Monitoring Indoor Air High quality and Offering Information Based mostly Options

Gary McCreadie is an HVAC tech, the creator of hvacknowitall.com and the HVAC Know It All Podcast

Preface: This text with embedded podcasts was designed to teach contractors on indoor air high quality and indoor air high quality monitoring.  Please use this text as a device to teach your clients, assist them keep knowledgeable and updated.   

The Three Essential Elements

Shortly after the world was left in a kerfuffle by the Covid 19 pandemic, I jumped onto a podcast with Brandon Glancy from  Aprilaire to debate the three important components of indoor air high quality.  It was an eye fixed opening dialog about issues I knew about already however had by no means actually spent the time to deep dive into.

The three important components of IAQ embrace: humidity, filtration and air flow.  If we are able to management these components whereas in fact sustaining a cushty indoor temperature, we are able to create superior high quality indoor air of our buyer’s properties and companies, together with our personal.  This can be very vital for HVAC professionals to achieve a robust understanding of those components, the way to seize the information and the way to rectify the problems offered from the information.  Lets focus on these components briefly.  

Take a look at the podcast episode to study extra

Humidity 

It appears logical {that a} constructing ought to be maintained at a cushty humidity stage, an excessive amount of humidity can create moisture and potential mildew points, too little could make if really feel dry and create static electrical energy when sliding on the work pants within the morning.  Too excessive or too low could be a figuring out consider constructing materials injury reminiscent of flooring, there are studies stating that airborne viruses journey simpler in dry air.  I’ve additionally learn a number of studies that present increased humidity ranges assist to include viruses as they’re contained in “heavier” water droplets that finally fall to the bottom.  The identical studies state that 40% – 60% RH is the perfect set level to assist with the unfold of viruses.  Take into account that extreme humidity can create condensation on home windows or areas of a constructing with air infiltration in colder ambient temperatures.  This occurs as a result of the constructing materials is at or beneath the air’s dew level, preserve this in thoughts when establishing indoor humidity, this can be attributed to poor air flow as properly, particularly whereas cooking.  

Typically talking, we must always humidify an area within the winter and dehumidify an area in the summertime.  There are lots of merchandise in the marketplace that may assist with this.  An air con system will take away moisture simply by nature of design, when moisture embedded in the air contacts the chilly evaporator coil, the water vapour will condense, stream down the coil into the drain pan and exit out the drain line.  However, what if the humidity stage within the dwelling or constructing remains to be excessive as soon as the thermostat has glad?  At this level additional de-humidification is required, a devoted de-humidifier may help with this job with out additional cooling the house. 

That is the place monitoring is vital, if the thermostat within the house has been glad as per the thermostat cooling set level however the humidity proportion remains to be excessive, the house is in danger for moisture injury to constructing supplies and potential mildew points.  De-humidifiers work by first cooling the air to take away moisture like a conventional air con system after which re-heat the air so it does not additional drop the temperature within the house.  

Expample of an Aprilaire 1830 70 pint dehumidifier 

Filtration 

Throughout my profession I’ve modified out many MERV 8 filters (MERV stands for minimal effectivity ranking worth), this has been the norm, they do pretty properly to guard tools from dust/particles however a great evaporator cleansing remains to be wanted sometimes.  The MERV ranking system was developed by ASHRAE (The American Society of Heating Refrigeration an Air Conditioning Engineers).  Typically, the system was created to point out the effectiveness of every filter in every MERV class.  Later within the article I’ll share a chart that helps higher clarify.  

Throughout my podcast episode with Brandon, we mentioned how MERV 13 ought to be the minimal requirement to guard not solely the tools but in addition to filter out particulate that may be dangerous to people.  Having the ability to measure PM2.5 in an area is extraordinarily vital, particularly when planning a filtration answer for a selected house.  PM2.5 basically phrases is a measurement of particulate within the air and is an business measurement commonplace, PM stands for “particulate matter” and a couple of.5 is the measurement of the particle, measured at 2.5 micrometers.  Why ought to we be involved with measuring PM2.5?  Particulate matter at this dimension and beneath is categorized as fantastic and might pose higher well being dangers.  Because of this the business is pointing at MERV 13 as a minium commonplace to guard people.  A MERV 13 filter has the potential of capturing particulate from 0.3 to 1 micrometers in accordance the chart beneath, which is linked to an article by Nationwide Air Filtration Affiliation.  

The Covid 19 pandemic has had dwelling house owners and constructing managers inquiring about MERV 13 filters.  I’d encourage HVAC contractors to not blindly set up a MERV 13 filter and take into account it completed.  An air stream baseline take a look at ought to be carried out with the prevailing filter after which with the MERV 13 to make sure the system can deal with the added air stream resistance.  A cooling and heating verify must also be carried out as properly to make sure there isn’t any extreme temperature rise throughout the warmth exchanger and cooling system shouldn’t be in jeopardy of freezing as a consequence of probably decrease air stream.  It’s also advisable that the filter is monitored periodically as it could load up quicker relying on the setting.

Air flow 

Air flow performs an enormous function in IAQ.  There isn’t a higher strategy to ventilate than to rid of present air after which to interchange it with new outdoors air, the easiest way to perform that is with an HRV (warmth restoration ventilator) or an ERV (vitality restoration ventilator) relying on the wanted necessities.  By not ventilating air, there could be a potential construct up of VOCs (risky natural compounds), CO2 (carbon dioxide) and moisture. 

I’ve an HRV in my dwelling and ran an experiment.  With the HRV off, the house accrued roughly 1100 ppm in CO2, with the ERV on for twenty-four hours, the CO2 dropped off to roughly 700 ppm.  Relying on the place you reside, outside CO2 is roughly 400 ppm.  The utmost advisable CO2 ppm indoors as per ASHRAE is 1000 ppm.  I ran an experiment with the HAVEN IAQ monitor, I sprayed a well-liked glass cleaner into the return air grill and watched the VOCs rise. The experiment was carried out in two components, the primary experiment was carried out with the HRV operating at minimal pace, the second half was carried out with the HRV off.  The identical return air grill was used for each experiments, 5 sprays of cleaner was carried out for every experiment, and there was a one hour span after shutting down the HRV.  

You will discover from the pictures beneath, that the chemical content material (VOCs) is a lot decrease with the HRV operating on minimal pace earlier than the introduction of chemical compounds and comparatively increased with the HRV off.  The introduction of chemical compounds elevated the VOC content material from the preliminary baseline take a look at in each experiments and anecdotally, with the HRV off, the odor of chemical compounds was observed nearly immediately across the dwelling. 

Because of this monitoring performs an enormous function in IAQ, if we do not monitor the indoor air, we won’t present an answer to restore the problem.  On this case, the proof exhibits that including a air flow system will assist with total VOC content material throughout the house.    

These assessments have been carried out with the Haven IAQ Central Air Monitor, a duct-mounted, HVAC-integrated, whole-home, professionally supported IAQ technique.  

Haven IAQ app readings with HRV at minimal pace earlier than chemical introduction 

Haven IAQ app readings with HRV at minimal pace after chemical introduction 

Haven IAQ app readings with HRV off earlier than chemical introduction 

Haven IAQ app readings with HRV off after chemical introduction 

To study extra about HRVs and ERVs hearken to this podcast episode with Venmar

Right here is one other experiment I carried out utilizing the Haven IAQ monitor measuring PM2.5 within the return air duct earlier than the filter

Desk Prime IAQ Screens

Here’s a piece written by Ben Reed on desk prime IAQ displays.

Indoor air high quality displays come in numerous type components – some sit in your counter or desk, some have a battery and will be carried round, whereas others are mounted to the wall. Most have the power to measure the quantity of particles and chemical compounds at various levels of accuracy and repeatability, although some gadgets are outfitted with specialised sensors for sure gases or radon.

One attribute these indoor air high quality displays have in frequent is that they measure air solely within the room the place they’re at present positioned. Moveable displays will be moved from room to room, however it might probably by no means measure all rooms without delay. As well as, most stationary or moveable displays measure particles utilizing the identical method: a small fan that forces the air via a laser beam. This system works properly, however these small followers have mechanical components that may fail if the system is dropped, if the motor or bearing fails, or if too many massive particles clog the tiny air channel. To summarize, frequent air high quality displays solely measure one room at a time and have transferring components that may fail after a couple of years of use.

Most fashionable single household properties have a central air methods that’s designed to maneuver the air all through the entire dwelling whereas heating or cooling. Typically talking, a house’s air is circulated by the central HVAC system first via the return ductwork, then into the filter, air handler, then again out to the house by way of the availability ductwork. So why monitor the air in just one room if there’s a location that each one of a house’s air is being moved via?

In Duct Central IAQ Monitoring

Ben is the VP of Merchandise at Haven IAQ by Tzoa, their staff reached out to me a couple of months again to carry out an set up and testing of their in-duct central IAQ monitor, or central air monitor or CAM for brief.  I’m all the time intrigued with new know-how and studying intensely in regards to the HVAC business, I gladly accepted.  

The set up was simplified via an tutorial YouTube video and stroll via on the Haven IAQ app.  The set up merely requires a small gap within the duct, a 24v energy supply (from the air handler, or plug in supply) and minimal arrange on the app.  This work ought to be carried out by a educated HVAC skilled.  

The shear benefit of a central air monitor vs. a stationary room monitor is that the house or constructing’s blended air, from every room, is captured and analyzed.  Whereas testing the Haven IAQ monitor I used to be capable of get the wanted information, so far as IAQ, from the Haven IAQ app. The Haven IAQ Professional Portal gives elevated analytics, with trending and reporting capabilities.  

Take heed to Ben and I focus on this subject on a podcast episode 

Selecting The Proper Answer

What all this has taught me, is there isn’t any actual “one dimension” suits all answer for IAQ in an area.  I not too long ago had a buyer attain out, they wished us to put in an air air purifier for a hydronic air handler in a small workplace house.  I advisable we analyze the air first, I put in a Haven IAQ CAM and what I discovered was fascinating.  The workplace house is constructed inside a bigger workplace tower, the constructing air is handled throughout enterprise hours however then units again within the night and shuts down for the vitality price financial savings.  Because the smaller workplace throughout the tower, is occupied 24 hours, the evening shift does not have the benefit of absolutely handled indoor air, the “cooling solely” supplemental air handler is left to work alone.  It cools the house simply fantastic, nevertheless it was observed that the humidity within the house dropped off in night to beneath 30% RH.  The VOC content material was low, because of the truth the ceiling house above the workplace has outdoors air infiltration and it appeared to work properly at conserving the house ventilated with recent air.  As a constructing will increase in age, there’s a higher probability of air leakage…However that is for a unique article.  

PM2.5 was additionally within the low vary, however there may be lacking occupancy due Covid 19 and folks working from dwelling.  I am discovering many unoccupied websites the place filters usually are not close to as loaded in comparison with pre pandemic.  We might want to monitor this nearer, as soon as the workplace employees begins to maneuver again in.  For now, the one advice for this web site is including a humidifier, as now we have proof to point out that humidification is required in the course of the night and thru the evening.  We’ll want to do some additional monitoring in the summertime months to make sure that humidity ranges do not rise throughout off constructing hours.  

We’ve got the know-how to watch IAQ, lets harness it to supply the correct options for our properties and our clients.  

Gary McCreadie

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