In this Question and Answer session, we sat down with Clark Zacaroli, Clark is a business development manager for Runtal North America, division of the Zehnder Group, a Swiss manufacturing organization focused on indoor air quality and comfort systems. Clark has spent the better part of 30 years working internationally in the heat transfer industry, including industrial and HVAC segments.


Clark, Why are bathrooms always so cold?

It comes down to 5 main reasons:

1) The use of the room: Not like any other room in the house

a)  The first is the nature of the bathroom itself. It’s the one room in the house where you typically don’t have clothing on.

b) It’s also the only room in the house where you’re wet.

So naturally you would want the bathrooms to be warmer than the rest of the house in order to be comfortable.

2) Bathroom design is not conducive to “warmth”.

Because of all the hard surfaces in the room tiling, porcelain mirrors, windows. The room feels much cooler than other rooms. All of these hard surfaces actually reflect the cold that’s in the room. In other words, when you’re standing in front of them, they actually make you feel cold because they’re colder than the air temperature typically.

3) Evaporative cooling effect

Third reason is air movement. Most bathrooms have exhaust fans in them. They have to have exhaust fans to meet building codes and so just by having moving air when you get out of the shower, it’s like getting out of the pool on a breezy day. Your wet skin temperature is much higher than the air because of the warm shower, and as the moisture evaporates it makes it feel even colder than the air temperature actually is. The evaporation effect is taking the heat away from your body.

4) Typical HVAC design is not bathroom friendly

To make matters worse, the bathroom is often not heated as effectively as the rest of the house may be. In typical forced air systems for example the bathroom is at the end of the main line of ductwork. By the time the heated air from the furnace or heat pump reaches the bathroom, it is cooler than other rooms. This is designed purposely to make sure the air in the bathroom can be exhausted properly by the separate, exhaust fan.

So we have the one room where you are most exposed and wet with a combination of factors which make it the coldest room in the house.

To remedy the situation, there are a few known products such at “forced air heaters” which are small units often built into a wall, which have an electric element which heats up and a fan which blows the warm air into to room. . Unfortunately, in order to feel warm in that bathroom, adding more hot air is not going to help you because hot air is not going to heat the surfaces in the room and it’s also going to mean more “moving” air.

So no matter what you do, the only solution that you have in a bathroom to feel comfortable and warm is something that radiates heat, like the sun.

An old technique that used to be used was using a radiant light bulbs. If you remember, there’s a timer on the wall and you would click, click the timer and this thing would come on and feel like the sun if you were directly below it. And that’s precisely what that was for, however is very inefficient and heats only the small area directly below the bulb.

I have seen some people using fireplaces, but the reality there is something like that is super, super expensive and probably not realistic for most homeowners.

Not realistic, very expensive – yes and for for most homeowners and very difficult to have approved by many building codes.

A fantastic solution is to have a radiant heat source somewhere in the bathroom which is large enough to reach most of the room, yet works with the design scheme. The reason the radiant is so effective is that it is in fact, just like the sun, it heats the objects in the room, not the air. So now all of those hard surfaces can work to your benefit (tiles and your tub, shower, sink, toilet) All of these hard surfaces are actually warming up and reflecting heat.  Also, the radiant heat source is projecting radiant heat on your body when you get out of the shower or when you’re standing there with very little clothing on, just like the sun would. The feeling of warmth is 100 percent on the objects in the room. Further, it takes very little time to “warm up” so you only really need to have it on a short while before you are using the room, making it efficient. Add to that certain products / accessories such as towel racks, and you have a double benefit. Not only do you have the radiant heat coming the towel radiator, you also have a dry and warm towel. In terms of comfort and hygiene you’re drying the towel, not just warming it up. The Runtal Omnipanel II product line is designed specifically for these applications.

Do you ever see anybody use baseboard radiators in bathroom situations or is it mostly the towel warmer?

Well, baseboard comes into two main forms of heating, one is called convection, where the surface of the baseboard is cold, typically a sheet metal cover. Inside it is an element which heats up which is in fact heating the air in the room. The heat created by the element creates convective circulation because hot air rises. It works “OK” but nowhere near as effective as a radiant baseboard heater, which in fact will have all of the benefits of the radiant heat described above, as well as a certain amount of convective heating. Bathrooms can be tough for baseboard heating however because there is not a lot of low wall space.  Another reason a combination product like the Omnipanel II is a terrific solution because it goes on the wall where you typically have a towel bar hanging anyway.

I see a lot of people trying to compare heated flooring vs towel warmers and baseboard radiators. What’s the difference in your opinion?

Radiant flooring is a great solution because the floor is typically tile and it’s very cold. So you’ll have the sensation of heat on your feet when you’re walking around in and it can be effective in terms of heating the bathroom, but it’s not going to give you that. “I’m standing in the sun warm” feeling. The more direct contact with your body, the more comfort you will experience when it comes to radiant heat. Again, a product on the wall such as a towel radiator is “shining” heat right on you.

These are good options for other parts even other parts of your home outside of your bathroom. Is that correct?

Absolutely. Anyplace where you’re going to fight cold inflitration or hard surafces. Entryways are very good spots to have radiant heat for a couple of reasons. One, you are always opening the door and the cold air is coming in, and chilling down the objects and wall surfaces in that area. No matter what happens,that area feels cold.  If you have radiant heat in the area however, even if the air is cold your body feels the heat  sort of like standing by a bonfire on a chilly evening. Further the panel can also serve as a coat rack. There you go, put your coat on and it’s nice and warm AND it’s dry.

Kitchens are another place that’s interesting because of a difficult or limited wall space options and hard surfaces again  In this case you have great options with the baseboard product, utilizing area which are normally dead space such as underneath cabinets and places where it can be actually hidden more than it is, you know, an architectural part of the room.

Why would someone want to take a look at Runtal products versus all the other ones that are on the market today?

Well, Runtal products are by far the highest quality equipment on the market today, and are a solid investment. Not only do the products have superior performance, everything from the materials of construction to the end product finish make these product unique and extremely durable. With Runtal your design options are also virtually limitless.

Take for example our towel radiator products. We do not refer to them as “towel warmers”. Our products create enough heat to give you radiant heating in the bathroom as well as warm, but more importantly DRY the towels. Typical towel how warmer products are, no more than say a hot air curling iron They’re light weight, and only designed to be decorative and warm.