If you're a lucky homeowner who owns a boat, you might have wondered if you can place a few spare air filters from your home's HVAC system on your boat for use in the boat's ventilation system. That way, you wouldn't have to worry about having to use a clogged, ineffective filter while on a long boat trip. Many boats with enclosed living and sleeping areas have HVAC systems that are supposed to remove the salt and other detritus that can get kicked up by waves. So using house system filters would allow you to buy lots of filters and save money, right? The answer is no -- an urgent no. If you use house filters in your boat's system, you can quickly make the air inside the living space quite unpalatable. In fact, you might even want to avoid using the same type of filters in coastal houses, even if the HVAC systems are otherwise exactly the same.
The location of an HVAC system -- coastal, inland, desert, at sea, and so on -- greatly influences what the HVAC system is going to have to deal with. In a coastal or marine environment, you are going to have a lot of salt in the air, as well as increased humidity in most cases. Salt from the sea air is very small and requires filters that can catch particles that small -- something many inland house filters can't do.
In addition to the size of the salt particles in general, you have their hygroscopic qualities to deal with. Salt particles can absorb moisture, so salty, humid air can have larger particles than salty, relatively dry air. If you live in an area where the coastal humidity is actually rather low, such as coastal southern California in winter versus southern Florida in summer, your house filters might miss a lot of the salt particles flowing in. You end up with that salty, rather fetid smell that is so characteristic of air right on a beach.
Filter by Location
In order to have your house and boat's systems catch as much airborne detritus as they can, you must use the right types of filters. Boat systems should always use specially-made marine filters. Coastal homes may have to use marine filters, or they could use regular filters that are able to catch very tiny particles. You may have to get a filter with a higher MERV rating
Your best bet for finding out which filters to use is to have your home or boat evaluated by HVAC repair technicians familiar with the area in which the boat or home is located. You might also be able to find out where to buy less expensive filters so that you can buy a number of spares. HVAC technicians understand how the cost can build up quickly, so they will search for solutions for you. That is the best way to keep the air in your home and on your boat as clean as possible.