Potetial pool owner in PNW

[PNW-pool]

I have a house under contract with a 24 year old, 30x15 rectangular inground, plaster pool located 25 miles east of Seattle (~100 ft above sea level ... so not in the foothills). Heater: 250,000 BTU Zodiac Legacy heater (natural gas). Filter: Pentair Tagelus with a leaking drain plug. Pump: Hayward 1.5 HP. The incandescent light (Swimquip 1) doesn't work and does not appear to be on a GFI

I owned a swim spa for about 12 years at a prior home in the area and loved it -- used it year-round. I've always wanted an inground pool ... but not sure if this will be a dream-come-true or a nightmare. I don't mind spending my time, elbow grease, and a "bit" of money to get the pool in good working order, but don't want a money pit. I'm somewhat handy but not a mechanic or electrician. I'm very interested in adding a retractable (or permament) pool enclosure for year-round use.

I'd love some input and advice ASAP on:

• Gas and Electric Costs to heat May-October (with no enclosure) ... with and without a pool cover
• Experience with year-round swimming and cost to heat with a rectractable pool covers like the Laguna sold by Pool enclosures and patio enclosures from Pool and Spa Enclosures USA | sunrooms-enclosures.com)
• Best (safest, cheapest, longterm) solution for dealing with the non-operating pool light. Is this a job for an electrician? Should I switch to LED? Does the pool need to be drained to fix this?
• How to winterize if my closing / taking ownership happens in early February
• Questions I am not asking but should be ....

 

[markdpratt]

If you have not already done so, you need to have a pool-only inspection done by a reputable pool inspector to insure you know of all the issues with the pool. And then obtain estimates from licensed and reputable contractors for the repairs that can be used in negotiating with the seller. At a minimum, I would require all safety-related items, such as GFCI protection, to be in place.
I will let others respond to your specific questions.
Good luck.

 

[SJPoe]

Heating costs are tricky, and depend on a lot of things specific to your installation. How efficient is the heater, how hot do you like the pool, how much sun does the pool get, how much wind, is it covered, etc etc etc.
I have a 36x18, inground in Mid-Michigan, with a 250Kbtu NG heater. No enclosure, just a solar cover. We pay about $9/Mcf for gas. Generally, I've always estimated it in my head at about $3, maybe $4-a-day to maintain a 85F-ish pool from May 1st through September 31st. It might be a little more or less, but I would bet that's pretty darned close.

Lets do some math

We do not swim year round because...well, Michigan...we barely brave the hot-tub in February for fear of hypothermia on the way in or out...
We generally open and turn the heat on late-April, and turn it off and close the pool once it starts getting consistently cool late-September (we dropped the heat to 65F October 9th this year, and closed the pool October 28th).

Looking at the gas bill and comparing August to May (not running heat in pool or house in August, so thats a good baseline), I used 24Mcf more in May. April was 9 more than August, and we'd not be using the pool heat then, but still running hot-water, cooking etc, so figure the difference is house heat, and that comes to about 30%, so I'm assuming that 1/3 of the extra is house heat for the purposes of this exercise...

Going through May, June, Jul, Aug and Sept (and 1/3 of October this year), assuming 66% of the delta against August is the pool, we see 18,12, 6,0,5,12 - so a total of 43Mcf over the period.
43Mcf is about $387. Call it $400 between friends.
Averaging that out over roughly 160 days, gives you about $2.40 day to maintain it. You can't buy a beer to drink by the pool these days for $2.50. And it's less than I thought it was, so I should probably petition the wife for some new toys...given how much money I'm saving...

That first month will be a bit eye-watering (getting 25000 gallons from a chilly 40-something to a wife-approved 85-ish takes a LOT of heat), but when you average it out over the season, it's not that bad.
We have a solar-cover, which probably reduces the heat-loss by as much as 70%, and that is on any time we are not actively using the pool. Thats probably worth every penny of the $200 or so we spent on it...not counting the reduction in leaves and debris getting in the pool etc.

As for the other items, if you take ownership in February, one would hope it would already BE winterized
Yes, I would absolutely consult a licensed electrician about the lamp/GFI status of the equipment pad - although there are some very knowledgeable people here that can probably also advise.

 

[PNW-pool]

Thanks for responding, Mark. My big question today is about montly operating cost (gas, electric, chemicals) under two scenarios: (1) as-is with no enclosure heating only peak season (May-Sep). (2) year-round use & heating with a retractible enclosure. The latter is a big capital expense that I can put a number on. The M&O for the pool is still (frustratingly) unknown. I'm trying to get data from the sellers but they're elderly, forgetful, and have several adult children chiming in on things plus communicating through two layers of realtors ! Even if I can get Puget Sound Energy gas/electric bills for the past 24 months, I don't know if that data is useful because I don't know how long the pool heater has been on fritz. I forgot to mention that it is currently not working and showing a heat sensor error code. Sellers have agreed to get the heater operational (or replaced) before closing and to fixing the leaking roof on the pool equipment shed. They are not agreeing to fixing the underwater pool light. We are in a tight real estate market here on the far-eastside of Seattle with low inventory so sellers can play hard ball.

I had a pool-only inspection done by a long-standing local company who are AquaTech builders and members of the APSP and United Aqua Group. In addition to custom residential and commercial design, build and remodels, they do maintenance, service and inspections. Inspection was $500 and seemed thorough. I got a printed report with equipment and deck specs & condition, concerns and suggested repairs - plus a zip file with about 30 photos. I am expecting the need to replace I am trying to do my homework on all aspects of the property including the pool, heading my late mom's advice: "Never buy a pig in a poke."

The timing has been challenging -- offer pending inspection on the property on was accepted 12/20 with 12/29 (got an extension to Jan 3) deadline to complete all inspections of the house, pool, and outbuildings (pool equipment shed plus a large detached garage/shop). There have been a number of DIY / jerry-rigged installations and repairs done on parts of the property and aging systems (house is 35 years old and pool is 25 yo). I'm learning as I go about the questions to ask and what "tires to kick" with a clock ticking. It's been challenging to get info from sellers (who are in their 90s) about pool maintenance history and operating costs.

*Sigh*

 

[PNW-pool]

Heating costs are tricky, and depend on a lot of things specific to your installation. How efficient is the heater, how hot do you like the pool, how much sun does the pool get, how much wind, is it covered, etc etc etc.
I have a 36x18, inground in Mid-Michigan, with a 250Kbtu NG heater. No enclosure, just a solar cover. We pay about $9/Mcf for gas. Generally, I've always estimated it in my head at about $3, maybe $4-a-day to maintain a 85F-ish pool from May 1st through September 31st. It might be a little more or less, but I would bet that's pretty darned close.

Lets do some math

We do not swim year round because...well, Michigan...we barely brave the hot-tub in February for fear of hypothermia on the way in or out...
We generally open and turn the heat on late-April, and turn it off and close the pool once it starts getting consistently cool late-September (we dropped the heat to 65F October 9th this year, and closed the pool October 28th).

Looking at the gas bill and comparing August to May (not running heat in pool or house in August, so thats a good baseline), I used 24Mcf more in May. April was 9 more than August, and we'd not be using the pool heat then, but still running hot-water, cooking etc, so figure the difference is house heat, and that comes to about 30%, so I'm assuming that 1/3 of the extra is house heat for the purposes of this exercise...

Going through May, June, Jul, Aug and Sept (and 1/3 of October this year), assuming 66% of the delta against August is the pool, we see 18,12, 6,0,5,12 - so a total of 43Mcf over the period.
43Mcf is about $387. Call it $400 between friends.
Averaging that out over roughly 160 days, gives you about $2.40 day to maintain it. You can't buy a beer to drink by the pool these days for $2.50. And it's less than I thought it was, so I should probably petition the wife for some new toys...given how much money I'm saving...

That first month will be a bit eye-watering (getting 25000 gallons from a chilly 40-something to a wife-approved 85-ish takes a LOT of heat), but when you average it out over the season, it's not that bad.
We have a solar-cover, which probably reduces the heat-loss by as much as 70%, and that is on any time we are not actively using the pool. Thats probably worth every penny of the $200 or so we spent on it...not counting the reduction in leaves and debris getting in the pool etc.

As for the other items, if you take ownership in February, one would hope it would already BE winterized
Yes, I would absolutely consult a licensed electrician about the lamp/GFI status of the equipment pad - although there are some very knowledgeable people here that can probably also advise.

SJPoe - this is exactly the kind of detail I'm hoping for. Real numbers from real pool owners in cool/cold climates. Thank you. Putting costs in beers per day (or here in Seattle, lattes per day) terms is music to my ears.

My potential pool is roughly 70% the surface area of yours in SF (450 v 650 sf) and maybe 60% of the volume (15,000 v 25,000 gal) so my numbers should be at or lower than yours -- all else being equal, which I understand is a significant caveat. Heater's BTUs (250k) and fuel type (NG) are comparable. If my info and math (therms to Mcf) are right. Your NG is cheaper than Seattle's. My bill is stated in therms; most recent was $1.13/therm (therms × 10.36 = MCF) so ~$11.80/Mcf compared to your $9/Mcf. So, I'm paying 30% more for NG.

I'm with your wife on wanting a warmer pool. Seattle weather is way more moderate than Michigan, so that bodes well for your numbers being conservative estimates for me. According to the googleverse, Seattle temps typically dip to freezing or below only 25 nights each year compared to 50-60 days in MI. Seattle typically only gets as cold as 20 °F (-8 °C) once a year. It is overcast 200 days/years. June can be colder and wetter than April and May (we call it June-uary). While the initial outlay for an enclosure is spendy, so is building a pool. This property has spaces I can AirBNB/VRBO and a pool would be a feature I can monetize. If it means I can get year-round for the next 20+ years at summertime heating costs, then I can justify it.

BTW - telling friends/family that I'm looking at a house with a pool reminds me of telling people what potential baby names. Every has an opinion and either a horror story or love story. A friend yesterday told me with 100% confidence that her good friend who has a vacation home in Scottsdale spends $100 per DAY every day to heat their pool. That might be the initial 40F to 80F cost -- or maybe they are doing an off-and-on routine only when they or guest use the house. I could not afford $36,500/year in heating costs! Another friend in suburban Seattle that actually owns a (really big) inground pool heats it from Mother's Day to end of September with an added cost of $500-700/month ($17-23/day), which is still more beers than I want to to spend. Hopefully an enclosure would help lower and flatten out costs -- but I wish I had real data!

 

[SJPoe]

SJPoe - this is exactly the kind of detail I'm hoping for. Real numbers from real pool owners in cool/cold climates. Thank you. Putting costs in beers per day (or here in Seattle, lattes per day) terms is music to my ears.

My potential pool is roughly 70% the surface area of yours in SF (450 v 650 sf) and maybe 60% of the volume (15,000 v 25,000 gal) so my numbers should be at or lower than yours -- all else being equal, which I understand is a significant caveat. Heater's BTUs (250k) and fuel type (NG) are comparable. If my info and math (therms to Mcf) are right. Your NG is cheaper than Seattle's. My bill is stated in therms; most recent was $1.13/therm (therms × 10.36 = MCF) so ~$11.80/Mcf compared to your $9/Mcf. So, I'm paying 30% more for NG.

I'm with your wife on wanting a warmer pool. Seattle weather is way more moderate than Michigan, so that bodes well for your numbers being conservative estimates for me. According to the googleverse, Seattle temps typically dip to freezing or below only 25 nights each year compared to 50-60 days in MI. Seattle typically only gets as cold as 20 °F (-8 °C) once a year. It is overcast 200 days/years. June can be colder and wetter than April and May (we call it June-uary). While the initial outlay for an enclosure is spendy, so is building a pool. This property has spaces I can AirBNB/VRBO and a pool would be a feature I can monetize. If it means I can get year-round for the next 20+ years at summertime heating costs, then I can justify it.

BTW - telling friends/family that I'm looking at a house with a pool reminds me of telling people what potential baby names. Every has an opinion and either a horror story or love story. A friend yesterday told me with 100% confidence that her good friend who has a vacation home in Scottsdale spends $100 per DAY every day to heat their pool. That might be the initial 40F to 80F cost -- or maybe they are doing an off-and-on routine only when they or guest use the house. I could not afford $36,500/year in heating costs! Another friend in suburban Seattle that actually owns a (really big) inground pool heats it from Mother's Day to end of September with an added cost of $500-700/month ($17-23/day), which is still more beers than I want to to spend. Hopefully an enclosure would help lower and flatten out costs -- but I wish I had real data!

$100 at $1.13/therm is roughly 9 million BTU...or enough to take 6500 gallons pretty much from freezing to boiling. I think they may have misplaced a decimal somewhere

 

[SJPoe]

One thing to note is that heating can be split into two parts - the initial heat to temp, and then the maintenance of that temp. Wall-o-Text incoming

The initial heat up is expensive - it takes a lot of energy to heat water. Over the season, this first week is probably 50-75% of my total annnual heating budget. Simplified, 1 BTU heats 1 Pound of water by 1F, so basically 8 BTU per gallon per degree. 40 degrees = 320BTU per gallon. 15000 gallons = 4.8M BTU. 250k BTU heater = 19.2 hours..assuming no loss, 100% efficiency (probably closer to 80% tho). My pool is 25k, and I went from 46 to 83, so 37F. Thats roughly 7.5M BTU - probably closer to 10M by the time you factor in efficiency etc...so around $100 just in the initial 'get it up there' run, not counting any loss we have due to the temperature outside that day and so on.

Once it's hot, it tends to stay hot, but you continually lose heat obviously. Heat a pot on a stove, it takes 10 minutes to boil. Take the pot off the heat, it takes an hour to cool...why ? Surface area...that's where the heat-exchange with the ambient environment occurs. The heat escapes at the interface, and convection in the water moves the water around until it all reaches equilibrium....and they told us we'd never use this stuff in real life. There is even a formula for it !!

So, generally, your 'loss' can be estimated as roughly 5 BTU per sqft of surface area per degree of difference per hour. We tend to ignore the inground part of the pool, although there will be SOME loss there, and more so with an above ground pool, but for this level of napkin math, it's easier to pretend it doesn't happen !! We're also ignoring Wind, air movement, humidity, rain, and a bazillion other things, because otherwise it all becomes impossibly difficult.

So 30ft x 15ft = 450 sqft, times 5 BTU = 2250 , times degrees of difference (we'll stay with 40F) = 90,000 BTU/hour LOSS. Assuming a 250K BTU heater, you'd need to run it about 21 minutes each hour to maintain your heat - assuming no wind, no cover and so on. A Therm is 100,000 BTU, so 0.9 Therms/hour, or about a dollar. I generally figure my heater costs me about $3/hour to run...so thats pretty much the same. So you'd be looking at a heating demand of about 8 hours a day, at roughly $3/hour, or $25 bucks a day - assuming no cover etc.

Throw on a cover of any sort, and you'll cut that 'loss' by a large degree - based on napkin math, I reckon my solar cover saves me 50%-70% in direct heating costs (you can guestimate the actual expected loss, versus the actual measured loss over a period, and the difference is the cover). Essentially an enclosure is a greenhouse, insulating the internal space from the outside, and allowing the solar radiation in. Anywho, lets assume you saved 80% with your enclosure.....your $25/day becomes $5/day, when the 'average temp' is 40F...and Seattle is above that for all but maybe 2 months of the year. At the end of this last season, my pool took almost 2 weeks to go from 90F+ to 65F, with the heater turned off and just the cover on with the overnight temps dipping into the 30s...

Your friend with the big pool might be giving you the worst case numbers - I doubt it costs them the same to heat it in May as it does in September, and $20+ a day seems very high to me... unless they have no cover at all, and just like heating the Seattle surburban atmosphere, or they are maintaining a spa the size of Rhode Island...

Basically, your enclosure turns your outside pool into an inside pool. You will still get SOME loss (through the walls of the pool, and no insulation is 100% effective), but it will be far less than a pool exposed to the outside air. Likewise, you'd get the benefit of being sheltered from the wind and rain, both of which will exacerbate heat loss. It'll be better than my solar cover, and WAY WAY better than no cover at all. I would expect the manufacturer should be able to give you some idea as to the insulation efficiency of their product...and I'd probably fudge whatever they say by a healthy amount

Your mileage absolutely WILL vary...but the laws of physics are pretty much constant, so you can come up with some reasonable estimates

 

[Newdude]

and I'd probably fudge whatever they say by a healthy amount

I also fudge the utility estimates by a healthy amount as the taxes, fees and surcharges can add considerable expense to the going rate. My electric bill is about doubled by then for example. I snicker every time I see one of those yellow tags telling me what the expected electric costs are, then double them.

If there are tiers of usage that will skew it even more if the device bumps you up a bracket.

I don't have street gas by me and I certainly don't know how your utility companies roll, just food for thought.

 

[PNW-pool]

I also fudge the utility estimates by a healthy amount as the taxes, fees and surcharges can add considerable expense to the going rate. My electric bill is about doubled by then for example. I snicker every time I see one of those yellow tags telling me what the expected electric costs are, then double them.

If there are tiers of usage that will skew it even more if the device bumps you up a bracket.

I don't have street gas by me and I certainly don't know how your utility companies roll, just food for thought.

There is natural gas service to this home, thankfully. I'm asking the sellers to pull their past 24 month histories. Puget Sound Energy provides downloadable data (both units used and $ charged) for gas and electric to current owners. Once I take over ownership, I will only be able to get 6 month averages of the prior owners' usage. Apparently the current owners did not heat the pool at all in 2023 -- so that will be great baseline data to have ... if they will be so kind as to give it to me

 

[PNW-pool]

Last night the deal went from pending-inspection to pending-financing ... so barring unforseen $naggle$, I will be a pool owner in a few weeks. This forum feels like a godsend and I am looking forward to living and learning from the collective wisdom here!

 

[s.hashemirud]

I have a house under contract with a 24 year old, 30x15 rectangular inground, plaster pool located 25 miles east of Seattle (~100 ft above sea level ... so not in the foothills). Heater: 250,000 BTU Zodiac Legacy heater (natural gas). Filter: Pentair Tagelus with a leaking drain plug. Pump: Hayward 1.5 HP. The incandescent light (Swimquip 1) doesn't work and does not appear to be on a GFI

I owned a swim spa for about 12 years at a prior home in the area and loved it -- used it year-round. I've always wanted an inground pool ... but not sure if this will be a dream-come-true or a nightmare. I don't mind spending my time, elbow grease, and a "bit" of money to get the pool in good working order, but don't want a money pit. I'm somewhat handy but not a mechanic or electrician. I'm very interested in adding a retractable (or permament) pool enclosure for year-round use.

I'd love some input and advice ASAP on:

• Gas and Electric Costs to heat May-October (with no enclosure) ... with and without a pool cover
• Experience with year-round swimming and cost to heat with a rectractable pool covers like the Laguna sold by Pool enclosures and patio enclosures from Pool and Spa Enclosures USA | sunrooms-enclosures.com)
• Best (safest, cheapest, longterm) solution for dealing with the non-operating pool light. Is this a job for an electrician? Should I switch to LED? Does the pool need to be drained to fix this?
• How to winterize if my closing / taking ownership happens in early February
• Questions I am not asking but should be ....

I live in Seattle and I only run the pump 24 hours to avoid freezing and so far worked!
The highest Gas bill for us who keeps the temperature about 82-84 when we swim(3-4 days in a week) was around $250

 

[s.hashemirud]

Last night the deal went from pending-inspection to pending-financing ... so barring unforseen $naggle$, I will be a pool owner in a few weeks. This forum feels like a godsend and I am looking forward to living and learning from the collective wisdom here!

I forgot to mention that I don’t cover the pool at night then it can be different for you if you have one