Buying a pool heater

[PammyB]

I am looking to purchase a pool heater for my pool which is 18 by 36 feet ( 80000 litres) , its about 20 years old and it had a pool heater at some point but not since I’ve owned the house the past 3 years - we are in Quebec, Canada and want to use the pool ideally May to October, the coldest temperatures outside would be around 15 c ( 60 f) before we’d close it up for the season.
My question is , after going to some shops they are all telling me I need the most expensive thermopompe to serve my pool size , I just want to make sure this is accurate information before I spend the $7000 it seems it will cost to purchase and install. They are recommending a Nirvana thermopompe ( 120 to 140,000 btus) Is it possible to get something lower grade /priced and still have good results or should I absolutely invest in top of the line?

Thank you !

 

[PoolGate]

140k BTUS? Is that a heat pump? A heat pump is not going to get you all of May (maybe part) or any of October (not even September) in your climate. Can you get gas either natural gas or propane?

 

[PammyB]

we use the pool currently June to mid September with no heater at all so I’m not sure if that’s accurate?

 

[PammyB]

But not looking to use it in October just end of September and more comfortable early mornings and evenings in the summer!

 

[SJPoe]

We are in Mid-Michigan. Similar sized pool, roughly the same climate.
We have a Hayward 250KBTU Natural Gas heater. We open in Late April/Early May, and we closed last year in early October.
At the start of the season, heating the pool is expensive - you're looking at roughly 0.5F/Hour. It basically takes 3 days flat out. I figure it costs me $300 roughly to get it up to swimming temp.
With half the BTU, you're going to struggle to keep up with heatloss alone, let alone actually heating.

Rough math - 5BTU/sqft/Degree of Difference. If it's 40F outside, and you're heating to 80, thats a 40F difference = 200BTUx 650sqft = 130k BTU...even with a cover, thats essentially flat out to MAINTAIN temps.
Your supplier is right, 120-140 is probably the minimum you can get away with, and thats assuming your 140k Heatpump is capable of delivering 140k BTU at ambient temps in the 40-50F range.

 

[PoolGate]

I guess it depends what temperature you like. I can't swim in less than 90.

 

[PammyB]

Oh it’s not that cold here in the summer - will be coldest 60F when we would operate it and mostly much hotter and would not be heating to 90 but thank you for the info I understand we do need something that powerful , thanks!

 

[SJPoe]

FYI- I'd change the pool size in your bio to gallons, or people may recommend way more chemicals than needed. 80k litres is about 21k US gallons

 

[PammyB]

Thank you will do