Houston indoor air quality

[flyingstudent]

I (along with my wife and 20 month old son) will be moving to Houston from Albuqueruque in the next couple of months. My son has moderate asthma. We will be purchasing a home (either spec built of fairly recent < 10 years old) and I was wondering about any suggestions that you would have when looking for a house in a humid climate for someone with a pretty sensitive respirotory system. What should I consider as we are looking at homes and what should I consider for mold inspection or testing?

Thanks

[teddy bear]

Mold leaves evidence of growth, but it can be cleaned up. Most Houston will have some mold growth over several years unless they have some method of humidity control.
The most critical issue is high humidity and wet spots growing mold. Monitoring the indoor humidity, maintaining less than 50%RHand eliminating any wet spots are most important. Maintaining <50%RH will require dehumidification during cool wet weather.
A pleated cloth air filter, merv 8 or 50% eff. is ideal to keep the heating/cooling system clean.
Ideally, provide 50 CFM of make-up fresh air ventilation to purge indoor accumulated pollutants and replace the consumed oxygen.
Checkout the Ulta-Aire whole house dehumidifier. It provides fresh air ventilation, dehumidification, and air filtering functions in one unit. A local a/c contractor will install/service this type of equipment.

[uktra]

I would check out one of the Pulte Builing America sudivisions (Do a search on DOE's Building America program). These homes control humidity much better than the average code built home. They also are more comfortable and have lower utility bills per sq. ft. than code homes.

[flyingstudent]

Thanks for the information.

I really like the idea of the Ultra-Air for our health and the health of home. I looked at some websites and I have a question. Why does this system require its own return, why cant it just use the existing return ducts?

I think they plan will be to move in and moniter the humidity conditions in the house and if there are any problems with mold, mites or wheezing invest in this system.

Thanks for the info

student

[teddy bear]

Using an independent return allows operating the Ultra-Aire without operating the a/c fan. When the U-A operates, the dry, clean air is delievered throughout the home via the a/c ducts before returning to the dehumidifier.
Get a good %RH meter from Radio Shack or Wal-Mart to monitor the %RH. High indoor humidity is a problem during cool wet weather. Use a good pleated cloth filter on your a/c and check the air handler for mold. Sounds like a good plan!

[dash]

Asthma;

1.Keep RH low.

2.4 or 5' media filter.

3. Bring in fresh to dilute Volatile Organic compounds.

4.UVC light above the A/C coil.

5. Test for duct system leakage,to prevent infiltration of air from currntly unknown places,attic .garage , crawl space,etc..Repair any leakage, http://www.aeroseal.com

[clean air]

Originally posted by flyingstudent
I (along with my wife and 20 month old son) will be moving to Houston from Albuqueruque in the next couple of months. My son has moderate asthma. We will be purchasing a home (either spec built of fairly recent < 10 years old) and I was wondering about any suggestions that you would have when looking for a house in a humid climate for someone with a pretty sensitive respirotory system. What should I consider as we are looking at homes and what should I consider for mold inspection or testing?

Thanks

I have two units one a whole house unit to clean the air.
Another a unit that mounts on your ductwork to clean all
of the ductwork as it is circulated. http://www.yourbestair.com/lindacox
http://www.demoair.com/lindacox

[airman1]

the biggest mistake you will make is relying on the agent that sells you a house and says ... dont worry about it it has a home owner warranty ... which is a polite way to say you wont get screwed util they are out of the picture ... so the best bet is EVEN IF it is a brand new house it will most likely (90%) have a low priced poorly installed undersized improperly zoned overly noisy system and then there is the venting insulation and radiant barrier ... each contributes to your whole house comfort and operating expense ... and if you dont discover problems and you move in and then the ashmas are worse ... you must be financial aolvent to fix it out of YOUR pocket ... see it all the time ... fix it all the time ... educate youself at http://www.centralcityair.com written on the Houston area ... whole house dehumidifiers are too often installed to cover up the lousy performance of a poor design ... in most cases they are not needed...

[Edited by airman1 on 11-10-2004 at 02:00 AM]

[cashcow]

Dash,

#3 - Bring in fresh to dilute VOC's.

Are fresh air systems used with success in Florida? I thought they would not work well due to the high humidity here.

[binford]

Buy a house with lots of tile or wood floors to start with.
Others gave you good advise too.

[dash]

Originally posted by cashcow
Dash,

#3 - Bring in fresh to dilute VOC's.

Are fresh air systems used with success in Florida? I thought they would not work well due to the high humidity here.

They need to be ERV's,Energy Recovery Ventilators.They use exausted air ,to lower the temperature and humidity ,of the incoming air.


Pricey,but they work very well.

[teddy bear]

Originally posted by dash

Originally posted by cashcow
Dash,

#3 - Bring in fresh to dilute VOC's.

Are fresh air systems used with success in Florida? I thought they would not work well due to the high humidity here.

They need to be ERV's,Energy Recovery Ventilators.They use exausted air ,to lower the temperature and humidity ,of the incoming air.


Pricey,but they work very well.

Best to bring in fresh air only with out intentional exhaust. Besides providing make-up air for clothes drier, bath fans, kitchen hood, and other exhaust air appliances positive pressure is desirable. In house positive pressure slows/stops moist outdoor air from entering can lights, wall cavities and insulation. ERVs transfer +50% of the moisture from the wet side to the dry side. During showers when outside air is drier than inside air, ERVs make the home wetter than make-up air only. They only function if the home is kept <50
% RH by mechanical means. An ERV changing air in a home without controlled dehumidification over a wet week, will make the home wet after several air changes. ERVs are justified for high flows of fresh air with continuous ventilation. They are mated to a dehumidification system to remove the missed moisute. The price of an ERV and whole house ventilating dehumidifier are about the same price. Its clear that we must keep the interior of our homes dry and aviod evem isolated high humidity conditions that will grow mold.

[flyingstudent]

Hello All,

Well I'm happy that this thread has prompted some interesting discussion. We have been in our new home in houston for about a week. In the last week the heat and air have been on a little bit each and on saturday we had the windows open in the afternoon. We have a smallish stand alone dehumidifier that has been running nearly constantly and keeping the RH retween about 50 and 55 %.

This is a new two story house with two hvac units in the attic (these are Goodman units which are apparently made here in houston). Although Goodman appears to have a pretty bad name on this board, it looks like the installation is pretty good for a tract home (mostly using flex duct), in comparison to many of the problems discussed here

I would like to get the HVAC system set up with bi-annual service/maintainance and I'm wondering if I should contact the company that installed the system and have them do the work for at least the first year (while everything is under warrantee from the builder) or if I should call a different company immediately to have to system independently evaluated (we did have a general home inspection) while they are doing the maintainance which could possibly void the warrantee. Son's allergies actual seem to be a bit better here then in albuquerque.

I'm thinking about adding a second stand alone dehumidifier for the second floor to make sure I have the capacity to always keep the RH below 50 - 55 percent.

The house has two 20 by 30 inch filters that are 1 inch thick. Are there thicker, pleated filters available that I could use (there is plenty of clearance in the filter holders) ? . I would like to try a fairly low cost solution to filtration and humidity control before investing a couple thousand dollars in some equipment in the attic.

It strikes me that there are two different camps for humidity control in humid environments. One camp says that a properly designed coil on the air conditioner is all that is required while another camp says that there must be a seperate device for humidity control in addition to the air conditioning coil. I guess that I find it difficult to beleive that the same air conditioner coil could keep the RH controlled inside when the cooling demand is low such as december in houston and could then keep the RH in control in the summer when cooling and dehumidifying demands are both high. It seems that there are two degrees (pun intended) of freedom in the system (moisture and temperature) that will place varying demands on keeping a home at 75 degrees and 50 % RH depending of the season and that two seperately controlled systems are required to control humidity and temperature. I guess that I'm curious about what you folks think about that opinion.

Thanks,


Kurt