Mold in heat pumps

Jamie Hall

Something to think about, which, as a steam guy, would never have crossed my mind...
http://www.cbc.ca/news/canada/nova-scotia/business-heat-pumps-mold-health-1.4559478

EBEBRATT-Ed

Don't think I would want one. And these ductless systems are all the rage right now. The number of them being sold is staggering. You would think if the condensate drained properly their could be no mold. I wonder if using them for heating is the big problem?

SuperTech

I have seen this in several ductless systems, as well as traditional split heat pumps and A/C systems. With a traditional system you can easily open it up and clean it manually, or prevent the problem with a U.V air purifier.
With a ductless system, U.V isn't an option and cleaning them properly is a process that involves usage of a coil jet coil cleaner and a mini split bib kit.

Mini splits are a royal pain to work on when they break down, cleaning them is no picnic either. I wouldn't want one in my house.

njtommy

They make UV lights for ductless now which will help.

I’ve seen the mold build up a couple times but mostly on peoples that just turn them off and on all the time. Especially on ones where they are drastically oversized.
If they are heat pumps manufacturers do tell you to run them in heat mode for a couple hours to dry them out once cooling season is done. It obviously helps limit the moisture build up in side the unit.

Harvey Ramer

I have installed, one unit in particular, that grows so much mold it pretty much stops the airflow. The mold grows on the fan blades, completely closing the gap between the blades and stopping airflow. After we became aware of it, we started cleaning it twice a year.

Many people don't understand the ongoing maintenance cost of these units. Just yesterday I managed to convince a landlord to install a gas boiler and a hydronic heating system instead of the ductless system that he was convinced that he wanted. The deciding factor was the cost of ongoing maintenance and the inherent vulnerabilities of ductless systems.
Would you install ductless units in college rentals? Me neither! Every critical component is vulnerable to the inevitable horse-play and alcohol fueled rough-housing.

Saved one on the front end

HVACNUT

When Mr. Slim came out, it was nice for people who added a 3 season room, finished basement or similar. Now they're using them as a sole heat source with no aux. to try and heat a whole house. The efficiency doesn't make up for maintenance and repair costs. The technology of the City Multi is so baffling, everything during installation must be DOBA or the system is screwed for life. We inherited a high end apartment building between the forks of L.I. It's basically a cash cow because the installation was so poor due to lack of knowledge, it will never be right without ripping the building apart.
There should be only one manufacturer of these diabolical machines, and only one head per condenser.

pecmsg

Size matters................

Most A/C are oversized but I'm finding with Minis and Variable Speed there way oversized and this is the result.

BTW the small blue filter like things in the air handler are to prevent that from happening but are only good for 6 - 12 months. Another maintenance $ item!

NY_Rob

We're also seeing mold grow on the cabin side of the AC/heater core in cars. There is a spray in kit you can get to flush it out....
https://www.amazon.com/Lubegard-96030-Evaporator-Heater-Cleaner/dp/B0007PHD0S/ref=sr_1_fkmr0_1?ie=UTF8&qid=1520527094&sr=8-1-fkmr0&keywords=automobile+air+conditioner+mold+remover

The recommendation to prevent the formation of mold is to turn off the AC a few miles from home and just run the system on fan for a few min to dry off the fins.

Jack

I wouldn't be without them. I 86'ed the entire central H&C system in my home and went mini-splits and a Rinnai DV. Zoned, efficient, quiet, comfortable. As noted the sales numbers on them is staggering and in my opinion, rightfully so. BUT...they are a pain in the neck to clean. I think the opportunity in the mini-split business is to get into the cleaning business and do only cleanings. No install, no service, no sales, just cleaning. Go to all the local installers and let them know that is your only business. You will get referrals. Everyone is so busy installing, hitting and running that no one is informing the public about the service requirement side. I do not see the mold issue here in CA because it is dryer that a bone here, but in a humid climate the drain must be installed correctly to clear all the condensate. Over time the back of the evap coil gets crapped up, but I think it is the fan that is the real problem. Load up those curved blades with organics and add some humidity and you are creating a petri dish. Drain correctly and stay up with cleaning and you are good to go. This is the same issue that resides in every category of product in our industry. People don't call for service until the equipment stops working.

EBEBRATT-Ed

Seems like a big liability issue for someone.

neilc

/\

the cleaner or the over size designer ?

Harvey Ramer

pecmsg said:

Size matters................

Most A/C are oversized but I'm finding with Minis and Variable Speed there way oversized and this is the result.

BTW the small blue filter like things in the air handler are to prevent that from happening but are only good for 6 - 12 months. Another maintenance $ item!

Those small blue filters are washable. You are right, they only last for a few months, but apparently, laying them in the sun for a few hours is supposed to recharge them.

Talking about filters, I ordered a replacement set of filters for a minisplit and it took 6 months to get them. As of right now, I have been waiting 3 months for a accessory control module for a commercial vrv airhandler.

Mark Eatherton

These units ARE displacing hydronics. In fact, the manufacturers of these units have stated publicly that they intend to take over pretty much every method of heating and cooling in the WORLD, and they are big enough, that they can. The US Army Corp of Engineers just banned them from Army bases due to the high refrigerant leak potentials. I'm sure that f they'd known about the mold issue potentials, they have banned them much sooner.

The is however, a sharp group of businessmen who are involved in the sales of hydronic components in a BIG way that have taken the initiative against the VRF industry.

Google Hydronics Industry Alliance-Commercial if you'd like to learn more. If you are a hydronics component manufacturer, you really should consider getting involved, or one day you will wake up, and find that hydronics for new construction is no more....

http://www.radiantprofessionalsalliance.org/Pages/HydronicsIndustryAlliance-Commercial.aspx

ME

Leonard

Mold.......I used to make good money selling reconditioned window A/Cs during heat waves. Every A/C that was thrown out was musty. I'ld open them up on the pavement outside, then wash them with Clorox, Tide, a tooth brush and a garden hose. And swing out the condenser to clean the dust mat off it with a toothbrush. Smelled like brand new afterwards. Did that on my 20k A/C too , never got musty again. But I washed and rinsed them outside with massive amounts of water from a garden hose.

Here in NH the pumps never ran enough days to wear out, A/Cs got tossed because either they stunk or blew hot air because condensor air flow was plugged by dust.

RayWohlfarth

My friend has a traditional heat pump in his home and he and his spouse were alwasy ill. He asked me to stop by after his HVAC company told him his system was filled with mold. I stopped by and looked in his duct and was sickened by what I saw. The duct was filled with mold, both the return and supply. I had never seen anything like it. His insurance paid to replace the ahu and the main trunks. Within 2 years, the mold was back in the supply duct. They cleaned it this time and installed two UV lamps. Weirdest thing I ever saw.

Leonard

Here in NH air is pretty dry in winter, so I decided to hang the laundry inside to dry to get humidity up and more comfortable. After a year noticed some black mold on the windows. Apparently the high humidity was condensing on window and that provided the breading ground for mold.

Problem with mold is once it starts it likely fills house with spores,that's likely why mold came back easier.

UV I've seen stinks of ozone.

RayWohlfarth

I agree Leonard. I wuld rather have ozone than mold I think

Solid_Fuel_Man

Two things I really hate about mini-splits are the cleaning and the dumb thing is outside in a snowbank in the cold when I have to change a control board/outdoor fan/recover refrigerant/etc. To top it all off there is generally a PILE of ice under it in the winter which makes it even worse to work on stand up near the thing.

My company has literally hundreds of these installed and more that we are now servicing the reasons stated above. The indoor unit mold and having r410a in my house is enough to really add the final nails in the coffin.

Mini-splits are economical to operate and do a great job at their intended purpose but have been oversold and have paper-thin copper everywhere. I've had every part of them apart and don't care for them one bit.

I've changed plenty of outdoor coils and cleaned many indoor fuzzy coils, yuck. Hydronic heat is so much cleaner than anything with a fan!

Sorry about the rant, I like fire for heating.

ChrisJ

njtommy said:

They make UV lights for ductless now which will help.



I’ve seen the mold build up a couple times but mostly on peoples that just turn them off and on all the time. Especially on ones where they are drastically oversized.

If they are heat pumps manufacturers do tell you to run them in heat mode for a couple hours to dry them out once cooling season is done. It obviously helps limit the moisture build up in side the unit.

I asked someone if I should install a UV light in my air handler.
They felt the ones sold for residential use were way too weak and believe he said I would need at least 3 commercial grade ones to be useful. I guess one to cover each side of the A coil.

You probably know who I'm talking about but I don't want to say who on here.

He's usually right when it comes to such things.

PC7060

What @Wongxxa.  

But these folks are the tile experts and I’m sure have many threads on the subject. 

https://www.johnbridge.com/vbulletin/search.php?searchid=13712596