Multiple heater plan help

BurbankBrian

Member
Mar 20, 2017
7
Burbank CA
Hello TFP, this is my first post. We're building a 14x30 pool with integrated/spillover spa in Burbank (Los Angeles) CA. One of our top priorities is keeping the pool comfortable year round (85-90 F?) as efficiently as possible. Ideally we would keep the pool at or close to temp all the time and heat up the spa on an as needed basis. The pool will get full sun most of the day, and of course we'll use a solar cover when not in use. The PB has specified a JandyJXi400 as our main heater. I am thinking we should supplement this with at least one other heater, either heat pump or solar. The roof we would put the solar on has a straight southern exposure. The heat pump seems like it would be a good choice here as we tend to be above 50 in the daytime throughout the year. Would doing all 3 types of heat be crazy? I don't mind spending more now to avoid huge gas bills in the future. Thanks for any insight you may have.
 

yankeelawyer

Bronze Supporter
Jun 21, 2016
118
Virginia
We also considered installing both a heat pump and a gas heater to minimize monthly running costs. In Virginia, the pool really needs to be closed over the winter because the temps range between 18 and 40 degrees for a few months (though this year we had a very warm winter). But, the goal was to be able to extend the season so we could swim April through the end of October, including outdoor temps averaging 55+. Also, I wanted to be able to maintain a fairly constant temp every day during swim season.

We ended up opting for a heat pump only, reasoning we could add a gas heater later if it turned out to be necessary. I am so glad we did, as the heat pump alone so far has been perfect. We opened the pool on Wednesday with water temp at 61 and set the heater to 80. Within 24 hours it was 72 and within 48 hours it reached 80. This was with day time temp of 55, very over cast, and nighttime temps in the low 40s. The water temp rises about 1 degree every 45-60 minutes during the day when temps were in the 50s (again, without sun). Our pool is 30,000 gallons (20x40, from 4 to 6 feet deep) and does have an autocover. We have been closing the cover at night to reduce heat loss.

We do not have a spa and during the summer pool temps can reach mid 80s or 90s from the sun /heat alone, so I don't think the quick heat ability of a gas heater ultimately would be important for us. Gas can be prohibitively expensive in our area and I hated the idea that someone could accidentally turn the heat on high and run up a massive bill. Even if we ran our heat pump 24/7 for a month the bill would be hundreds, not thousands, of dollars. In addition, our heat pump has a chiller feature that can be used to cool the pool in the hottest months.

When I looked into which type of heater to buy, many said gas is the only way to go. But a lot of the folks I asked also had no firsthand experience using a heat pump and consistently said it could not be used to extend the season because they perform less efficiently in cooler temps. As I said, ours is doing great with day temps in the 50s and nights in the 40s in completely overcast and rainy conditions -- but I think the autocover helps a lot as well. We also opted for a large unit (the RayPac 8350 / 133k btu), which is one size larger than the minimum needed for a pool the size of ours.

One downside to the heat pump is that it cannot raise the temp as fast as a gas heater. I also think you may be able to reach higher temps with a gas heater. We only set ours to 80. I am wimpy about cold water but I think 80 or above is fine for swimming, fwiw.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,882
Tucson, AZ
In CA, with astronomical utility rates, you really don't want to run a heat pump all the time unless you have a money printing press in the basement. Do you have solar electric? There is a company here in Tucson that does solar water heater installation, but they also offer a very high-end (aka, lots of $$$) solution - they install solar PV on the roof and then run a heat pump using the electricity generated from that. The obvious advantage is that you get the power from the sun running a heater with a much smaller footprint than conventional panel or coil water heaters. The downside is it's about 2X the cost of a standard solar water heating installation. But, if there's excess power, you can also run your pump off of it and that saves you the utility fees for running the pool.

Anyway, if I were in your shoes, I'd do gas for the spa and solar on the roof to keep the water warm...heat pumps in CA just sounds like a really bad idea....
 

yankeelawyer

Bronze Supporter
Jun 21, 2016
118
Virginia
I am not an expert on CA utility rates but when I lived in LA a few years ago it was about 13 cents a kilowatt. Current rates in my area in Virginia are about 11 cents a kilowatt, and the cost to use propane to get the same heating would be 10x the cost of electricity for a heat pump. Almost everyone I spoke to when we were looking advised to get the propane heater due to cost savings but I am just not seeing how that works out.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,882
Tucson, AZ
The people you spoke to may be confusing propane with natural gas. Propane has to be delivered and stored on site and is very expensive. Natural gas is delivered via utility much like water and is significantly less expensive. Where I live, natural gas is 1/3rd the cost of electricity on an equivalent unit of energy basis. So basically a heat pump for me would cost 3X as much to run as an NG heater.

CA rates can easily go as high as $0.40 per kWh in some areas as the rates are tiered, seasonally based and the baseline level of energy use that the tiers are compared on is ridiculously low such that no modern home could achieve it without a serious solar PV installation.


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A165fun

Well-known member
Sep 5, 2016
91
New tripoli, PA
My electric rate in eastern PA is less than $0.10 usually so I would do a heat pump if I wasn't going to have a spa. I think I'm stuck with propane


Spring 2017 new build in PA ! //// Pool on a big hill //// IG SWG 800 sqft +100 sqft sun shelf + 50 sqft spa. //// All Jandy Pro series equipment (help me choose which models !) //// SGM River Rok or Diamond Brite (help me choose!) //// Stamped Concrete, Pavers, or Stone (help me choose ! )
 

BurbankBrian

Member
Mar 20, 2017
7
Burbank CA
With the integrated spa I have to have a gas heater to bring the spa up to temperature quickly. According to the Hayward calculator (which I know is trying to sell me a heat pump) keeping my pool at 90 year round with my local utility costs (and keeping it covered) would be $2,202 with the heat pump or $4,303 with natural gas. If keeping a warm pool is a top priority would it be reasonable to have gas, solar tubing, AND heat pump?
 

yankeelawyer

Bronze Supporter
Jun 21, 2016
118
Virginia
With the integrated spa I have to have a gas heater to bring the spa up to temperature quickly. According to the Hayward calculator (which I know is trying to sell me a heat pump) keeping my pool at 90 year round with my local utility costs (and keeping it covered) would be $2,202 with the heat pump or $4,303 with natural gas. If keeping a warm pool is a top priority would it be reasonable to have gas, solar tubing, AND heat pump?
I would compare the cost of installing all of that equipment upfront (and average running cost) versus the cost of running gas only. Personally, given that you have a spa, I would be inclined to start with gas and solar and see how that goes. You can always add the heat pump later. Just make sure you the electrical setup is sufficient (i.e. available double pole 50 amp breaker and wire of sufficient gauge).

Also, have you chosen a pool interior finish? Darker colors absorb heat better than white plaster.
 

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