I'm looking for some advise from people who aren't trying to sell me something!
I'm with a non-profit organization which has a 35'x75', 110,000 gal indoor pool which needs a new heater after the 15 year old unit sprung a leak in it's heat exchanger. The old unit was massively oversize, so I'd rather not base sizing off of it. We're looking at sizes between 500K-750K BTU's depending on the unit and cost. Does that seem right? The old unit was 1.8 million BTU's and was definitely too much - they may have been using the pool to heat the room when it was put in 15 years ago.
Now we have a high-end HVAC system to keep our air temp ~83' year round and would like to maintain an 80' water temp. Our ventilation system also monitors humidity. The first 5 days without heat the pool temp dropped 1' per day until slowly settled out around 71' where it has remained. Temps outside have been 30' or so.
We have no limits on size or restrictions on plumbing/gas line placement or sizing.
We're looking for a natural gas heater with:
- - CuproNickel or better heat exchanger,
- - the ability to duct intake air - to keep the DE and chemicals from getting sucked in
- - exhaust through a side wall (4' or so from the unit),
- - high efficiency as reasonably economical
- - easy to maintain and trouble shoot
- - Longest serviceable life
Units we're interested in:
Low bid of the ones listed here - meets our minimum standards and should get the job done. Will it last? Sales rep not knowledgeable about maintenance long term. Said 'it needs no maintenance.' Sure...Pentair PowerMax / Laars Pennant
Positives: All the above, plus :85% efficiency, sealed combustion, low nox, about $10,000
Only one size available. We would likely need 2 for our needed max capacity - perhaps they could be staged as needed however. Seems to be more for residential use.Jandy/Zodiac? Hi-E2
Positives: All the above, plus: 'up to' 98% efficiency, vent through PVC, about $6K each
Expensive - but maybe it's worth it? Could be harder to maintain/easier to break fancy things. Can't find much info on the Raypak...Lochinvar Sync or Raypak/Rheem XTherm
Positives All the above, plus: fully modulating condensing combustion, Stainless Steel Heat exchanger, the Lochinvar 'features' smartSync controls ~$35,000
So - Which others should we consider?
What do you think about these units? Do any standout better than the others? Any you'd avoid?