Can I enclose my HVAC?

Author: Prof. Easter Price MD  |  Last update: Friday, January 9, 2026

Many homeowners intend to use basements or other areas where a furnace may commonly be installed as an additional space. This can be for simple storage, using the space as an entertainment or receiving area or other reasons. The answer is yes, of course you can enclose your furnace.

Can you build an enclosure around your AC unit?

It's recommended to have a minimum of 12'' clearance around all sides of the air conditioner and 5' clearance above it. Never box in your unit with a solid structure--you must allow ventilation through large lattices or screens!

Is it safe to enclose a furnace?

Enclosing the furnace and water heater in a sealed combustion closet can keep dangerous exhaust fumes out of your indoor air. To work effectively, the closet must: Be thoroughly sealed so no air can leak out into your living space.

Can I block an HVAC vent?

Block Off the Vent: You can block the vent by placing a piece of furniture at the opening or purchasing a magnetic damper that's strong enough to stick to the steel on the wall or ceiling. Plastic sheeting can be placed over the opening as well. You can also install a vent grille filter.

Can I put a wall around my AC unit?

The real issue here is whether or not you can successfully and get it mounted in the wall in such a way that it has sufficient air flow. If you look at the AC unit, and you can install it with the thickness of the wall all the way around the unit without obstructing its airflow, there should be no issue.

How to Install Room-By-Room Zoning in an HVAC System | Ask This Old House

Is it OK to enclose an AC unit?

Some people believe that covering the air conditioning unit when not in use will protect it from the elements, but the opposite is true. In fact, AC units are built to withstand all sorts of weather and if you cover it up, you only increase the chances that parts will rust and corrode.

How much clearance does an air conditioner need?

Space Guidelines for Air Conditioners

1-foot minimum on all sides, including behind the unit. 1.5-foot minimum for the sides and an alcove or adjacent wall. 2 feet between the sides of the unit and dense shrubs or solid fences. 6 inches between the sides and leafy plants, with a few extra inches left for growth.

Can you cover an HVAC vent?

You run the risk of causing damage to the heat exchanger

A buildup of pressure from air being pushed to covered vents can cause difficulties with your heat exchanger, causing it to shatter and release carbon monoxide into the atmosphere.

Can you block air vents in walls?

If you haven't suffered from moisture issues, you can attempt to close these vents. Remember that if this is a bedroom, you'll need to crack a window at night instead; otherwise, you'll have condensation running down the window by morning.

How to block an air conditioner?

Put a trellis in front of the outdoor air conditioner unit so it's blocked from your view. Hang small plants or flowers, or train climbing vines to cover it. Clematis, trumpet vine, and morning glory are all fast-growing vines that will quickly cover a trellis and mask your AC unit.

Can I build a wall around my furnace?

On your radar for building materials should be fire-rated 5/8" drywall & fire-rated air intake baffles if you don't use louvered doors. Think of this like wanting to build a cage for a fire breathing dragon. If you cramp him in there you'll make him mad. If he can't breathe easily, he'll also be mad.

What are the requirements for an HVAC closet?

An HVAC closet should be spacious enough to house the unit while allowing for adequate airflow and maintenance access. In general, the minimum dimensions for an HVAC closet are typically around 30 inches wide by 30 inches deep and 80 inches high.

How much clearance do you need around a furnace?

How much clearance should I leave in front of my furnace? We already stated that a space of 30 inches all around your furnace should be enough for it. Regardless, we'll recommend leaving as much space as you can; the more space, the better. That's especially true if you use a convection heater.

How do you enclose an air conditioner?

Get creative with planters and other containers to cover and hide your outdoor air conditioner unit. Use large pots, barrels, or wheelbarrows placed on their sides. Or get really creative and upcycle some old furniture into unique planters. Just make sure there's enough airflow around the unit for it to work properly.

Can I put a box around my AC unit?

Build a fence or box around your AC unit, incorporating plants and flowers between the slats. You can also install flower boxes for a taller ac unit fence.

How much space should be around an AC unit?

How Much Clearance Does HVAC Need? Make sure your HVAC unit has at least one foot of clearance around it, with two to three feet of space being better. This recommended spacing includes the distance between the HVAC unit and other structures like fences, buildings, shrubs, masonry, etc.

What happens if you block the air vent?

Even one blocked vent in the home can cause an inefficiency in air flow, which means your HVAC system will likely have to work harder to achieve the desired temperature. The result may be a home that is riddled with uneven temperatures from room to room.

Why are air vents in the walls of older homes?

Old homes were fitted with wall vents to provide a source of ventilation in the house. Before the days of air conditioning and modern heating systems, homes were often heated by coal or wood-burning fires.

Is it OK to close vents in rooms?

Closing Your Vents May Damage Your System:

Leaks that that start or get worse in your duct work can negatively impact the performance of your HVAC system. The added pressure that closed vents cause, can also lead to cracks in your heat exchanger.

Is it OK to cover HVAC?

Though the units are certainly tested to withstand icy conditions, excessive snow and ice can be damaging to the coils over time. One thing to keep in mind is that any type of plastic or airflow-restrictive covering will actually promote rusting and internal moisture damage, and therefore should never be used.

Is covering an AC vent a fire hazard?

We've seen how it can create safety hazards, mess with your home's heating and cooling, and even damage your bed. Blocked vents can cause fire risks, poor air quality, uneven temperatures, and moisture buildup. Instead of covering vents, try rearranging your furniture or using vent deflectors to direct airflow.

Can you block an air vent in a bedroom?

You will probably see one of two things - a gap between the inner and outer skins of the walls or the equivalent to a duct to the outside. If there is a gap between between both skins then you should be ok to cover up the inner skin. if it is the equivalent of a duct then I would block up the outside as well.

Can you build an enclosure around an AC unit?

Plants aren't the only way to conceal your air conditioning unit. When you want something easier to move or remove, create an outdoor air conditioner enclosure. Fence panels, old shipping pallets and classic trellis structures are just a few of the options available.

How close can an air conditioner be to a wall?

We recommend 2-3 feet of clearance on all sides of your condenser unit. If you don't have proper clearance around your AC unit, it will prevent proper airflow. This will lead to: High energy bills.

What is HVAC clearance?

Generally speaking, HVAC professionals will tell you that there should be at least one foot of clearance on each side of the unit – however, there may be some manufacturers who recommend a longer distance, such as two feet on each side.

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