Hi there everyone, been lurking around here for a few weeks and was hoping you guys could give me some advice. We live in Oklahoma, so we get both hot and cold extremes in temperature. We've got a 1800 sqft ranch style house, built in the 60s, that's had little to no upgrades on it. I'm planning towards the end of this year to do a total, gutted renovation on the house, from top to bottom, with the aim of meeting passiv standard. Originally, we had planned on adding a pool in our back yard (about an acre of space), and doing it after the house. However, we've decided to do the pool first, since we don't want all the heavy machines etc to be getting close to the new house after it's done on their way to the backyard. We figure it'll be easier to finish the pool first, then do the house. We want to be able to use the pool year round, when it's 100 degrees outside and when its 10 degrees outside. So we're going to build a detached pool house for it. The pool won't be huge, about 12x28, with the building itself being about 20 x 50. So about 1000sqft, just a simple rectangular building. So my question is this: would it be possible to build the pool and its enclosing poolhouse and have it be net-zero? I've given up hoping we could have it be passiv, but I would love it if we could at least get it net-zero. It will have a very sunny western facing side where we could throw up a bunch of PV panels. What we would need then is enough energy to 1) heat the pool during the winter, 2) run the HVAC/humidifying system for the building, 3) run the automatic pool cover, 4) operate the lighting, 5) operate the other pool mechanical systems. Do you think it could be done and keep the structure itself net-zero? Many thanks for any advice you can give!

Is it going to be an ICF pool?

that's the plan, yes.

I don't believe it will be possible. I operate an indoor commercial pool and let me tell you it's one MAJOR headache and costly operation.

Pool pumps have to run/circulate sometimes 24/7 and can be dialed down when not in use but it's a high energy draw.

The other major problem I encounter with indoor pools is HUGE moisture problems. The Pool Pak system that regulates and removes moisture from the air is about $30,000 piece of equipment and requires constant maintenance.

Guaranteed mold growth within the walls and tons of moisture issues around electrical outlets, ceiling areas and doors. During winter the windows sweat so much moisture that puddles of water form on the ground in front of them. The hardware rusts and needs to be replaced.

Indoor pools are for the rich and famous who have people they pay to monitor the pool and pay the electric company huge electrical bills.

Ask anyone who has to run an indoor pool and they will tell you what it takes to keep it running properly and the moisture problems they face constantly.

I expect that a private pool can spend most of its time covered, removing much of the moisture problem. Less use also means less pumping needed and less chlorine. Reminds me, I should put down the computer and scoop the leaves out of the pool....

I know very little about this but there was an interesting report (only in German sadly) on the Passivhaus Institut's website about a case study for applying Passivhaus-Standards to indoor pools:

http://www.ig-passivhaus.de/upload/2015_12_15_Passivhaus-Hallenbad_Bamberg_Pressemitteilung.pdf

That study is a lot different because it deals with a huge, public pool in a spa type building. The OP wants a small indoor pool that could go in his backyard, so I don't know how much of it would be relevant, but if they can make a massive indoor pool passive then surely you could do it with a 50x20 one room building.

And yes, if you use a pool cover then the moisture issue becomes almost null and void. Also you could use a salt based pool (growing in popularity) as opposed to chlorine.

We have worked with several indoor pool scenarios. The pool represents a relatively enormous heat sink at moderate temperature. It also presents a humidity load, when not covered. The energy required to maintain the pool is nearly entirely at the surface an insignificant when in the envelope. However, the chemicals and fresh water required required significant de-humidification requirements in all but the driest climes.

I know a fella with such an arrangement and he says its great in Phoenix...