Tag Archives for " air conditioning "

Keeping Your Vacation Home Fresh

It doesn’t matter whether your “vacation home” is a pull-behind trailer, or a luxurious condo, or a humble cabin in the mountains:  when you “get away” to a relaxing place, you don’t want to spend your precious vacation time trying to figure out how to get musty smells out or remove mold from the linens because the climate inside suffered while you were away.  Here are our tips to make it welcoming and low-maintenance!

First of all, humidity is the most important factor you’ll want to control in order to keep out mold, and you’ll want to keep the humidity under 60% all the time.  If the outside climate humidity rises over 60%, that climate will come inside and settle into soft surfaces, making them a perfect habitat for mold growth. You can only control humidity inside effectively by having a tight envelope, which means sealing up passages where outside air can penetrate in.  If no one will be living there while you’re away, you won’t need fresh-air ventilation, so make your get-away home as tight as possible by sealing windows, doors, attic doors, and other penetrations.  

Also, remember that relative humidity and temperature are closely linked.  For example, if you leave an air conditioner set on 82 degrees and the humidity rises to 80%, you may be at risk of mold forming in less than 2 weeks!  (If you’re wondering how that calculation came to be, check out this fun dew point calculator.)  In addition, relative humidity in a space will increase as temperature is lowered.   Air conditioning will naturally take some of the humidity out of the air, but there are a number of factors that can allow humidity to remain high even when your air conditioner is on. 

Here are some options to keep the humidity under control while you’re not there:

• If you have wi-fi available in your vacation home, now’s the time to take advantage of technology that can pair with existing units like mini-splits, window or portable air conditioners to enable you to monitor climate and control them remotely.  Cielo is a company that has a number of products that can help you maintain the right humidity and temperature remotely. 

• Alternatively, if you do not have wifi or app-enabled monitoring, you’ll need to choose a temperature for setting your air conditioner.  Although it’s tempting to set the temperature just under the temperature of melting plastic (haha) to conserve energy, don’t do it!  Setting the thermostat as high as 85 degrees can cause short run times and not allow the air conditioner to remove enough humidity from the air, creating an atmosphere for mold growth.  (No, You Shouldn’t Set Your Thermostat to 85F.  Here’s Why.)  For that reason, it’s ok to set it 7-10 degrees above the temperature you normally keep it while you’re staying there IF you also take into account the outdoor temperature and humidity.  There’s no magic formula for determining this ideal energy-saving-yet-mold-preventing temperature setting, but think about it: if your vacation space is in a hot, humid climate like the southeast US, you’ll want to set the maximum indoor temperature lower than the average outdoor temperature to make the air conditioning come on often enough to remove humidity.  

• Thirdly, if you don’t have a humidity control setting on your air conditioner, or even an air conditioner at all, it’s best to purchase a dehumidifier with a humidistat and set it to 60% maximum humidity.  This will ensure that humidity is being controlled, no matter what temperature the interior rises to!  Think of this dehumidifier as insurance against mold: if your air conditioner was to stop working, the dehumidifier can still keep your space mold-free if it’s suitably sized for your space.  Check out our article on different types and sizes of dehumidifiers, and be sure to set up a portable dehumidifier with a drain into a lower tub or sink that condensate can safely drain all the time.

• Leave doors to rooms and closets open for best air circulation.  Just like air purifiers, portable dehumidifiers cannot reach behind closed doors.  

• Use ceiling fans in rooms and portable fans elsewhere to keep air circulating while you’re away, which will reduce the water content in all your furnishings by evaporation.  ““Evaporation increases the humidity of the atmosphere that immediately surrounds the liquid. This humid air takes some time to dissipate into the rest of the atmosphere. The presence of a breeze, a powerful wind, or some other form of air circulation can speed up this process and make the environment of the liquid less humid. Therefore, by decreasing the humidity of the liquid’s surrounding, a powerful breeze or wind can increase the rate at which the liquid evaporates.” (Factors Affecting the Rate of Evaporation)  This is why disaster restoration companies use powerful fans to move air over wet surfaces, increasing evaporation and removal of water.  With less water in your furnishings, the chance of mold growth is reduced.   You can even add air circulation to any space that has a light socket, such as closets and pantries, by removing the light bulb and screwing in a light socket fan (which come in different designs with exposed or enclosed blades).

• Make sure your air conditioning and dehumidifier drains are clear and a clean air filter is in place before you leave!  Many homeowners have come on vacation to find their air conditioner or dehumidifier drain pan overflowing and dripping onto ceilings, floors, and other inconvenient places–what a mess that can also turn into hazardous mold!  As a homeowner, make sure to check these drains and change the filter several times during the air conditioning season, or arrange for someone to do the same while you’re away. 

• Window air conditioners need deep-cleaning sometimes.  If a musty smell is coming from the air conditioner when the fan cycles on, then you’ll know that dust has infiltrated the cooling coils, absorbed moisture, and is nourishing mold growth.  Check our article on how to deep clean it and restore the fresh smell.

• If you can, shut off water at the main valve to avoid any possible leaks, and switch off the breaker to the hot water heater if it’s electric (turn off gas if it’s gas).  This will avoid water leaks under sinks, which can make a nasty moldy mess!  If you don’t do this, at the very least shut off water to the washing machine, because burst water hoses at the washer are the single largest cause of home flooding.  (Leaving the House for 3 Days or 3 Months? 5 Must-Dos Before Your Trip)

• Bipolar ionization units like our Germ Defenders, Mobile Air Angels and Whole Home Ionizers are a great way to keep mold away too.  At the very least, plugging a Germ Defender into the bathroom will send out ions to kill mold spores in this small space where air circulation can be a challenge.

• Leaving a portable HEPA filter with activated carbon running is not a bad idea, either.  Activated carbon will help avoid that “musty” smell.  According to firesafeliving.com,  “plug-in” scent devices are not a fire hazard if you leave them plugged in while you’re away, but we at HypoAir don’t recommend them because a) many plug-ins use toxic chemicals like phthalates and formaldehyde, and b) the freshener will dry out before you return anyway, leaving an appliance running on your wall.  What’s better: make your own reed diffusers with your favorite essential oil (or combination of oils) and place them throughout your space for a safe, no-mess fresh scent!

These extra steps may seem to take more time on those days you’re packing up to leave your vacation home, but when you come back to a home that is ready for relaxing as soon as you open the doors and windows, it will be worth it!

Summer Cooling: What are our options?

Many places in the US and around the world have broken temperature records this June.  Whether you’re in Minnesota or south Texas, it can be tough to keep your home cool during summer while maintaining a decent air quality.  We’ll go over some of the most popular ways of cooling your home and maybe some you haven’t thought of.  

If you’re not familiar with the different types of air conditioners and how they work, check out this article.  Note that newer air conditioners are also often “heat pumps” that can reverse the flow of refrigerant to provide heating in the winter.   

Central Air:  About 66% of homes in the US have central air conditioning, but this is not spread out evenly over the country.  As one would expect, central A/C is more prevalent in the south (37%), west (22%), and midwest (21%), versus the northeast (17%), and newer homes are more likely to have it.  (How Much Value Does Central Air Add to Your Home?) The best thing about central air conditioning is its distribution system, which allows multiple rooms to receive cooling and filtration from one unit.  With any air conditioning, it’s very important to do the following things:

• Keep your home closed (a sealed system) so that warm, moist air is not introduced.  Letting in humid air from the outside will quickly increase humidity inside, because air at a lower temperature cannot hold as much moisture as warmer air, and humidity climbs.  This applies to windows, doors, and any significant leaks (like the door to an unconditioned attic or crawlspace).   

• Change the filter on your unit regularly!   We can’t emphasize this enough: a dirty filter not only puts extra stress on the machinery like fans and compressors, but it increases cooling costs, and when the filter gets dirty enough, air will start to leak around the filter and get your evaporator coil dirty, providing food for mold.  Using the highest MERV possible for your unit will help keep the system clean and your air clean as well.  You can check out our article here to find out how to get more filtration out of your current AC system. 

• For extra filtration, you can cut filter material to fit your vents, just don’t forget to clean or change these regularly, too. 

• Get your unit serviced regularly.  Here are some things that the HVAC tech will do for you during a service visit:  inspect the inside coils, clean the outside coils and straighten fins if necessary, check the refrigerant levels and add refrigerant if necessary, and test the thermostat.  An HVAC system is a big investment (average $7000), so you’ll want to take care of it!  

• Make sure your insulation is up-to-par: check air ducts to make sure they are not crimped and are fully insulated, and make sure there are no “bare spots” in the home’s conditioned-space envelope (ceiling or roof).  You’ve got to keep that cool air where it belongs!

Mini-Splits have most of the same parts as a central system, but they don’t have ducts to distribute cool air.  Instead, you could have one outdoor unit combined with up to eight indoor units, with the outdoor unit distributing refrigerant, not air.  In this way, you’ll have eight separate fans and filters inside, but these are smaller.  Mini-splits also have filters, so you’ll want to clean or change these on a regular basis.  One disadvantage with mini-splits is that the air filters tend to be similar to window air conditioners, which are cleanable, but they don’t provide high filtration, just large dust capture.  You will also want to get your units serviced regularly by an HVAC technician.  To get additional dust filtration, try adding standalone HEPA filters in the rooms that seem to get the most dust. 

Window Air Conditioners have come a long way in efficiency and looks!  They are one of the quickest installations, too: from buying one in your local home improvement store to having cool air in your space, could take as little as 1 hour.  Window air conditioners are a sort of “plug and play” cooling solution, but they also require regular maintenance of cleaning the filter.  Because the filter is equivalent to a very low MERV, like mini-splits, you’ll want to add a standalone HEPA filter to reduce pollen and dust.  In addition, if your window unit is more than several years old, it would benefit from a deep cleaning (see our article for tips on how to do that).   Some window air conditioners also have a feature that mini-splits and basic central systems don’t: a fresh air vent.  When this vent is open, you can get a small stream of fresh air from the outside, to dilute stale indoor air.  The only problem is that this air is usually not filtered or conditioned:  it’s the same as “cracking the window” without a screen.  To find this feature and operate it correctly, sometimes you’ll need to refer to the owner’s manual.   New window units with “inverter” type motors can be extremely efficient and this “saddle” style unit by Soleus even gives you your window view back, because it hangs below the window on each side.  It also has a dehumidifier setting to lower the humidity in your space. 

Portable Air Conditioners have become popular because like the name suggests, they are the most portable.  They can cool spaces without a window, as long as you have a place nearby to send the heat through the exhaust duct (through a sliding door with an adapter kit, for example).  You will also need a drain to collect condensate, or you will need to empty the reservoir every so often.  Portable air conditioners have the minimal filters similar to window air conditioners and mini-splits, so they are not able to filter smaller particulates.  It’s really important to clean these filters on a regular basis to keep your air conditioner working well!  Another downside to portable air conditioners is that they are less efficient than window air conditioners, and they have bulky hoses that aren’t the most attractive.  

Fans are the most common cooling systems we have, and many are cheap, at less than $50.  Fans cause evaporative cooling, where the circulated air carries heat away from our bodies in the form of water vapor.  Fans work well to cool us down if there is some humidity in the air.  (See our article about the detrimental effect of fans in extreme dry heat.)  You can use a combination of ceiling fans and portable fans to move air from cooler to warmer areas of your home.  Dreo Air Circulators are very powerful, efficient, and quiet because of the fan design, and because they use brushless DC motors that have a large range of speed with low energy consumption.  Since most fans don’t have filters, you can add standalone HEPA filters to cut down on dust, or add cloth filters to your tower fans. Filters for box fans (20x20”) are mainly the replaceable type, not cleanable, but $45 for a 4-pack of MERV-13 filters could help your space stay a lot less dusty.

Opening the windows is an option if you live outside of polluted urban areas, wildfire smoke, or excessive heat and humidity.  In these cases, it’s best to leave the windows closed and curtains drawn to preserve coolness as long as possible in the day.  If inside temperatures start to equalize with outdoors, however, you can use regular window screens in pristine areas, and Window Ventilation Filters in more polluted areas.  Although the filters restrict airflow slightly, they provide a good buffer against dust and pollen.  Here again, standalone HEPA filters will also help reduce dust in your home. 

Evaporative coolers, also known as Swamp Coolers, began to be popular in the 1920’s and 30’s when electricity was available, but residential air conditioning was not affordable/accessible. (Window air conditioners were invented in 1931 and central air conditioning was offered in 1931 but many Americans could not purchase them due to the Depression).   Swamp coolers use a fan to blow air over a wet membrane, which, if not cleaned regularly, begins to grow algae and smell like a swamp!  This older type of membrane is definitely not something we would recommend for air quality, but newer models like those made by Big Ass Fans uses a proprietary resin coating on the media that resists the growth of algae and mold to keep your airflow clean and people healthy.  Following the cleaning and maintenance guidelines are very important, too.  Another downside of this type of cooling is the massive airflow that could kick up a lot of dust.  However, if you have a large outdoor or unconditioned space and adding humidity into the air is not a problem, then an evaporative cooler could help you stay cool.  It would even help to cool a porch, from which you can open up air to your home to take in cooler air.

Heat Pump Water Heaters can actually cool your space.  It sounds counterintuitive–til you consider what this machine is actually doing.  Instead of creating heat by an electric coil or gas furnace, this type of water heater pulls heat from the surrounding air–in effect making the room in which it’s installed, cooler!  If you have the water heater installed in the garage or another unconditioned space, you can still reap the benefits by using ducts to bring warm air from your house to the heat pump, and cool air from the heat pump back to your house.  Heat pump water heaters do cost more than the basic electric or gas varieties, but according to the Department of Energy, they can be two to three times more efficient than a regular electric water heater.  However, when you consider you’re getting free cooling during the summer, you can deduct this cost from your cooling bill.  Another consideration is the size of room where it is installed.  It must be installed in a room at least 12’x12’, or have ducting to access larger areas, so it can pull the heat it needs from the ambient air.   If it’s time to replace your water heater, check with your plumber to see if a heat pump water heater would work for you!

There are many ways to move cool air from the basement into your home, but consider the quality of basement air before you make this move.  If it’s musty or moldy smelling, you’ll definitely want to get rid of that mold before trying to move that air upstairs.  For this reason, we can’t recommend circulating basement air in the rest of your home.

Whichever way you decide to cool your home, make sure that air quality doesn’t suffer.  Our Germ Defenders, Mobile Air Angels and Whole Home Ionizers sanitize air using bipolar ionization, killing microbes and agglomerating dust and pollen so it’s easy to filter or clean.   Extreme heat tends to lead to increased air pollution, so be conscious of air quality when you open the windows, or even when they are closed and outdoor air seeps in (as it always does except in the tightest of homes).   Check out our article to find out how to ride out a heat/air pollution wave safely!

Will a Radiant Barrier Help My Home’s Air Quality?

Radiant barriers have been a “hot” topic for the last few years: If to install them, where to install them, and how to install them.  Are they worth the work and cost?  It’s time well-spent to do some research before diving in with such a project.

Radiation is one of the three types of heat transfer, along with convection and conduction.  A radiant barrier is a material with a shiny surface that reflects radiant heat back outside the home.  If the barrier gets dusty or is installed incorrectly, however, it does not work well. 

According to Attainablehome.com (a builder’s website devoted to building of modern, sustainable, and high quality homes that is within reach of household incomes), properly installed radiant barriers can reduce heating costs in the hottest months in southern climates, if the home’s air conditioning system is located in the attic. It can also offer a degree of protection to that equipment when the barrier is installed over the equipment, “shielding” it. 

In colder climates, however, radiant barriers are not recommended for several reasons.

• The savings in reflecting heat away from the home in summer is minimal.

• Cold climates can allow moisture to condense behind the barrier, creating mold issues.  Perforated radiant barriers can reduce this problem, though.

What is “properly installed”?  Here is a good video showing installation of a radiant barrier over a garage.  Radiant barriers:

• Need an air gap: don’t install the barrier sandwiched between existing insulation, as it can conduct heat into it.  For instance, do not install radiant barrier foam board (such as LP’s Techshield) and sprayfoam over it. (energyvanguard.com)

• Need to be relatively clean: dust will reduce the effectiveness of the barrier, so installing on the attic floor is not recommended in most cases. 

• Must be the right type for your home/climate. There are:

• Perforated and non-perforated: Perforated barriers allow vapors to escape through the barrier, reducing the chance that moisture or mold will build up behind it.   If you live in a hot, humid climate and have a vented attic, a highly permeable barrier like “Super-Perf” from AtticFoil is recommended to allow moisture to pass through. 

• Made with insulation or board attached to the radiant surface

• Must not block air flow in the attic.  Most vented attics have soffit and ridge vents, so do not block the air flow between these two, or moisture issues may result.

In a 2010 article that still applies today, energy advisor Martin Holladay stated there are 5 factors that determine whether a radiant barrier is a good option for your home (discussed in this video):

• Do you live in a hot climate?  Yes = consider radiant barrier.

• Do you live in a humid climate?  Yes = the radiant barrier must be carefully and correctly installed so that moisture problems are not created.

• Do you have a one-story home?  One story homes tend to have larger roofs to cover the livable square feet, so a radiant barrier in a one-story home will be more effective than a two-story home of comparable square feet.

• Do you have air ducts in your attic?  Yes = consider radiant barrier to shield them.

• Is the air barrier installed correctly?  This is imperative, so the barrier has to be compatible with the insulation in your attic.

In times of low-cost energy, installing a radiant barrier may not be worth it. (energyvanguard.com)  For example, in Houston in 2011 (a hot climate in a year with similar kilowatt-hour (kwh) energy cost to today), a homeowner could save about 180 kwh per year with a radiant barrier installed on their 2000 sf newbuild home, considering that it is installed under the roof decking and the only additional cost was the more expensive barrier under the decking ($200).  This is about $25 per year savings, which would be an 8 year payback if there is no mortgage, or only about 50 cents per month if there is a mortgage (check the article for the explanation!)  It’s not a whole lot, but if energy prices go up (they will at some point), the savings could be more.

According to this video, LP Techshield (an OSB board with aluminum coating on one side) produced an 18 degree reduction in temperature in a doghouse.  Another video using the same product achieved an 8-10 degree reduction in a real house. 

So, how does all of this affect your air quality?  At HypoAir, we are in favor of not adding things that harm you or your home, so adding a radiant barrier to an existing home must be carefully considered.  Here are some steps to check whether it is right for you: 

• If you have an unvented attic, a radiant barrier is likely not to benefit you.  If you have a vented attic, make sure the vents are not blocked and there is sufficient insulation in the walls/floors of the attic facing the conditioned space. 

• Consider the current state of your attic and take temperature and humidity measurements in the attic and in the home as a “baseline”.  

• If possible, you could conduct a small “experiment” in a part of your attic that faces the sun by installing one roll only (best if it shields some ductwork) and seeing how it affects attic and home temperature and humidity.  

• If this test is favorable, continue with installation of the rest of the south- or west-facing sides.  Although I could not find much information about it, radiant heat is not very applicable on the north-or east-facing walls in the northern hemisphere. 

• If humidity increases with the test spot under similar atmospheric conditions, it’s best to terminate the experiment and remove the barrier. 

Radiant barrier material is not very expensive, so if you can install it yourself, it can provide energy savings going forward.   It’s best to take your time and research the pros and cons of installing it in your home and not succumb to pressure from a salesperson, however.  Overall, it should not increase your energy use or humidity levels, so make sure to hold the manufacturer and/or installer to their claims.  We’d love to hear from you on how radiant barrier affects your home’s atmosphere!

Why isn’t the fan making me cooler?

This is an odd post.  It’s about hitting an invisible barrier, one you don’t see until suddenly, things don’t work the way they’re supposed to.

When I see an article with the title “Fans Can Make you Hotter”, it’s an automatic click for me.  I rely on fans in every room of my home during most of the year to keep air circulating and help keep the air cooler.  How could fans ever make me hotter?

Well, we’re talking about extreme heat here: in an experiment, it was shown that fans used on volunteers in dry heat of 115 deg F heat index was more uncomfortable and detrimental than fans used on volunteers in humid heat with a heat index of 133 deg F.  In the first scenario, the lack of humidity in the circulating air caused their body temperature, strain on the heart, and thermal discomfort to increase.  In the hot and humid scenario, though, fans actually lowered body temperature and made them more comfortable.  

It’s not hard to understand why: think about a convection oven.  Above a certain temperature (104 deg F), dry air will start to impart its heat back to you, instead of whisking away heat from your skin.  Turning on a fan will only speed up the shift of hot air into the body, making you feel warmer, and potentially raising your body temperature to unhealthy levels.

In most parts of the US, dry heat like this is not a problem, but some areas of the west may certainly find it happening: garages, attics, and enclosed, unconditioned spaces quickly elevate in temperature and if there’s no humidity, be very careful of working there.  A fan in these conditions can hasten heat-related injury.  Here are some tips to stay safe:

• If necessary to work in these conditions, wet clothing and make a wet headcovering so that the evaporation of water will cool you down.   

• Take frequent breaks in a cool place (at least every 15 minutes)

• Drink more water than normal and consume electrolytes

In this case it’s not the humidity, it is the heat!