temp, it won't freeze. But if you drain it, now you have to fully winterize it, which means getting all the water completely out, which isn't that easy on some units.
Even a relatively small hot tub holds about 250 gallons. Draining it is not at all like draining a bathtub, either. It's not hooked up to the house plumbing, so you need a place for all that water to go. There will always be a gallon or two of water that must be bailed and sponged out of the very bottom. It also means taking off an access cover to drain it, and blowing compressed air through all of the pipes to clear them so nothing grows in them while dormant. When you refill the tub, you would also have to bleed the plumbing. It's not that hard to do a few times a year during normal water changes, but draining and filling a hot tub between each use would be moronic.
It's not a problem to keep it sanitary, and it's not expensive to keep it heated.
You change the water about 4 times a year depending on usage and other factors.
Finally, having used both a jacuzzi and a hottub, I can tell you that a jacuzzi does not give anywhere near the same experience. It's a pretty poor second place at best.
I did mean efficiency!
You've mistaken efficiency for cost of ownership. (though I did leave room for y'all to fill in what you wanted, I'm not suprised by the confusion)
I should have gone on further to say: "Electric is more efficient than gas too, check the cost per BTU heating for gas vs. electric in your area (try your utilities website) [To see which ends up costing less]. (With current trends, it may only be a few more years before Electric is cheaper)
I was referring to the fact that 100% of the electric energy is converted to heat while a gas system has to vent at least some heat out the flue with the combustion gasses.
Efficiency is the ratio of energy spent to that used to do useful work (in this context). And that's the way I used it. I would have used the word value or cost if I meant that.
Why would anyone care which is more efficient? The real issue is which is going to cost more for fuel to get the same amount of heat and the above statement you posted makes the claim that electric is cheaper than gas. I don't anywhere that you can heat anything with electric for less than natural gas. There probably is some screwy place where that exists, but by and far, electric resistance heating is the highest cost way of heating anything, which is why it's used as a last resort.
The efficiency issue is a red herring because while gas may be 80-95% efficient, vs electric at 99.9% at the point of use, that still doesn;'t make it anywhere near as cost effective as gas. And then if you want to take some environmental view and look at the big picture, electric becomes way less efficient because the prime mover used to create it isn't 100% efficient and there are significant losses in distribution. In fact, some electric is even produced from natural gas to begin with. You still think it's more efficient burning gas 500 miles away, converting it to electric, sending it down a line and then running it through a resistor, as opposed to just burning it there?
Now your just turning this into a physics NG, I was just clarifying an incomplete sentence.
Electric is more efficient at the point of use than gas (although more expensive), but it certainly isn't more efficient overall. Most of that electricity will come from burning a fossil fuel, and it is more efficient to burn it directly at the point of use.
Cheers, Wayne
Make sure you understand this correctly...
In many applications, at the point of delivery electricity is 100% efficient, something a gas combustion burner will never approach. An electric hot water heater may be said to be 100% efficient minus whatever heat leaks out through the casing and the attached pipes.
However, even with the inefficiency of gas, this ignores the economics that give gas a much higher heat content, so that even a gas hot water heater that is only 65% efficient is still cheaper to run than an electric, even though about 35% of the heat goes up the flue.
Beachcomber
The chemicals used in a hot tub, chlorine, bromine, ozone, etc. are used to kill that bacteria that might otherwise form from keeping a standing body of warm water for an extended period of time. The human body sheds a layer of skin while bathing and filtration is necessary to collect this and the other organic solids that will otherwise collect in the water.
If you pay for city metered water, the expense of filling up a 250 gallon hot tub every other day would quickly add up. Also to bring that much water to an operating temperature of 101 F would be high compared keeping the tub at some standby intermediate temperature and just applying heat to make up for the losses.
Beachcomber
It's not unusual for an in ground spa to have gas heated water. It's unusual for this heat in a hot tub, however. Gas heaters are fairly expensive, require piping for the gas and are large enough that they don't fit inside a hot tub enclosure. A small gas pool/spa heater is probably around $1200, where an electric immersion heater is around $200.
That said, because the electric heater is nowhere as powerful as even a small gas one, it is customary to keep hot tubs heated 24/7. Otherwise, it'd take a day or so to reach temperature. With an external gas heater, you could fire it up a half hour or less before getting in and have great hot water. That sways things in favor of a gas heater, if you want to save on operating costs.
At a mountain cabin we owned, I had a hot tub with an electric heater. Since LP was nearby for our furnace, I considered getting one of the smallest LP- fired gas heaters and using it as the primary heat source, with the electric heater merely being used to keep the water at 40f to prevent freezing.
Frankly, in my younger days, I'd have considered buying a domestic gas-fired water heater in the 30-gallon range and hooking it to the the hot tub, using a circulating pump. I'd have built a little enclosure for the water heater to protect it from snow and rain. I'd have kept the electric heater for backup or for when I would have shut the gas system down to prevent freezing when we'd be away for several weeks.
Pardon me. It's happy Hour here, and I have a 100f in ground spa awaiting me and my martini.
Mark
Beachcomber wrote:
???
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.