Heat Pump v. Gas in Philly

redroark

Member
Jun 10, 2015
6
Philadelphia, PA
Folks, I have been a devotee of TFP for the last six years of owning my ancient Sylvan pool in the Philly area, but now I need help. My wife and I have finally decided that life is too short for an unheated pool. Our pool is heavily shaded and only gets sun part of the day anyway. As a result, it is frequently too cold for adult comfort even in the dog days of summer. Night swimming is almost impossible. We'd also like to extend the swimming season from April/May to September/October. Currently we are June-August only.

We are now looking to put in a heater. Gas would mean paying someone to run gas to our mechanicals (no estimate yet, but it's probably 75 feet). Electric is already there, obviously. I'm really struggling to understand when one is cheaper than the other. What are the factors? Who has had good/bad experiences with one or the other?

Thank you all in advance! This board is amazing and has saved my pool many times.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
11,838
Northern NJ
See...


Pentair has a calculator that shows you the difference in economics...

 

Newdude

Well-known member
Jun 16, 2019
1,675
NY
Gas would mean paying someone to run gas to our mechanicals
Super easy to DIY if you have the gas hookup already and your flow can handle it. The yellow pipe comes in 100 ft sections and uses a sharkbite like connector that you just push the ends together. You can dig a trench by hand for free or rent a machine for a half day if the ground is difficult to dig. Dig the trench, place the pipe, backfill half, lay caution tape and backfill the rest. Then just pay the skilled labor for the skilled labor part.
 

wireform

Silver Supporter
In The Industry
Aug 15, 2017
614
Spring Valley, NY
I say if you want to heat and want to really enjoy go with gas. Heat pumps when they work are slow. In the shoulder season heat pumps will struggle, gas to me is a no brainers, cheaper to run and faster to heat.Get bigger then what you need and you'll never look back. Be careful what brand you buy as not all brands offer warranty for DIY installs.
 
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jseyfert3

Bronze Supporter
Oct 20, 2017
499
South-Central WI
What is your price per kWh, including all distribution fees and taxes, and price per therm, including distribution fees and taxes? With these I could help you estimate which is cheaper to operate, which would help you decide if running a gas line is worth it.

For me, gas would definitely be cheaper. And I'm in the midwest which has some of the lowest electric rates in the US. I'm assuming you have natural gas at your house, propane is a different matter.
 

jseyfert3

Bronze Supporter
Oct 20, 2017
499
South-Central WI
Pentair has a calculator that shows you the difference in economics...
For me, gas would definitely be cheaper. And I'm in the midwest which has some of the lowest electric rates in the US. I'm assuming you have natural gas at your house, propane is a different matter.
I tried the calculator and it did indeed confirm a negative savings for running a heat pump vs gas for my particular cost per kWh/therm, for a 470 square foot pool located in Milwaukee (they only had Milwaukee or Green Bay) maintained at 85 °F. I was a tad skeptical at first that a calculator by a manufacture of a heat pump would actually tell you if a heat pump didn't make sense, but it appears it does. Even breaks it down by the month. Essentially it broke even during the summer, when you use hardly any heat, and lost money in spring and fall. Which is exactly what I expected for a decent COP air-source heat pump and my utility costs.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
11,838
Northern NJ
Yeah, the Pentair Heat Pump calculator does pretty honest math if you give it the correct costs. You need to give it your fully loaded gas and electrical costs if your provider charges separately for distribution or delivery fees.
 

wogster

In The Industry
Apr 30, 2018
114
Toronto, Ontario, Canada
Super easy to DIY if you have the gas hookup already and your flow can handle it. The yellow pipe comes in 100 ft sections and uses a sharkbite like connector that you just push the ends together. You can dig a trench by hand for free or rent a machine for a half day if the ground is difficult to dig. Dig the trench, place the pipe, backfill half, lay caution tape and backfill the rest. Then just pay the skilled labor for the skilled labor part.
I think the best DIY for this, is to get the heater in place, all the plumbing done, then you dig the trench for the gas line, the gas company will know how deep and what kind of material goes around the pipe proper. A licensed Gas fitter comes in, lays the pipe in the prepared trench, , and hooks up and starts the heater. You finish the first part of the backfill while the Gas guy tests and starts the heater, then they leave, you finish backfill and restore the landscaping. You save a big chunk of money while keeping your insurer and the city and state. happy.
 

Newdude

Well-known member
Jun 16, 2019
1,675
NY
I think the best DIY for this, is to get the heater in place, all the plumbing done, then you dig the trench for the gas line, the gas company will know how deep and what kind of material goes around the pipe proper.

The codes here use thicker pex like pipe, minimum 18" deep. It lays right in the hole and being plastic, makes easy turns without having to splice it. If you do have to splice it, they use push fittings that are expensive but take 9 seconds to hook up. No special kind of fill needed, but of course codes elsewhere would/could be different. Ask the plumber/HVAC/furnace person that comes for the quote how they need it done.

The point was to not have to pay the skilled labor price for the gruntwork. Most installers would rather have 3 easy jobs than spend 3/4 of the day loading up a trencher, trenching, installing and then packing everything up.
 

PoolBrews

Well-known member
Oct 16, 2019
103
Florida
Having had a pool in Michigan for 25 years, I would highly recommend that you go with gas. Regardless of the cost, there will be many times when a heat pump will not be able to keep your pool at a reasonable temp (82-85) in your area. When it does work, you will have to run your system for longer than normal times to maintain the temp. This means running your new VSP pump at at least 70% to provide enough flow to the heater. My MI pool was 42,000 gallons, and I had a 400K gas heater. We kept the pool at 86. Yes, this was a hit on our gas bill, but we were using the pool so it was worth every penny.

A gas heater will have no problem heating your pool - and will do it faster with less run time. If you have access to natural gas, do it. Propane is so much more expensive. Newdude is right - I had to run a line about 150' for my pool in MI. I rented a trencher and had it done in an afternoon. Just make sure you check to see what size pipe you need for the heater size and length of run.

When I was in Georgia, I had a heat pump, and in the colder months it was barely able to keep the pool heated. I had to run the heat pump 12 hours a day, and cover the pool at night. The pool was 18,000 gallons, and the heater was 140K btu.

Now I am in Florida, and my heat pump works great - no issues using the pool even in January and February (we are having a pool party today :)). However, the nights aren't as cold, my pool is only 6,800 gallons, and the heater is still 140K.
 

wogster

In The Industry
Apr 30, 2018
114
Toronto, Ontario, Canada
The codes here use thicker pex like pipe, minimum 18" deep. It lays right in the hole and being plastic, makes easy turns without having to splice it. If you do have to splice it, they use push fittings that are expensive but take 9 seconds to hook up. No special kind of fill needed, but of course codes elsewhere would/could be different. Ask the plumber/HVAC/furnace person that comes for the quote how they need it done.

The point was to not have to pay the skilled labor price for the gruntwork. Most installers would rather have 3 easy jobs than spend 3/4 of the day loading up a trencher, trenching, installing and then packing everything up.
Which is why I said to find out, dig the trench, have the gas guy drop in the pipe and connect it together. Some places require certain pipe and it have a certain kind of fill around the pipe, and some places require a licensed gas fitter to do anything related to gas.
 
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Newdude

Well-known member
Jun 16, 2019
1,675
NY
Yes. Good catch. I believe it has to be bonded on either end as well. I did a bunch doing side work about 5 years ago. It’s kind of fuzzy now.

but again, The local tradesmen/utility worker will know all the details and how much you are allowed to help to keep the costs down.