Spa Electrical Consumption

[Gomboman]

Do you know how much electricity (kWh) your spa consumes in the winter on a monthly basis? I know it depends on quite a few factors such as temperature settings, outside temperature, usage, electrical equipment, size, insulation etc.

We've had quite a few discussions about how much we pay for electricity but it's very difficult to segregate our spa usage costs unless you connect a meter to the spa. My electric company uses a sliding scale and charges penalties if you go over the alloted baseline. By the way, they only allow 187 kWh's in the winter.

I just got my last electric bill and it was $168 for 895 kWh's. If my spa only used 200 kWh's, my charges would be approximately $65 due to the penalties--calculated on the back end of the rates. That equates to over $.30 per kWh for the spa. I'm thinking 200 kWh's is probably on the low side since we use it almost every night.

Anyway, has anyone actually measured their spa electrical consumption with a meter or with some other method? I'm curious to know how many kWh's were consumed for one month. Dealers, is there an average consumption figure thrown out there for your brand? Perhaps you have data on customer spas measured in the field?

  

[Vinny]

I think the majority of us use an assumption method in calculating the amount of electricity our spas use.

I've calculated on paper what mine uses based on amperage readings.

My circ pump uses about 0.75 amps x 240 volts x 24 hours x 30 days = 118.8 KWH alone.

My 4 KW heater runs maybe 2 hours (probably 20 minutes a time, 6 times a day) total a day: 8 x 30 days = 240 KW.

I'm up to 348 KWH without using the jets yet.

I have always assumed about 500 to 600 KWH for the tub ... of course as you stated without metering it there's no way to tell.

[Bonibelle]

If Cola checks in, he can tell you in detail exactly how much electric the Epic uses.  He figured it out for me when I was having my electric crisis!

[Chad]

If I had to guess based upon my electric bills since owning my tub, I'd say no more than 200 kwhs.

[Brewman]

You are right in that KWH's used is a more meaninigful number for discussion than what your electric bill dollar total is.  
 Rates vary between regions by a significant amount.  We pay about $.08/KWH, and others I've heard pay as much as $0.20- that's over double- so throwing out just dollars is relatively meaningless.  KWH consumption is more useful.

I quit worry about that stuff a while back.  Just from experience, I know that our electric bill goes up in the winter- mainly from the spa- but also a bit for the extra time the furnace fan runs.  Bills are lower in the spring and fall, and spike back up a bit in summer when the A/C is running.  I'm to lazy to try and figure out how much the spa contributes to the bill.  

We don't have tiered rates or penalties for excessive use.  We do have a saver switch that allows the utility to cycle the A/C on and off at certain intervals when they are at a peak demand and in danger of overloading.  We get a $10 per month credit from May to September for allowing this.  Doesn't affect the spa, though- it's only hooked up to the A/C.

[thearm]

I have to agree with Vinny. By looking at past bills showing KWH used before and after the spa arrived it looks to be about a 5oo KWH difference for the same months. This is certainly nothing scientific but I have checked for several months and this is what I found. Usage on tub is at least once per day and sometimes several times. This is for the winter months here in NY.  

[Gomboman]

OK, I would like to estimate my electrical consumption for a 2005 HotSring Envoy since I don't have access to a meter. I just need some help estimating the loads for my particular equipment. Here are the items I need to calculate:

1. Circ pump = x watts
2. FWIII Ozone = x watts
3. Jet Pump 1 (Wavemaster 8000) = x watts
4. Jet Pump 2 (Wavemaster 8200) = x watts
5. Exterior light  = x watts
6. Heater wattage (No-fault 4000) = 4,000 watts
7. Typical heater cycle time for Southern California installation (102° winter) = x hours/day

If anyone can help with these figures I would appreciate it. Once I have the data I can calculate my total costs since my usage times are very consistent.

[Chas]

Circ pump - 85 watts. 75 watts for models four years or older.

Ozone - about zero in this calculation. They run 120V, 60mA - it is the wee hours of the morning and I can't do the math, but it will not be a sifnificant factor.

Jet pumps - take the HP and multiply by 745. Use actual HP, not breakdown torque or other phony numbers. The data plate on the motor will help. Amps multiplied times voltage is your wattage. Use 110 or 220 for voltage, accordingly. Some folks use 100 or 200 for ease and it's close enough.

Light in your spa is LED - insignigicant power consumption.

Heater you have. Some HS have 6000 watt heaters.

Typical heater cycle can be guestimated like this: shut off the heat - or just turn it way down - and see how much temp your spa loses overnight or for a 24 hour period. Figure that your spa heats at about 8 to 10 degrees per hour. So if your tub loses two degrees ovenight, or four in a 24 hour period, figure the heater will run less than a half hour per day. This is rough, but should get you close.

 8-)

[charstorm]

Most manufacturers post energy consumption, especially since the new rules of energy compliance CA has been implimented. A spa can cost as little as $25 a month for every day use. For instance if a spa has a circulation pump that can heat the spa 2 degrees per hour thereby eliminating the need for the heater to kick on just to maintain heat. Also some spas use 60 amps others use 30 amps thereby making one spa manufacturer 50% more efficient right out of the box. Definitely one of those items you want to inquire about before purchasing a spa.

[thearm]

Most manufacturers post energy consumption, especially since the new rules of energy compliance CA has been implimented. A spa can cost as little as $25 a month for every day use. For instance if a spa has a circulation pump that can heat the spa 2 degrees per hour thereby eliminating the need for the heater to kick on just to maintain heat. Also some spas use 60 amps others use 30 amps thereby making one spa manufacturer 50% more efficient right out of the box. Definitely one of those items you want to inquire about before purchasing a spa.

Please explain what you are talking about with the 60amp versus 30 being more efficient. I'm confused on this one. :-?

[Brewman]

Also some spas use 60 amps others use 30 amps thereby making one spa manufacturer 50% more efficient right out of the box.

Sorry, but it's not that simple.  

Electrical costs equate to power consumption-  It's a function of power consumed over a period of time.  
 A 6KW heater will draw more power than a 3KW heater, but that doesn't mean the smaller heater is more efficient.  It may have to run twice as long as the bigger heater to heat the water the same amount, and the net cost would be about the same.

 The pumps and heater are what constitute most of the power consumption on a spa.
A smaller pump may draw less power while it's running, but if it has to run twice as long as a larger pump to filter the water effectively again, there is no savings.

Design has more to do with efficiency than simply how big your circuit has to be.

[windsurfdog]

Also some spas use 60 amps others use 30 amps thereby making one spa manufacturer 50% more efficient right out of the box. Definitely one of those items you want to inquire about before purchasing a spa.

This statement is not even close to reality.  To associate energy efficiency with amperage characteristics alone is just plain uneducated.

[charstorm]

Brewman I agree with you! It's not that simple and if a smaller heater is running longer than it's not more efficient. So it goes to the design. If the spa is designed so the low amp circulation pump also heats the spa while circulating then the heater will not need to kick on except when the spa is being used, thus saving energy (based upon energy loss on a full-foam spa). And as you said this too is simplification because the efficiency of design and quality of parts greatly effect the energy consumption.

Amperage is how to measure the electricity used. If it only takes 30 amps to drive x.xxhp pumps then 60 amps to drive x.xxhp that equates to a 50% savings. ANALOGY if a car get 20 miles to the gallon it is more efficient than a car that gets 10 miles to the gallon, (regardless of the size of the gas tank and how much it costs to fill it) you will be saving money.

I find it interesting that I raised quite a few hairs but no one disputes the energy consumption guides which are B/W and a very non-opinionated way to inform consumers of an energy efficient spa with correct expectations of costs.

[Reese]

Most manufacturers post energy consumption, especially since the new rules of energy compliance CA has been implimented. A spa can cost as little as $25 a month for every day use. For instance if a spa has a circulation pump that can heat the spa 2 degrees per hour thereby eliminating the need for the heater to kick on just to maintain heat. Also some spas use 60 amps others use 30 amps thereby making one spa manufacturer 50% more efficient right out of the box. Definitely one of those items you want to inquire about before purchasing a spa.

Charstrom, you are certainly jumping into the board with some interesting perspectives. :-?  A circ pump heating two degrees an hour without the heater??  Even large jet pumps don't heat that much.  As far as the 60 amp vs 30 -- that is usually related to the number of pumps and the size of the heater -- not an indicator of efficiency, just how much the tub is trying to do.  Small, single pump spas with 1500 watt heaters have lower amp requirements, large multi-pump tubs with 5.5kW heat need more amps.  Using your MPG analogy, it is like comparing the fuel use of a MiniCooper to a BMW 7 series.  As far as the energy guides, those again are more related to size, and what they are trying to do, than efficiency.  A large freezer shows a higher energy draw than a small fridge.  The only useful comparisons that may indicate efficiency are when you are comparing similar sized/equipped appliances.

Any hairs you raised were just a reaction to these kind of IMO, inaccuracies.  One nice thing about this board is the range of perspectives, and the willingness of members to call BS when it is detected.  Welcome to the board!

[Brewman]

Amperage is how to measure the electricity used. If it only takes 30 amps to drive x.xxhp pumps then 60 amps to drive x.xxhp that equates to a 50% savings. ANALOGY if a car get 20 miles to the gallon it is more efficient than a car that gets 10 miles to the gallon, (regardless of the size of the gas tank and how much it costs to fill it) you will be saving money.

I find it interesting that I raised quite a few hairs but no one disputes the energy consumption guides which are B/W and a very non-opinionated way to inform consumers of an energy efficient spa with correct expectations of costs.

I still don't think you're aperage reasoning is all that on.  Yeh, IF spa A drew 30 amps, and spa B drew 60 AND they both ran for the same amount of time, spa A would be 50% more efficient.  But I'm not sure how to equate that to how spas work.
 Not sure your comparison is really valid.  

I didn't comment on the energy consumption part of your post because I'm not familiar with them.  

Frankly it's not a concern to me.  Annecdotal information on this board indicates to me that the quality of the insulation has way more to do with power consumption than trying to figure it out by the way you're describing it.  

A cheap crappy underinsulated spa that leaks heat out will cost more to operate than a quaility built unit that has good insulation.  
  Even if the crappy spa runs at 30 amps, it'll run more often and cost more in power.
I've seen plenty of complaint posts here over the years where some unknown brand spa that saved the owners thousands of dollars is costing that much back in electric bills.  

Efficiency goes way beyond rated power consumption.