Point Of Use Water Heater vs Tankless

Point Of Use Water Heater vs Tankless

point of use water heater vs tankless

When homeowners decide to use tankless water heaters they typically want to know whether they should use a whole house tankless water heater or several point of use units, or zone units. The correct answer lies within the needs of each house and the family that occupies it. Let’s start with the structure of the home, first.

Existing Homes: Depending on the age and construction type of the house, existing homes can be very difficult to retrofit with electric lines, and running new gas lines is virtually out of the question. Therefore, in an existing home a whole house tankless water heater is usually the best way to go. Another newer option is to install an outside tankless heater. The new Bosch Anti-Freeze system makes outside installation a good option for many applications.

New Construction: If you are building a new home then running electrical lines to each application point for hot water is relatively simple, since the bathrooms, kitchen, laundry room and utility room will already be wired. In addition, if you choose to use gas-fired tankless water heaters rather than electrical, running gas line to each unit is also much easier.

Another clue for new construction is the way the home is constructed. Remember that if you use a whole house tankless water heater then water will be heated at one location and dispersed through pipes to each point of use. Once you turn off the hot water tap there will be hot water still in the line, and that water will immediately begin to cool, which produces inefficiencies and waste. If the home you are building is spacious and spread out this will lead to energy loss. And if you use metered water, you’ll watch your utility bill increase every time you turn on the tap and wait for the water to get warm.

For these reasons many new home projects employ several point of use tankless water heaters. The upfront cost is greater but the energy savings is increased substantially. For example, if your home requires 7 gallons per minute capacity of hot water it will cost less to purchase one unit capable of producing 7 g.p.m., and there are many that do, than it will be to purchase 1 unit with 3 g.p.m. capacity and 2 units with 2 g.p.m. capacity to serve various zones of the home.

However, over time the 3 separate units will use less energy combined than will the one large unit, in most homes anyway. By the way, the need for your particular home is determined by adding up the number of hot water points and their water needs, while also taking into consideration how many points are likely to be in use at any one time. A few examples: bathroom sink, .5-1.0 g.p.m; kitchen sink, 1.0-1.5 g.p.m; shower 1.5-3.0 g.p.m.; and dishwasher 1.0-3.0 g.p.m. Learn how to create a usage audit of your home to help you determine which type of tankless water heater is best for you.

That leads to the second major criterion, the water usage patterns within your family. Home energy experts suggest a whole house tankless water heater when the hot water taps throughout the home are used regularly during the day. Several people getting ready for work or school in the morning use plenty of hot water. A parent at home during the day caring for young children while cooking or doing laundry will use significant hot water. Everyone home in the evening or on weekends will also lead to greater use. A whole house unit is the right choice in these settings.

On the other hand, if certain areas of the home are used infrequently or sporadically – a utility/laundry room that only sees action on the weekend, a guest bathroom and few guests, a jetted tub in the master suite or on the deck that is more of a cold-weather toy – these scenarios make point of use models more cost effective. Break up the home into zones and service the kitchen and guest bath, for example with a 3.0-5.0 g.p.m. model, service the master suite with its own 3.0-4.0 g.p.m. unit and meet the needs of the main bath and laundry area with a 3.0-4.5 g.p.m. unit, as one possible arrangement. The layout of your home will affect the way you select zones.

It should be noted that if you choose to fuel your tankless water heater(s) with gas rather than electricity because of the lower relative cost of gas/propane then a whole house unit makes better sense. It will be more efficient and will save you the expense and hassle of trying to supply gas to 2 or 3 separate locations in the home.

Recommended Articles

We have some articles that I would like to recommend to the readers.

Foundation Repair And Maintenance

We have described here the type of foundations, what is a foundation inspection and what should be included in a good foundation inspection checklist. We can discover problems in the foundation to make us ask ourselves if it is safe to live in a house with foundation problems and what entails a foundation repair, if it is covered by homeowners insurance and its costs.

To repair a foundation, the service provider requires an underpinning system using piers: push piers vs helical piers where helical piers are preferable for residential real estate objects, despite their costs. Also when you compare helical piers with concrete footings, we can determine that helical piers are more cost-efficient than concrete footings, in my opinion.

We have water in the crawlspace: I explain what to do when the crawlspace is flooded, if it is normal to have water in the crawlspace after a heavy rain, and the importance to perform a crawlspace waterproofing thereafter, normally by installing a vapor barrier.

I describe how to improve the air quality in the crawlspace and to accomplish this, I am reluctant to use lime powder in this article, where I explain the pros and cons, as I would be using lime powder only to avoid the dangers of raw sewage under house.

We discuss the sill plate replacement cost and how to avoid the outdoor sump pump freezing, because it happened to me once.

There are always new methods for repairing foundations. One of them that we investigate here is the Powerbrace foundation repair method.

Animals can be a problem when they live near the foundation: In the following articles we describe how to remove them and how to prevent them from digging and burrowing. The articles are about animals digging holes around the foundation or when they are burrowing below concrete, below a concrete slab, or between gaps in concrete footings, for example.

In regards to basements, I describe how to solve the hydrostatic pressure in the basement. I provide to you some reasons of why we will need a certified specialist to deal with a risky sewage backup in the basement because bacteria survives a long time in a contaminated sewage and also we discuss how to deal with a basement drain backing up in general and when it happens when flushing the toilet, something that is not a DYI project at all.

Concrete

I explain here the process of concrete lifting or concrete raising, that can be done through mudjacking or slabjacking. We recommend the latter, which injects polyurethane foam.

Framing

There are some interesting articles here, in this Framing category. I refer to sistering floor joists, as a methodology to reinforce existing floor joists with some emphasis on sistering 2x6 floor joists or sistering with 2x8 instead, and about the building code for sistering joists, for sistering rafters, and the code for notching floor joists.

Water Heaters

About water heaters, we have a complete guide about water heater types and their installation requirements, about power vent water heaters, and venting in tankless devices, and I also explain in detail the difference between a mobile home water heater and a standard water heater. I also describe in detail how to remove the heating element without an element wrench using just a socket, and how to protect your water heater against the effects of hard water, and how to fix leaking.

We have some few reviews when a water heater falls into our hands, such as the Titan product portfolio, Navien lineup, the Titan N-160 reviews, the most praised by our readers, and the Rinnai R94LSi .

I study several water heater capacities and tested 20-gallon water heater units, and a comparison between point of use and tankless water heaters.

We open a tankless water heater to show how does it look like inside a tankless water heater.

After the lifecycle of the water heater is over, I reveal to you different options to proceed with its disposal.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.