As stated, the main panel uses a 100-amp dual pole breaker for the line to the sub. I have not verified the actual wire itself and am not certain how I would go about doing that. The sub currently only powers our 1 hp pump on a 20 amp dual pole and the pool light on a 15 amp single pole. I'd have to figure out the load for the main breaker but my current assumption (yes we all know about assumptions) is that it can handle whatever the sub panel can. It appears to be designed with heavy use in mind due to the 100 amp dual pole breaker, and our main panel currently has several breakers that aren't even being used including one for a water softener and one for a garbage disposal so it's not using everything it was installed / designed for.
Electric Spa Heater for Spillover Spa?
- Thread starter wsamon
- Start date
As stated, the main panel uses a 100-amp dual pole breaker for the line to the sub. I have not verified the actual wire itself and am not certain how I would go about doing that. The sub currently only powers our 1 hp pump on a 20 amp dual pole and the pool light on a 15 amp single pole. I'd have to figure out the load for the main breaker but my current assumption (yes we all know about assumptions) is that it can handle whatever the sub panel can. It appears to be designed with heavy use in mind due to the 100 amp dual pole breaker, and our main panel currently has several breakers that aren't even being used including one for a water softener and one for a garbage disposal so it's not using everything it was installed / designed for.
What the panels have in them for breakers is not the issue. The issue is what size wire supplies electric from the meter base to the first panel. How much load is on that wire. Then what size wire is from the main to the sub-panel. If those wires are not large enough to pull the load you are going to be really upset. There is a time to call in an electrician and this is the time to verify what you are working with and what you are planning. IMHO what you are planning on doing is not going to work the best. I have a stand alone tub that is insulated and it takes it up to 12 hours to heat from 86 degrees to 104. Also as a side note you are going to have to have a temperature control on the heater to restrict the element to keep it from over heating the water.
The 11,000 watt heater will draw 46 amps and need a 60 amp breaker. So, your light probably draws 5 amps and the pump 7 or 8 amps.
So in theory I should have plenty of juice at the sub panel (46 + 5 + 8 = 59 on a 100 amp breaker) but everything needs to be verified by having an electrician look at the actual wiring including the power company's one coming into the main panel in the garage.
This is contrary to most things that I have heard on this thread and elsewhere, including calculators. When most claim it should take under an hour for an 11 kw heater to heat 200 gallons 20 degrees (see below), yours takes 12 times that to go up 18? That difference seems substantially more than the "theoretical vs reality" gap. Are the calculators really that far off or is there something else here?
http://www.ecosmartus.com/Assets/ecosmart/file/Spec%20Flyers/Pool%20and%20Spa%20Sizing%20charts%20pdf%20for%20web.pdf
I already did the math on 5500 watts so it is easy to just double it. 
I like easy!
So, on 250 gallons doubling the watts should yield 14 degrees per hour.
200 is
200 x 8.34lbs = 1668 lbs
1668 lbs ÷ 14,960 (18,700 x 80% efficiency) btu = 0.11 hours to heat 1 degree
0.11 hours per degree equals 6.6 minutes or a little over 9 degrees per hour
Or 18 degrees per hour for 11,000 watts
I would expect that heater has a thermostat to set the heat point and that it is capable of maintaining a certain temp in the tub. It is a good idea to make sure that it can and will to avoid surprises.
I like easy! So, on 250 gallons doubling the watts should yield 14 degrees per hour.
200 is
200 x 8.34lbs = 1668 lbs
1668 lbs ÷ 14,960 (18,700 x 80% efficiency) btu = 0.11 hours to heat 1 degree
0.11 hours per degree equals 6.6 minutes or a little over 9 degrees per hour
Or 18 degrees per hour for 11,000 watts
I would expect that heater has a thermostat to set the heat point and that it is capable of maintaining a certain temp in the tub. It is a good idea to make sure that it can and will to avoid surprises.
I already did the math on 5500 watts so it is easy to just double it.
So, on 250 gallons doubling the watts should yield 14 degrees per hour.
200 is
200 x 8.34lbs = 1668 lbs
1668 lbs ÷ 14,960 (18,700 x 80% efficiency) btu = 0.11 hours to heat 1 degree
0.11 hours per degree equals 6.6 minutes or a little over 9 degrees per hour
Or 18 degrees per hour for 11,000 watts
I would expect that heater has a thermostat to set the heat point and that it is capable of maintaining a certain temp in the tub. It is a good idea to make sure that it can and will to avoid surprises.
Honestly, I forgot that your post had some efficiency built in and could be used for more realistic calculations than the best case scenarios mentioned on the sites. Still, it goes back to my point. Your math says 18 degrees in 1 hour. The other poster said 18 degrees in 12 hours for his spa. Something's not right somewhere.
The problem with the 18 degrees in 12 hours statement is that it just stands by itself. We don't know what the inputs are (Btus) or the amount of water being heated. Older tubs (even if insulated) are significantly less insulated than newer tubs. So while the statement may be true its difficult to directly compare. I too am a bit skeptical but frankly this seems doable. I'm most concerned about how much heat the ground will suck out of the water. Generally the ground is a good insulator. So I want to know how this works.
Here is the manual for the heater: http://images.inyopools.com/cloud/documents/cz-11-instruction-sheet.pdf
It answers many of the questions raised above.
Here is the manual for the heater: http://images.inyopools.com/cloud/documents/cz-11-instruction-sheet.pdf
It answers many of the questions raised above.
CJadamec
TFP Expert
The calculations don't take into account the thermal mass of the concrete in the spa. You arent just heating the water you are heating everything it touches. If you read the brochure from Hayward about the heater the published numbers for heat rise are for an insulated and covered spa. You will have a cover on your spa which will help not having insulated sides will slow things down a bit I can't say how much though.
Exactly correct you have a spa that is concrete. It is going to be harder to heat that than a fiberglass shell that has 4" of foam insulation over 100% of the exposed shell underneath. How much of your shell is above grade? How sure is your 200 gallon estimate? I forgot to take into account my spa is 375 gallons. I still don't see an electric heater doing a 15-20 degree rise in an hour. I am skeptical because I know from my own experience I don't get that much rise from a two speed pump circulating on low speed when it calls for heat.
FWIW, I heard back from the people that did the resurfacing and modifications to my pool a couple years ago. They said "The 11KW heater is likely not sufficient enough to operate your inground hot tub. They are designed for above ground units." and that "The 11KW coil based heater requires a 60a dedicated fused line" so I couldn't connect it to the sub-panel. A heat pump would also require a dedicated line separate from the sub-panel. I'll ask a couple more places, but it looks like I'm down to trying to get lucky on Craigslist, waiting a couple years, or just tacking it on to the CC debt we're trying to pay off...
On CL so far I've found
Pentair Mastertemp 300k BTU propane for $700
Hayward H200 200k BTU propane for $500
Jandy Lite 2 400k BTU propane (model LJ400P, 2006 model) that looks a little rougher cosmetically but supposedly functions fine for $450
Aquapro 1300 that appears to be a 125000 BTU heat pump that supposedly was "only used 6 times" but "needs a small new tube because it leaks a bit" for $150
Does anyone have any comments on the viability, quality, etc. of these? Initially I'm inclined to ignore the Aquapro because needing a new part after only 6 uses sounds fishy to me and I've seen some low ratings for them online. Not to mention it will require the electrical work for the install and only provides 125k BTUs
I like the 400k BTUs of the Jandy, but it's already 11 years old and looks good. Paint would probably go a long way with that, but what's the shelf life of these things? Could I expect to get even 3 or 4 years out of it? How is Jandy in general for heaters?
Other than the BTUs is there any appreciable different between the Pentair Mastertemp and Hayward H200?
On CL so far I've found
Pentair Mastertemp 300k BTU propane for $700
Hayward H200 200k BTU propane for $500
Jandy Lite 2 400k BTU propane (model LJ400P, 2006 model) that looks a little rougher cosmetically but supposedly functions fine for $450
Aquapro 1300 that appears to be a 125000 BTU heat pump that supposedly was "only used 6 times" but "needs a small new tube because it leaks a bit" for $150
Does anyone have any comments on the viability, quality, etc. of these? Initially I'm inclined to ignore the Aquapro because needing a new part after only 6 uses sounds fishy to me and I've seen some low ratings for them online. Not to mention it will require the electrical work for the install and only provides 125k BTUs
I like the 400k BTUs of the Jandy, but it's already 11 years old and looks good. Paint would probably go a long way with that, but what's the shelf life of these things? Could I expect to get even 3 or 4 years out of it? How is Jandy in general for heaters?
Other than the BTUs is there any appreciable different between the Pentair Mastertemp and Hayward H200?
CJadamec
TFP Expert
If you have a 100amp run to your sub panel then you don't need a new power supply. But that's why we said you needed to have that verified. The builder you talked to most likely assumed you had a smaller electrical supply to your pool panel. A 100amp panel is not a common thing.
That aside I wouldn't buy a heat pump known to be broken. Getting them repaired is not always an easy task.
That aside I wouldn't buy a heat pump known to be broken. Getting them repaired is not always an easy task.
Agree, if you have 100amp service at your sub-panel then adding a 60a breaker is fine.
Also agree that a broken heat pump can cost a lot to repair. Could be a compressor or thermal expansion unit or reversing valve, all can push 1000 bucks to replace.
The gunite and ground around it will work against you for a while but once warmed up they will also work in your favor. When I am heating up my pool in the spring with my solar panels it takes a while to get it all warmed up. But once it is it holds temp great. I wouldn't give up on the 11k heater. You may decide to run periodically and keep it at 80, 85 or even 90 for quicker heat up.
A heat pump will work fine also. Same idea, keep the water somewhat warm and then heat up as needed.
Also agree that a broken heat pump can cost a lot to repair. Could be a compressor or thermal expansion unit or reversing valve, all can push 1000 bucks to replace.
The gunite and ground around it will work against you for a while but once warmed up they will also work in your favor. When I am heating up my pool in the spring with my solar panels it takes a while to get it all warmed up. But once it is it holds temp great. I wouldn't give up on the 11k heater. You may decide to run periodically and keep it at 80, 85 or even 90 for quicker heat up.
A heat pump will work fine also. Same idea, keep the water somewhat warm and then heat up as needed.
If you buy from CL you understand you can get something that works a few hours, week, or maybe longer. No one should ever consider an 11 year old unit. I just pulled a 11 year old Jandy out because it was rusted out on the bottom and the header was rusting inside putting rust into the water. I also have two old Sta Rites in the garage that have leaks in the heat exchanger but unless you hook it up you would never know. In fact I bet it will work for close to one week and then you'll be calling me. My point is, you take a $400 or so risk buying off of CL.
I would save your cash or invest your income tax refund to buy a new gas heater. You can get by nicely with a 250K or in the case of Raypak, a 266K BTU unit.
I would save your cash or invest your income tax refund to buy a new gas heater. You can get by nicely with a 250K or in the case of Raypak, a 266K BTU unit.
I did mention that it was fed by a dual-pole 100 amp breaker. They didn't seem to care either way. I'm going to get some second opinions and see what other installers think. In my perusal of CL I found someone selling an 11kw heater because they were replacing it with a whole pool heater. I messaged them and found out they used it in the same situation and claimed it worked well and "heats quickly" but depends on the temperature you need. Of course they also have incentive to say that it works well...
We can keep the water at 80 for about 5 months (?) using just the solar cover, so that's not much of an issue. If we wanted it starting at 85 - 90 then we'd need to run the heater periodically. I wonder how often that would be, and the cost it would generate. Money is a big concern right now so we're trying to keep our bill increase minimal.
Supposedly the heat pump only needs a tube that "is cheap", but I'm pretty sure I'll avoid it. It just isn't worth the risk, especially when factoring in the higher cost of the install.
I'm well aware of the risks of buying on CL. The person could be outright lying to you and sell a completely faulty unit and you effectively have no recourse. I also got mildly hosed in the past buying power tools where the tools worked well enough but the batteries lost their power after 5 minutes. Of course they lasted long enough for a brief demo before I completed the transaction... I'm really hesitant about going this route, but we just don't have many options that work with our minimal budget.
Our income tax refund is going toward paying off credit cards that will be losing their 0% rate at the end of summer. We've had a lot of one-time expenses in the last 2.5 years and only had/have my one income for another year, so our debts are much higher than we'd like. In the same vein, it's going to take at least a year, if not more, to save up enough money to buy a $2000 heater due to continuing to pay off the debt.
My wife is getting increasingly frustrated about her lack of being able to use the pool and especially spa due to water temps (she's from the Dominican Republic and is used to bathtub temp waters year round) and desperately wants a heater for the spa at least. I'm trying to do this for an anniversary present in a month. It doesn't necessarily have to be a permanent solution. If I can keep the expenses to the neighborhood of $1000 up front and < $100 / month and get maybe 18-24 months out of it we could look at replacing/upgrading then.
The Mastertemp and H200 seem to be newer models in decent shape but I just don't know about buying these things on CL.... I feel like there's too many things that could be wrong and I just wouldn't know until after the transaction...
CJadamec
TFP Expert
Not for nothing, and I'm definitely not suggesting you buy the broken one, but I think based on what you are looking for a heat pump will make you and your wife the happiest. It sounds to me the way you describe her words is that she wants the pool maintained up to temp all the time. The heat pump will by far have a lower utility cost, when compared to propane, month to month.
I've seen people on here time to time find used ones on CL in FL. As you are aware of the risks buying things on CL try to do as much homework as possible. By the time you buy a used gas heater and have the tanks installed you are spending the kind of money to probably get a decent used heat pump. I would definitely seek the opinion of another pool builder in your area about what you are looking for. You might even find one with used equipment to sell you.
I've seen people on here time to time find used ones on CL in FL. As you are aware of the risks buying things on CL try to do as much homework as possible. By the time you buy a used gas heater and have the tanks installed you are spending the kind of money to probably get a decent used heat pump. I would definitely seek the opinion of another pool builder in your area about what you are looking for. You might even find one with used equipment to sell you.
I agree that a heat pump would be a good option to heat your spa and your pool. But, I wouldn't buy a used one unless it can be powered up and tested by an HVAC pro before you buy it. They can tell a lot in a few minutes of running it.
Thanks for the info. Just to be reasonably clear on the priorities (and yes, this is from both of us
):1a Cost (equipment + installation + usage)
1b Heat 200 gallon spa to 100+ degrees in reasonable time (~ 1 hour or less)
2 Movie screen visible from hot tub
3 New tile/paver deck
4 Heat pool
Heating the whole pool would be nice, but we both realize this is probably unrealistic. While cheapest to operate, even a heat pump is probably more expense than we want to take on to keep the pool warm all the time, and the times that we know 2 days in advance of when we want to use the pool are pretty rare. As long as she can use the hot tub to relax and ease muscles she'll be happy. Especially if she can use it while watching a movie and drinking a cider.
My initial thought for heating the whole pool is to get a solar system. The reason I'm considering propane for the spa is because we already have a propane heater installed. It's just dead. The electric is run, the plumbing is in place, and the gas line is already run. So it should be the simplest install. All we need is the heater itself and the tank, which I've heard you can lease from the propane companies if you agree to purchase a certain amount per year. I'm in the process of determining how much that will cost. On a related note, does anyone have any real world examples of how much propane they use in a year heating a similarly sized spa? (I know there's a ton of variables)
CJadamec
TFP Expert
For heating a spa no, but I burn around 1000 gallons a year to heat my house, cook, make hot water, and dry my clothes. So you will burn less than that. That's for a family of 5 in a 2000 sqft house.
But.... for a guideline to your answer. Propane contains about 91,000 BTU's per gallon. Lets say you have a 220 kBTU heater. If that heater were to run full flame for an hour it will consume about 2.4 gallons of propane. Lets say you turn on the spa 3 days a week and it takes 30 min to heat up and maybe another 10 min heater run time while you are using it. That works out to about 1.4 gallons per spa day and about 4.2 gallons a week. Almost 17 gallons a month and so on down the road. Obviously your particular installation and usage will need to be considered when you end up on the equipment.
You will then need to know how much per gallon that propane is going to cost. Last time I bought propane I paid about 1.60 a gallon, however I own my tank and consume 1000 gallons a year and by from the same company. If you lease a tank you will pay fees every time you get gas, you will pay a penalty if you don't burn enough gas, and you will pay a higher per gallon price because you don't use that much gas. I know people in my area who have leased tanks and are using the same amount of gas as me and paying about a dollar per gallon more than I pay because I own the tank. A leased tank is probably a great option for you and probably what the previous owner had which is why the tank is gone. Shop as many propane companies as you can to try and get the best lease terms because once you lease a tank the only person who can fill it is the person you are leasing from. In other words propane pricing is really really screwy.
But.... for a guideline to your answer. Propane contains about 91,000 BTU's per gallon. Lets say you have a 220 kBTU heater. If that heater were to run full flame for an hour it will consume about 2.4 gallons of propane. Lets say you turn on the spa 3 days a week and it takes 30 min to heat up and maybe another 10 min heater run time while you are using it. That works out to about 1.4 gallons per spa day and about 4.2 gallons a week. Almost 17 gallons a month and so on down the road. Obviously your particular installation and usage will need to be considered when you end up on the equipment.
You will then need to know how much per gallon that propane is going to cost. Last time I bought propane I paid about 1.60 a gallon, however I own my tank and consume 1000 gallons a year and by from the same company. If you lease a tank you will pay fees every time you get gas, you will pay a penalty if you don't burn enough gas, and you will pay a higher per gallon price because you don't use that much gas. I know people in my area who have leased tanks and are using the same amount of gas as me and paying about a dollar per gallon more than I pay because I own the tank. A leased tank is probably a great option for you and probably what the previous owner had which is why the tank is gone. Shop as many propane companies as you can to try and get the best lease terms because once you lease a tank the only person who can fill it is the person you are leasing from. In other words propane pricing is really really screwy.
This is what I'm trying to figure out. I can use the various calculators and throw in some inefficiency fudge factor for figuring out how much will burn to get from temp x to temp y, but what about keeping it at temp y for an hour? That's the part I'm really unsure about and it plays a big role in how much propane is used.
I've been trying to do this recently but have only found 2 propane companies that service my area so far: Amerigas and Ferrell gas. Amerigas wouldn't give me a lick of information without an onsite appointment, which of course they can't attend until the middle of April. Ferrell was extremely helpful and gave me the following info:
Installation of a leased 100 gallon above ground tank, including an initial fillup, should run me about $500.
The tank lease is $96 / year
Fill up is anywhere from ~$2 to $5 / gallon depending on the time of year and commodity prices + a $20 delivery charge. Currently, it's $4.60 / gallon, which she claims is one of the more expensive times of the year.
There is no penalty for not using enough gas, and no "fillup agreement." They fill on-demand, whenever I call with a few days notice.
They won't lease an underground tank, but gave a rough estimate of $2000 to buy one, have it installed, and pay for permitting.
They will fill resident-owned tanks and I think it's $1 / gallon less, just like your friends
I totally missed when you posted this. I'm not sure what you're asking with how much of my shell is above grade. If you mean above ground, none of it is. I didn't exactly drain the water out of the spa into measuring buckets or anything but I took dimensional measurements using a tape measure. It's round, 5'10" in diameter, 2.5' deep in the middle and 1' deep at the sitting ledge which is 1.5' wide IIRC (having trouble finding the paper). I didn't bother to measure the entry step which would take away a few more gallons as well.