Ideal indoor humidity in Pueblo: what the numbers mean

What ideal indoor humidity means for a Pueblo home

The ideal indoor humidity in Pueblo homes is a range of values. The EPA advises keeping indoor humidity below 60%, ideally 30 to 50%.

Humidity here means relative humidity: the share of moisture the air is holding compared with the most it could hold at its current temperature. Air with too much moisture feels sticky and can grow mold. Air with too little feels dry and scratchy.

What is the difference between relative humidity and dew point?

Relative humidity changes with temperature. Warm the same air and the percentage drops. Cool it and the percentage climbs, even though no water was added or removed.

Dew point is steadier. It is the temperature at which air can no longer hold its moisture, so water starts to condense on a surface. A higher dew point means more moisture in the air, whatever the thermostat says.

For a sense of scale, the average July dew point at the NOAA weather station near Pueblo is 50.9°F. That is an outdoor number. Indoors, the reading you can take yourself is relative humidity, and the heating and cooling equipment has a big say in it. The Pueblo HVAC page covers that equipment.

How do a furnace and an AC change indoor moisture?

A furnace warms air but does not add water to it. The average December to February daily low at the NOAA weather station near Pueblo is 16.0°F, and cold outdoor air carries very little moisture. When that air leaks into a house and gets heated, its relative humidity falls. The same station averages 152 days a year with a low of 32°F or below, so heated indoor air can read dry for much of the heating season.

An air conditioner works the other way. Warm indoor air passes over a cold coil, and moisture condenses on the coil and runs out through a drain. Summer highs matter here: June to August days average a high of 90.5°F at the station, and 74 days a year reach 90°F or more. On days like those, the AC removes moisture as a side effect of cooling.

Airflow matters in both seasons. A coil with weak airflow across it cools and dries the air poorly, and a dirty filter is a common reason. ENERGY STAR advises inspecting, cleaning or changing air filters in a central air conditioner, furnace or heat pump once a month. The guide to a monthly filter look walks through that routine.

How can you check humidity at home?

A small gauge called a hygrometer reads relative humidity. Many are small, simple and sit on a shelf. A few steps give a useful picture:

• Set the gauge at chest height, away from the kitchen, the bathroom and any vent.
• Let it sit for a while so the reading settles.
• Move it to a bedroom and the main living room and compare.
• Read it in the morning and again in the evening.
• Compare what you see with the EPA range.

Your senses add clues. Fogged windows, a musty smell or damp patches on a wall point to moisture that is too high. Static shocks, cracked wood trim or a dry throat point to air that is too dry.

A single reading can mislead. Showers, cooking and a pot of boiling water all push the number up for a while. Look for a pattern over several days.

What can you adjust, and what is contractor work?

Some steps are safe for any homeowner. Run the bathroom and kitchen exhaust fans while you shower or cook. Keep supply vents and return grilles uncovered, and keep the filter fresh. Leave a few feet of space around the outdoor unit. A portable humidifier or dehumidifier can nudge one room, if you empty and clean it as its maker directs.

Other work needs a licensed contractor. A whole-house humidifier ties into the furnace, the water line and the wiring, so a licensed contractor installs it. Refrigerant work on an AC coil, electrical parts and sealed components are also contractor jobs. Switch the power off before you ever open a panel, and for most homeowners it is better to leave panels closed.

Water at the indoor unit deserves attention too. Some moisture is normal, since it drains away as the AC runs. Pooling water, a wet pan or a dripping ceiling points to a drain or coil problem, and a licensed contractor checks it.

If moisture seems tied to the furnace, keep two safety lines in mind. If you smell gas, leave the house, then call the gas utility from outside. If a carbon monoxide alarm sounds, get everyone out and call emergency services.

When does a humidity problem point to the equipment?

Readings that stay outside the range after the simple steps are worth a closer look. An AC that runs and runs without drying the house, a furnace that leaves the air very dry, or damp spots that keep returning can all trace back to airflow, ducts or the equipment itself.

The US Department of Energy says regular maintenance, such as charging refrigerant and replacing filters, is necessary to keep central air conditioners at peak performance. How often a system needs service is something the contractor advises on.

Waiting has a cost of its own. Moisture that lingers feeds mold and can stain ceilings. Very dry air can crack wood and irritate the throat.

Taking humidity readings to an HVAC contractor

Jot down the readings, the rooms they came from and whether the furnace or AC was running. Those notes give a licensed contractor a clear place to start.

For help with heating and cooling in Pueblo, start at the HVAC in Pueblo page.