The only way you can make an educated decision in regards to the system you pool builder is recommending would be to talk to someone that has the same system. If your pool builder has used this system before on an indoor pool, ask to see it and talk to the homeowner or company that he installed it for. Propane is a very expensive way to heat your pool. No matter what type of heat source you use, you need to use a pool cover. Even a simple solar cover will act as a heat cap and cuts down on the humidity factor tremendously.

Your PBer is not far off on the proper way to condition your indoor pool. In fact, done right should run you more. You can choose a cheaper way and pay in comfort, replacement and damage later. Although this doesn't apply to you since yours is detached but, many code enforcement officers now require humidity control to pool areas attached to homes due to excessive humidity causing mold and ultimately destroying homes.

The packaged heat/ac/dehumidify units are the best way to go since they are capable of heating the space (somewhat) dehumidifying, and cooling the space (sometimes while dehumidifying) in the summer. If you dont think that will be necessary, be prepared to add considerable ventilation as your structure in the summer will feel like a sauna.
One of the advantages of all the operations mentioned is that while it is operating, the heat generated by the compressor(s) can be rejected to the pool water or space thus heating one or both.

Due to your climate, (I used to install these in NY) you will probably require additional heat besides a packaged unit to serve your pool and meet the pool and room temperatures desired. The main reason for this is the air temperature must be maintained at 2 degrees minimum above the pool water surface temperature. (Thermal dynamics, cold always migrates to hot). This is to reduce evaporation which again ends up being excessive humidity in the indoor pool area wreaking havoc on materials and requiring upsizing for dehumidification. Normally the way to achieve this is adding a sealed combustion boiler or if not able an outdoor boiler to heat a coil on the discharge air of the packaged unit raising the discharge air temp to heat the area. To go a step farther, radiant heat tubing in the pool decking area is a great idea and offers the following advantages; warm comfortable floors, needed additional heat for room, dryer floors for safety and icing around perimeter windows, slab and walls are eliminated.

My advice to you is check with an experience heating or mechanical contractor that has done such a thing and make sure that a proper heat loss is done and all the calculations are taken into account accurately.

I added a link to give you an idea about equipment required.

Hi donaldv and zl700
Thanks for the info. Donald; good call on contacting those references. I didn't mention it in the original post but a solar cover will be used as well. zl700; thanks for the link. The structure can open fully in the summer so I won't need A/C. I considered radiant heat in the decking but a plumber friend as well as a concrete friend I mentioned it to both said the expense would be HUGE! They also thought the coils would be too deeply set in the concrete to make any difference; I was told somewhere in this whole process that the deck thickness should be 4".
My husband knows 2 HVAC guys through his contacts and will put me in touch w/ them this week. I'm willing to use whatever heat source(s) is/are necessary w/i reason to do this right so I'll continue to take advice from you guys! Just remember, I'm a poor swim instructor w/ 6 mouths to feed, a kid in college and regular bills to pay!!
Thanks again
Joanneswimsct

Shoot me an email-I have a resource you may be interested in.

Actually its not that expensive, all things being relative on pool building. You can find companies online that design the layout and sell the tubing. With regards to your plumbers comment, he is way off on the not working thing. Find a HVAC guy that knows radiant and you will be on the right track. Bit of advice, explore the radiant well before discounting the idea as, you cant go back later and install. 4" of concrete with rebar and ground along with perimeter insulation is key to a good install. Trust me, if it didnt work, my former garage, basement and snowmelt on my concrete driveway would have been a great disappointment in subzero New York temps if radiant in a concrete slab didnt work.
Try going to www.heatinghelp.com and you can not only find a radiant professional in your area but, get any questions you may have about you pool heating, radiant & ventilation answered.

FYI, radiant works best in a slab of that thickness and performs best with that type of medium as its mass. If you were considering a high efficiency boiler and wished to heat the water this way then it is simple to use a heat exchanger for the pool and now your setup for radiant. Here is a link to see what I mean:
http://www.triangletube.com/HeatExchangers/MaxiFlo/HEMaxiFloOverview.htm
http://www.triangletube.com/CondensingBoilers/PrestigeOverview.htm

Thanks everyone; keep the ideas coming!
Robindigo, I'll email you to get that info. zl700, thanks again for you insight. I'll check those sights as I feel the need to educate myself further.
Joanneswimsct

Joanne, I am so glad to see your post and the responses. We have the pool built and the structure and have been working with our HVAC fellow in trying to come up with the best system. My husband came home today with information from the Dectron rep and so far, our HVAC fellow thinks that is the way to go. This is getting much more expensive that we had anticipated, but we want to do it right. I'm glad radiant heating has come up as we still have the chance to do that.
Any more information on anyone who has used the Dectron and also on the radiat heating would be appreciated by me also.
zl700, your information has been very helpful and I was glad to see you linked to Dectron as that is what we will probably will be using.
Joanne, good luck...I think it will all be worth it in the end.
Jeanie

The challenge you are going to face is you are dealing with trying to heat an uninsulated structure and there are tremendous losses through the exterior skin. Sunny days will probably be fine due to heat gain, but overcast days will be difficult. Over the Christmas break my family went to Schlitterbahn in Galveston, they enclose almost the entire waterpark during the winter. I had my doubts as to how comfortable it would be, but it was actually very nice! The enclosures were just heavy plastic sheeting and coated canvas, but the interior space was comfortable despite the temps being in the 40's while we were there. They did have some HVAC units running in certain "rooms", but much of the park was heated by free-standing propane heaters. They got the job done quite well. Portable space heaters like they use there may be worth considering, you can move them around to focus heat in certain areas. The Schlitterbahn heaters have hoods that did a great job of focusing the heat downwards. I imagine they're reasonably priced, but of course you'll have to deal with refilling tanks when they get low so there is some maintenance involved.

Assuming that your pool enclosure envelope is relatively tight since it is being built as a permanent structure, I would discount the use of un-vented temporary heaters. I strongly recommend not subjecting the pool users to the combustion byproducts of gas, especially carbon monoxide, the invisible deadly one. If your pool is connected to the house, the complications are compounded as you will ultimately be exposed to CO even that much more.

Just a comment on radiant (in-floor) type heat. Usually radiant floor temps are designed up to 78 degrees Fahrenheit max in order to be most comfortable for our feet but also when used on hardwoods, avoiding damaging the floor surface. In the case of a pool enclosure with air and water temps are elevated; it is no problem and recommended to design the slab temperature up to 85 degrees Fahrenheit under the most extreme outdoor temp. Make sure your radiant guy understands this as it affects tubing design, controls and probable supplemental heat required to maintain that ever important 2 degree higher air temp than pool water to reduce evaporation.

Agree with zl700. Conditioning air in an indoor pool is not easy or cheap if done correctly. Indoor air quality is challenging with indoor pools due to high humidity and poisonous gases from the pool (chloroform). The air in the room should be exchanged with fresh outdoor air at least once per hour and preferrably twice per hour. This also drives energy cost as the outdoor air needs to be conditioned as it is brought into the living space.

Not trying to deter you from indoor pools, but if the space is adjacent to living areas of the house and is going to be airtight, these things should be considered.

Humidity is also a challenge, but if the air is exchanged and conditioned every hour or so, then humidity should not be a problem. Your PB estimate of $25K sounds reasonable, if the desired effect is a comfortable indoor pool environment that is free of high humidity, condensation and smells.

Any other lower cost conditioning methods will likely result in an environment that will not provide satisfactory comfort for the occupants in the long run.

Hope this helps.

Hi gang
Thanks for all of your input. FYI: the structure will not be attached to my home. It is not air tight, either, because of the materials and design. That helps in that I'll be getting nice fresh air but it'll hurt in that it'll be nice fresh COLD air! I don't mind paying the $ for a true HVAC system if that is really the only way to go nor do I mind paying for heat on extremely cold days. For the time that it's sunny and over 30 degrees, I'll get up to around 70 inside w/o an additional heat source due to the passive solar energy so I'll save $ on those days.
For those of you offering input, I strongly urge you to check out the enclosure at www.libart.com. It is unconventional so a normal HVAC system for a traditional indoor pool set up may not work under these conditions. Keep in mind that the enclosure will open/close on a track plus it has windows w/ screens and sliding deck-type doors at both ends for additional ventilation (for those hot sunny days). I gal I've talked to in TX has the same structure. She heats w/ a large Home Depot-type blower as seen at mega stores in the entryways. She spends very little for heat and she is in the pool w/ lessons 8 hours/day. The day I talked to her it was 30 degrees outside but real sunny. It was 90 under the enclosure w/o added heat and she had to open her windows. She has had her structure for one year and has not had any problems w/ mold, condensation, fog, poor quality air or huge heat bills. I'm stumped! She said her highest fuel bill was $200 for the month and that was when they had a run of cloudy cold days as well as about a foot of snow. I know TX has a different climate than CT but I was still surprised at what she told me. How does that compute w/ what I'm hearing about an HVAC system?
This is way too confusing!
Thanks again...
Joanneswimsct

Quote:
"Assuming that your pool enclosure envelope is relatively tight since it is being built as a permanent structure, I would discount the use of un-vented temporary heaters."

Your assumptions are incorrect, read the first post again. There is a description and link to the structure being used. It is sliding panel system that runs on tracks, they are notoriously poorly sealed. You can't think of this in terms of heating a normal sealed space, the losses are far too large for that.

joanneswimsct -

Just checked out the libart website and have a better understanding of your application now. With this structure having the ability to vent and introduce fresh air by manual means, concerns of indoor air quality are diminished. A portable heater will work fine during the cooler months. Fogging and condensation will sometimes happen as the outdoor temperature and dewpoints change, but when the structure is opened, the fogging/condensation will eventually clear, especially if the portable heater is on.

Hope this helps.

Joanneswimsct,

I checked the website and the enclosure looks nice

The outdoor design temp difference between CT & TX is considerably different. Not having done a heat loss though, I would venture to say the heat/energy required in CT versus TX would be 2-3 times.

Question to check with your supplier though-

What is the snow load rating?
What happens to all the snow as it melts from warmth inside , drip through or refreeze on surface and in tracks?

If it refreezes, will the ice cause damage and will the structure even open with snow or ice on it?

Just a comment on the heat issue, I would still stay away from unvented heat, non-sealed combustion units. They won't last long with the chemical exposure. But still most important the CO exposure. a comparison-people have died in camping tents with a small propane radiant heater, and tents are pretty loose ventilation wise.

Hi guys
Thanks for looking at the structure more closely; now you see what I've been talking about!
zl700: the structure was built for a snow load of 40 pounds and it will handle winds up to 120mph. Here in CT I'll need a snow load of 30 and a wind rate of 100 so I'm all set on that. (The building was manufactured to MA code.) As far as snow and ice, if it is too cold to swim outside, we stay inside; to heck w/ the snow and ice!! No need to open the structure on days like that. If it gets warm inside on a cold day all I need to do is open any of the windows. I have talked w/ countless owners and so far none of them have had any damage to the building or track due to snow/ice. My structure will be built on a freeze (frost?) line foundation so no chance of the track or deck warping/cracking/getting out of alignment.
Trhought: I was very close to just using a few of the vent-free propane heaters as many of the owners are curruntly doing the same. I'll bet, however, that none of them, except the gal in TX, is in their pool 8 hrs/day 6-7 days/week running a swim academy. I'm assuming they all just pop in the pool every now and then just because they can. I'm going to need some source of heat that is efficient (HA!), safe, and comfortable for long stretches of time in the pool. I currently run my lessons out of a school pool who's air temp is a disastrous 68 (their pool pack is broken) and the H2O a chilly 80. I'm in the pool for 6 hours and have resorted to wearing a full body 3mm wetsuit. I stay quite warm but some of the smaller kids are chilled to the bone by the end of their 30 minute lesson. Since the first rule in learning to swim is relaxing, I'll need the whole set up to be comfortable for all of my students. It sounds as though I should just pony up the cash and do the whole HVAC system w/ radiant heat for the air, pool as well as decking??? The system at $25K will cost more than the actual pool!!!! Should I prepare for the HVAC system but try out the small heaters the first winter and if they don't work I can then complete the installation of the HVAC or doesn't it work that way? Kind of like installing duct work for A/C in a house but not having the $ to complete it until years later??
Again, any and all offers of help are much appreciated!! (And you can all dream of swimming at my place while you're pools are all closed up tight for the winter!!)
Thanks!
Joanneswimsct

Joanneswimsct Thats what I was thinking also. Try the portable heater(s) first and see how they work. With the structure not being airtight and the ability to vent whenever needed, the portable heaters may work just fine. If the desired comfort for 6-8 hours at a time is not achieved with portable heater(s), then an upgrade can be done as a retrofit.

I would rough-in the poly-pipe for the radiant heating floor when the concrete decking is being installed. This way if radiant heat is desired later down the road, the concrete decking will not have to be re-done. Roughing these pipes in ahead of time should not cost that much. It will just be the cost of the piping plus labor to set the piping prior to concrete.

Regarding conditioning the air, this could be done as a retrofit also. With a structure such as libart is offering, a residential packaged heating and cooling unit could be installed easily after the structure is placed and in use. These units are typically installed in older homes or new/existing mobile homes where extensive ductwork is not desired and inside space is minimal. With the libart system, I would think minimizing ductwork would be desireable as any ductwork will take away from the appearance of the structure since there is a lot of glass and not many places to hide the duct work. This should be a lower cost option than the $25K system that was offered and should still condition the air nicely as long as appropriate amount of outdoor air is introduced to keep fresh air in the space. Not sure how tight the libart systems are, but introduction of some fresh air will be needed, either by manual or automatic means.

The $25K system will likely introduce fresh air and control humidity and temperature levels automatically and very comfortably. Conversely, the residential packaged unit, would require a little more manual intervention to control humidity, temperature and outside air mixing. There are several products in the HVAC industry also that can be fitted to the residential packaged system that would automatically introduce fresh air also for a little more money. These devices are called energy recovery units and will mix outdoor air with indoor conditioned air to help minimize energy losses but still introduce fresh outside air.

Hope this helps.

Thanks Trhought
I have a few calls out to local HVAC people and found a Dectron dealer in the next town over. The Libart structure will turn over the air w/o extra help needed. I was told that we could save some $ in labor costs if my husband and I run the tubing for the radiant heat in the decking. I'm glad to hear you say we could rough in the project and give the less expensive way a try. If it doesn't work I guess it wouldn't take much to re-fit it w/ the HVAC system.
Thanks again everyone for all of your help. I'll keep you posted. Tues we have our pit and perk tests; next step is a survey of the property if the pit/perk goes well. Then it's a trip to planning/zoning for a variance. Oh boy!
Joanneswimsct