With electric rates near 12c/kwh(peco philly), My question is how much it costs to heat up the spa from 70 degrees F to 95' 500 gals
Part 2 would be what does it cost to run the circulating pump system. It usually gets run 1 hour and it totals 11.5 hp. I've been thinking about this for a while. Thanks M
Spas can be set to all sorts of settings. They can be set to filter for different amounts of time. They can be set to economy or standard, meaning that during economy, the heater only comes on during filter cycles. In standard mode, it comes on whenever the temp goes under the preset.
There is much argument/debate/discussion/hysteria over the advantages/disadvantages of leaving it on all the time, or leaving it where it will maintain a constant temperature. That, of course, depends on the ambient temperature, since a spa inside a house in a "spa" room would not cool down as quickly or as much as one outside. And then, there's the balance argument of: which costs more ....... to keep a spa hot, or bring up the temperature 20 degrees every time I want to use it?
My Catalinas heat up at the rate of five degrees an hour. When I change the water, I use pool water, as it is generally warmer than tap water, and when the solar is going on the pool, it is a lot warmer than tap water.
It is impossible to estimate the answer to your question. It is all intellectual mathematical masturbation.
It is what it is. If you want a spa, you will deal with it.
I love my spas, and spend more time in them than in the pool on a whole year basis.
A better quality spa will cost less than an El Cheapo from Homer's. They have better heaters, motors, and piping, which circulates the water better.
If you want one, get one, and fergeddabout the cost. If it makes your electric bill jump too much, adjust, and then if it is still too much, get a better job or do other things to increase your income.
If the pump is totaling 11.5 hp, that is over 36 amps of power at 240 volts. About 8600 watts at .12 per kW it will cost over a buck an hour to run.
A Btu is the energy that it takes to raise the temperature of 1 pound of water 1 degree. You need to know the correct weight of the water (have you found that out yet? it was wrong yesterday) and the number of watts of energy that is equal to. All this information is easily found. If you have a program like Convert it is much easier to work with.
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Other factors to consider. Where is the heat loss from the spa going? If it is in the heated house, it is not lost, just distributed to ease the load of the home heater. Are you maintaining the temperature for a length of time? Where is the 70 degree water coming from? This time of year incoming water is much colder.
You are talking about ~ 100,000 BTUs at 3400 BTU per KWH is 29.4KWH times 12 cents is $3.52. That assumes no loss to the air. If you have a well insulated, covered spa that is noit a huge number but it is a number. I have a similar spa and I usually just assume $4 when I heat it up.
It's not that expensive to run a spa. What you fail to realize is that there is very little heat loss on spas. I work at a retail spa outlet and it costs about $1/day to run a hot tub (not including chemicals) and depending on the insulation. Ours are insulated around the cabnetry which offers better heat retention than the foam on the bottom of the tub.
snipped-for-privacy@ece.villanova.edu This debate would be among people who know nothing of 300-year-old physics? :-)
Yes, I have to agree with that one. There is absolutely no question that lowering the temp on a spa, for any period, then raising it back up for use, saves energy. The rate of heat loss is proportional to the temp difference.
">That, of course, depends on the ambient temperature...
Of course not.
Nick "
I agree with that too. How much you can save by turning it down depends on ambient, but not whether you can save.
Yes, the rate of heat loss is proportional to the temp difference.
And mostly it depends on how well the body of water is insulated from the exterior. An outdoor tub in a cold climate will loose more heat over time than an indoor tub in an insulated room.
Under certain circumstances, for an indoor tub, the heat gain in the room can be seen as adding to the overall heat gain of your house. In other words, your paying to heat the tub, but the entrophy heat is released into the house and may be considered to be "free" heat, at least during the winter months.
Some people buy a spa to sit in it, relax, or pick their butt. Others buy it to calculate costs, contemplate physics, or just tell others they have a spa. But they rarely get in it.
That might cause a heat loss, and they would be up all night monitoring and figuring.
So, If I leave my spa out on the patio where it can freeze solid as a Popsicle, and then take a long time (months) to heat up, that doesn't depend on ambient temperature?
What I WAS saying, and you missed is:
THAT THE AMOUNT OF HEAT LOST DEPENDS ON WHERE THE SPA IS LOCATED ...... INSIDE ....... OUTSIDE ......... IN A SUNNY AREA ........ IN A SHADY AREA ......... IN A WINDY AREA ................. Did you get it that time, sweetheart?
That may have been what you thought or said, but what you wrote was:
... which implies that whether a spa uses less energy with or without a setback depends on the location, which is incorrect. Setbacks always save energy.
Nick
From snipped-for-privacy@zydeco.net Sat Dec 24 13:51:29 EST 2005 Article: 779602 of alt.home.repair Path: news.misty.com!yellow.newsread.com!news-toy.newsread.com!netaxs.com!newsread.com!newsstand.newsread.com!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!newsfeed.icl.net!proxad.net!64.233.160.134.MISMATCH!postnews.google.com!news3.google.com!border1.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!peer01.cox.net!cox.net!p01!fed1read06.POSTED!53ab2750!not-for-mail From: "Steve B" Newsgroups: alt.home.repair References: Subject: Re: calculating costs of a spa Lines: 50 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.2180 X-RFC2646: Format=Flowed; Original X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 Message-ID: Date: Fri, 23 Dec 2005 19:20:05 -0800 NNTP-Posting-Host: 70.189.229.58 X-Complaints-To: snipped-for-privacy@cox.net X-Trace: fed1read06 1135394354 70.189.229.58 (Fri, 23 Dec 2005 22:19:14 EST) NNTP-Posting-Date: Fri, 23 Dec 2005 22:19:14 EST Organization: Cox Communications Xref: news.misty.com alt.home.repair:779602
If you have to ask, you can't afford it.
Spas can be set to all sorts of settings. They can be set to filter for different amounts of time. They can be set to economy or standard, meaning that during economy, the heater only comes on during filter cycles. In standard mode, it comes on whenever the temp goes under the preset.
There is much argument/debate/discussion/hysteria over the advantages/disadvantages of leaving it on all the time, or leaving it where it will maintain a constant temperature. That, of course, depends on the ambient temperature, since a spa inside a house in a "spa" room would not cool down as quickly or as much as one outside. And then, there's the balance argument of: which costs more ....... to keep a spa hot, or bring up the temperature 20 degrees every time I want to use it?
My Catalinas heat up at the rate of five degrees an hour. When I change the water, I use pool water, as it is generally warmer than tap water, and when the solar is going on the pool, it is a lot warmer than tap water.
It is impossible to estimate the answer to your question. It is all intellectual mathematical masturbation.
It is what it is. If you want a spa, you will deal with it.
I love my spas, and spend more time in them than in the pool on a whole year basis.
A better quality spa will cost less than an El Cheapo from Homer's. They have better heaters, motors, and piping, which circulates the water better.
If you want one, get one, and fergeddabout the cost. If it makes your electric bill jump too much, adjust, and then if it is still too much, get a better job or do other things to increase your income.
HOWEVER my "spa" and I prefer to just call it my "tub" is kept at 101 degrees 24/7 year round....
I may save money by using setbacks BUT I know damn well the thing is ready to use ANYTIME day or night ... I was in last evening early and the wife used it after minnight mass
Actually my "tub" runs me about 20 bucks a month on average.... just not enough money to worry about...or enough money to try to regulate its readyness...
Ditto here. If I had to plan every time I would use it, and go out and turn it on and turn it off, I would forget more times than I did it.
People talk about chemical costs. I put two tabs of bromine in mine every couple of weeks. That's it. I guess we have the right kind of water. When I DO check the ph and stuff, it's right in there.
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